Molecules and uses therefor

Abstract

Disclosed are inhibitors of voltage-gated sodium channels. More specifically, the present disclosure relates to Nav1.1 and Nav1.7 inhibitors and their use for treating or inhibiting the development of a condition in which inhibiting Nav1.1 and / or Nav1.7 activity is associated with effective treatment or inhibition, such as pain.

Description

TITLE “MOLECULES AND USES THEREFOR”

[0001] This application claims priority to Australian Provisional Patent Application No. 2024902111 entitled "Molecules and uses therefor" filed 9 July 2024, the contents of which are incorporated herein by reference in their entirety. FIELD

[0002] The present disclosure relates generally to inhibitors of voltage-gated sodium channels. More specifically, the present disclosure relates to Nav1.1 and Nav1.7 inhibitors and their use for treating or inhibiting the development of a condition in which inhibiting Nav1.1 and / or Nav1.7 activity is associated with effective treatment or inhibition, such as pain. BACKGROUND

[0003] The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

[0004] Voltage-gated sodium channels (Nav) are complex transmembrane proteins comprised of a pore-forming α-subunit and accessory β-subunits that play an essential role in the initiation and propagation of action potentials in excitable cells. Nav channels open to permit influx of sodium ions when the membrane potential is depolarised and close on repolarisation. They also close on continuous depolarisation by a process termed inactivation, which leaves the channel refractory (i.e. unable to open again for a period of time).

[0005] Humans have nine different Nav channels which are found in the heart, muscles, and the central and peripheral nervous system. Their distinct tissue distribution as well as amenability to modulation by toxins and drugs have led to significant interest in Nav channels as therapeutic targets in a number of poorly treated conditions, ranging from epilepsy to cardiac arrhythmias and pain. Pharmacological inhibition of Nav channels is a possible therapeutic strategy for the treatment or prevention of a range of conditions. Channel selectivity is also an important consideration for developing more effective treatments, as major off-target activity may affect the therapeutic window and result in adverse effects. However, achieving sufficient selectivity for one sodium channel isoform over another is challenging due to the high sequence homology within the Nav family.

[0006] Irritable bowel syndrome is a common gastrointestinal disorder which affects 11% of the global population. Irritable bowel syndrome patients have chronic orrecurrent abdominal pain and altered bowel habits. However, opioid based ‘pain killers’ are addictive and ineffective in irritable bowel syndrome and adequate treatments are lacking.

[0007] The human gastrointestinal tract is innervated by sensory nerve endings. Chronic abdominal pain associated with irritable bowel syndrome is caused by the pain sensing nerves in the colon becoming hypersensitive, thereby conducting pain signals in response to stimuli that would not normally cause pain. As such there is a need for the development of effective treatments for pain, especially pain originating from the abdomen, and including pain associated with gastrointestinal disorders such as irritable bowel syndrome. SUMMARY

[0008] The present disclosure is predicated in part on the design of peptides derived from the amino acid sequence of Hs1a isolated from the venom of the theraphosid spider, Hysterocrates sp. (Nigeria), which inhibit the voltage-gated sodium channels Nav1.1 and Nav1.7. While native Hs1a inhibits Nav1.1, Nav1.7 and Nav1.6, the peptides described in the present disclosure have selectivity for inhibition of Nav1.1 and Nav1.7 over other sodium channel subtypes, such as Nav1.6, thereby improving the suitability of these peptides as therapeutics. Based on this activity, the peptides of the present disclosure are considered to be useful for treating or at least partially inhibiting the development of conditions in which inhibition of Nav1.1 and / or Nav1.7 activity is associated with effective treatment or amelioration of such conditions, non-limiting examples of which include pain such as inflammatory pain, visceral pain, abdominal pain and nociceptive pain, and anxiety.

[0009] Accordingly, in one aspect, there is provided a molecule comprising an amino acid sequence represented by Formula I: CLX1X2X3X4ACNPX5NDKCCANX29VCSX6X7HX8X9C (I) wherein: X1 is a small amino acid residue or an acidic amino acid residue; X2 is a hydrophobic amino acid residue or a small amino acid residue; X3 is a hydrophobic amino acid residue; X4 is a small amino acid residue; X5 is a basic amino acid residue; X6 is a small amino acid residue or a basic amino acid residue; X7 is a basic amino acid residue; X8 is a basic amino acid residue; X9is any amino acid residue; andX29 is any amino acid residue, wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1: NDCLGFWSACNPKNDKCCANLVCSSKHKWCKGKL [SEQ ID NO: 1].

[0010] In some embodiments, X1 is selected from A, S, G, T, D, E and modified forms thereof; X2 is selected from M, I, L, V, F, Y, W, Nle, 4-benzoyl-L-phenylalanine (Bpa), 4,4’-biphenylalanine (Bip), A, S, G, T and modified forms thereof; X3 is selected from M, I, L, V, F, Y, W, Nle and modified forms thereof; X4 is selected from A, S, G, T, homoserine (hS) and modified forms thereof; X5 is selected from R, K and modified forms thereof; X6 is selected from A, S, G, T, R, K and modified forms thereof; X7 is selected from R, K and modified forms thereof; X8 is selected from R, K, homoarginine (hR), diaminobutyric acid (Dab) and modified forms thereof; X9 is selected from M, I, L, V, F, Y, W, Nle, Bpa, Bip, A, G, S, T and modified forms thereof; and X29 is selected from M, I, L, V, F, Y, W, Nle, A, G, S, T and modified forms thereof.

[0011] In some embodiments, X1 is selected from G and E; X2 is selected from F, Bip, A and Bpa (e.g. Bip); X3 is W; X4 is selected from S and hS; X5 is selected from K and R; X6 is selected from K and S; X7 is selected from K and R; X8 is selected from K, R, Dab and hR; X9 is selected from W, Bpa, A and Bip (e.g. A); and / or X29 is selected from L and A.

[0012] In some embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence represented by Formula II: X10X11X12CLX1X2X3X4ACNPX5NDKCCANX29VCSX6X7HX8X9CX13X14X15X16 (II) wherein: X1to X9and X29are as defined for Formula I; X10 is absent or is a small amino acid residue; X11 is an amide-containing amino acid residue; X12 is an acidic amino acid residue; X13 is a basic amino acid residue; X14is a small amino acid residue; X15 is a basic amino acid residue; and X16 is a hydrophobic amino acid residue.

[0013] In particular embodiments, X10 is absent or is selected from A, S, G, T and modified forms thereof; X11 is selected from N, Q and modified forms thereof; X12 isselected from D, E and modified forms thereof; X13 is selected from R, K, hR and modified forms thereof; X14 is selected from A, S, G, T and modified forms thereof; X15 is selected from R, K, Ornithine (Orn) and modified forms thereof; and X16is selected from M, I, L, V, F, Y, W, Nle and modified forms thereof. In exemplary embodiments, X10 is G; X11 is N; X12 is D; X13 is K, R or hR; X14 is A or G; X15 is K or Orn; and / or X16 is L.

[0014] The molecule of the present disclosure may, alternatively, comprise, consist or consist essentially of an amino acid sequence represented by Formula III: GNDCLGX2WX4ACNPX5NDKCCANX29VCSSKHX8X9CKAX15L (III) wherein: X2, X4, X5, X8, X9 and X29 are as defined for Formula I; and X15 is Orn.

[0015] In some embodiments, X2 is F, A or Bip; X4 is S or hS; X5 is K or R; X8 is K or Dab; X9 is W, A or Bpa; and / or X29 is L or A.

[0016] In another aspect, there is provided a molecule comprising, consisting or consisting essentially of an amino acid sequence represented by Formula IV: CLX1X2X3X4ACNPX5NDKCCANLVCSX6X7HX8X9C (IV) wherein: X1 is a small amino acid residue or an acidic amino acid residue; X2 is a hydrophobic amino acid residue; X3 is a hydrophobic amino acid residue; X4 is a small amino acid residue; X5is a basic amino acid residue; X6 is a small amino acid residue or a basic amino acid residue; X7 is a basic amino acid residue; X8 is a basic amino acid residue; and X9 is a hydrophobic amino acid residue; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1: NDCLGFWSACNPKNDKCCANLVCSSKHKWCKGKL [SEQ ID NO: 1].

[0017] In some embodiments, X1 is selected from A, S, G, T, D, E and modified forms thereof; X2 is selected from M, I, L, V, F, Y, W, Nle, 4-benzoyl-L-phenylalanine (Bpa), 4,4’-biphenylalanine (Bip) and modified forms thereof; X3 is selected from M, I, L, V, F, Y,W, Nle and modified forms thereof; X4 is selected from A, S, G, T, homoserine (hS) and modified forms thereof; X5 is selected from R, K and modified forms thereof; X6 is selected from A, S, G, T, R, K and modified forms thereof; X7is selected from R, K and modified forms thereof; X8 is selected from R, K, homoarginine (hR), diaminobutyric acid (Dab) and modified forms thereof; and X9 is selected from M, I, L, V, F, Y, W, Nle, Bpa, Bip and modified forms thereof. In particular embodiments, X1 is selected from G and E; X2 is selected from F, Bip and Bpa; X3 is W; X4 is selected from S and hS; X5 is selected from K and R; X6 is selected from K and S; X7 is selected from K and R; X8 is selected from K, R, Dab and hR; and / or X9 is selected from W, Bpa and Bip.

[0018] In some embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence represented by Formula V: X10X11X12CLX1X2X3X4ACNPX5NDKCCANLVCSX6X7HX8X9CX13X14X15X16 (V) wherein: X1 to X9 are as defined for Formula IV; X10 is absent or is a small amino acid residue; X11 is an amide-containing amino acid residue; X12 is an acidic amino acid residue; X13 is a basic amino acid residue; X14 is a small amino acid residue; X15 is a basic amino acid residue; and X16 is a hydrophobic amino acid residue.

[0019] In particular embodiments, X10 is absent or is selected from A, S, G, T and modified forms thereof; X11 is selected from N, Q and modified forms thereof; X12 is selected from D, E and modified forms thereof; X13 is selected from R, K, hR and modified forms thereof; X14 is selected from A, S, G, T and modified forms thereof; X15 is selected from R, K, Ornithine (Orn) and modified forms thereof; and X16 is selected from M, I, L, V, F, Y, W, Nle and modified forms thereof. In exemplary embodiments, X10 is G; X11 is N; X12 is D; X13 is K, R or hR; X14 is A or G; X15 is K or Orn; and / or X16 is L.

[0020] The molecule of the present disclosure may, alternatively, comprise, consist or consist essentially of an amino acid sequence represented by Formula VI: GNDCLGX2WX4ACNPX5NDKCCANLVCSSKHX8X9CKAX15L (VI) wherein: X2, X4, X5, X8 and X9 are as defined for Formula IV; andX15 is Orn.

[0021] In some embodiments, X2 is F or Bip; X4 is S or hS; X5 is K or R; X8 is K or Dab; and / or X9 is W or Bpa.

[0022] In specific embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence represented by any one of SEQ ID NOs: 2-33: GNDCLGFWSACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 2]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 3]; GNDCLGX19WSACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 4]; GNDCLGFWX20ACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 5]; GNDCLGFWSACNPRNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 6]; GNDCLGFWSACNPKNDKCCANLVCSKKHKWCKAX17L [SEQ ID NO: 7]; GNDCLGFWSACNPKNDKCCANLVCSSKHX21WCKAX17L [SEQ ID NO: 8]; GNDCLGX19WSACNPKNDKCCANLVCSSKHX21WCKAX17L [SEQ ID NO: 9]; GNDCLGX19WX20ACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 10]; GNDCLGX19WSACNPRNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 11]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX18CKGX17L [SEQ ID NO: 12]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX18CKAKL [SEQ ID NO: 13]; GNDCLEFWSACNPKNDKCCANLVCSSKHKX18CX22GKL [SEQ ID NO: 14]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX18CX22GKL [SEQ ID NO: 15]; GNDCLEFWSACNPKNDKCCANLVCSSKHKWCX22GKL [SEQ ID NO: 16]; GNDCLEFWSACNPKNDKCCANLVCSSKHKX18CKGKL [SEQ ID NO: 17]; GNDCLGX18WSACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 18]; GNDCLGFWSACNPKNDKCCANLVCSSKHKWCRAX17L [SEQ ID NO: 19]; GNDCLGFWSACNPKNDKCCANLVCSSRHKWCKAX17L [SEQ ID NO: 20]; GNDCLGFWSACNPKNDKCCANLVCSSKHRWCKAX17L [SEQ ID NO: 21]; GNDCLGFWSACNPKNDKCCANLVCSSKHX22WCKAX17L [SEQ ID NO: 22]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX19CKAX17L [SEQ ID NO: 23]; GNDCLGX18WSACNPKNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 24]; GNDCLGX19WSACNPKNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 25]; GNDCLGFWX20ACNPKNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 26];GNDCLGFWSACNPRNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 27]; GNDCLGFWSACNPKNDKCCANLVCSKKHKX18CKAX17L [SEQ ID NO: 28]; GNDCLGFWSACNPKNDKCCANLVCSSRHKX18CKAX17L [SEQ ID NO: 29]; GNDCLGFWSACNPKNDKCCANLVCSSKHRX18CKAX17L [SEQ ID NO: 30]; GNDCLGFWSACNPKNDKCCANLVCSSKHX22X18CKAX17L [SEQ ID NO: 31]; GNDCLGFWSACNPKNDKCCANLVCSSKHX21X18CKAX17L [SEQ ID NO: 32]; and GNDCLGX19WSACNPKNDKCCANLVCSKKHKWCKAX17L [SEQ ID NO: 33]; wherein: X17 is Orn; X18 is Bpa; X19 is Bip; X20 is hS; X21 is Dab; and X22 is hR.

[0023] In some embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence represented by any one of SEQ ID NOs: 2-33 and 51-54: GNDCLGAWSACNPKNDKCCANLVCSSKHX21WCKAX17L [SEQ ID NO: 51]; GNDCLGX19WSACNPKNDKCCANAVCSSKHX21WCKAX17L [SEQ ID NO: 52]; GNDCLGX19WSACNPKNDKCCANLVCSSKHX21ACKAX17L [SEQ ID NO: 53]; and GNDCLGX19WSACNPKNDKCCANAVCSSKHX21ACKAX17L [SEQ ID NO: 54], wherein: X17 is Orn; X19 is Bip; and X21 is Dab.

[0024] In some embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence represented by any one of SEQ ID NOs: 2-11, especially an amino acid sequence represented by SEQ ID NO: 9. In some embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence represented by any one of SEQ ID NOs: 2-11, 52 and 53.

[0025] In particular embodiments, the six cysteine residues in the molecule are bonded in pairs to form three disulfide bonds; especially wherein the disulfide bonds are formed between the side chains of Cys 1 and Cys 16, Cys 8 and Cys 21, and Cys 15 and Cys 28 (numbered in accordance with the amino acid sequence of Formula I).

[0026] In some embodiments, the molecule comprises a C-terminal amide.

[0027] In another aspect, there is provided a molecule comprising an amino acid sequence represented by Formula VII: X23LX1X2X3X4AX24NPX5NDKX25X26ANLVX27SX6X7HX8X9X28 (VII) wherein: X1 to X9 are as defined for Formula IV; X23 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X26; X24 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X27; X25 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X28; X26 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X23; X27 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X24; X28 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X25; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1: NDCLGFWSACNPKNDKCCANLVCSSKHKWCKGKL [SEQ ID NO: 1].

[0028] In some embodiments, the covalent cross-link between X23 and X26, X24 and X27 and X25 and X28 are independently selected from the group consisting of a disulfide bond, a diselenide bond, a lanthionine bridge, an amide bond, an ester linkage, a thioester linkage, a carbamoyl linkage, an alkyl linkage, an alkenyl linkage, an ether linkage, a thioether linkage, an amine linkage and a thioamide linkage. In particular embodiments, X23 to X28 are independently selected from the group consisting of C, K, R, D, E, penicillamine, selenocysteine, diaminopropionic acid, mercaptoproline and modified forms thereof.

[0029] Also provided herein is a composition comprising, consisting or consisting essentially of a molecule of the present disclosure and a pharmaceutically acceptable excipient.

[0030] In a further aspect, there is provided a molecule of the present disclosure for use in therapy.

[0031] In yet another aspect, there is provided a method of treating or at least partially inhibiting the development of a condition in which inhibiting Nav1.1 and / or Nav1.7 activity is associated with effective treatment or inhibition of the condition, comprising administering an effective amount of the molecule of the present disclosure.

[0032] In some embodiments, the condition is pain, especially wherein the pain is selected from the group consisting of inflammatory pain, visceral pain, abdominal pain and nociceptive pain. In particular embodiments, the pain is chronic pain.

[0033] In specific embodiments, the pain is visceral pain or abdominal pain, preferably abdominal pain. In some embodiments, the pain is abdominal pain, endometrial pain or bladder pain. In some embodiments, the pain is lower abdominal or pelvic pain. In some embodiments, the pain is associated with irritable bowel syndrome, inflammatory bowel disease, gastrointestinal inflammation, or a gastric motility disorder, such as gastroparesis, functional dyspepsia, cannabis hyperemesis syndrome, chronic intestinal pseudo-obstruction or colonic inertia. In some embodiments, the pain is associated with endometriosis or a urinary tract infection. Preferably, the molecule does not have a substantial effect on gastric motility.

[0034] In some embodiments, the pain is migraine pain.

[0035] In some embodiments, the condition is anxiety.

[0036] Another aspect of the present disclosure provides a method of treating or at least partially inhibiting the development of pain in a subject, comprising administering an effective amount of the molecule of the present disclosure to the subject.

[0037] In particular embodiments, the pain is chronic pain.

[0038] In some embodiments, the pain is selected from the group consisting of inflammatory pain, mechanical pain, visceral pain, abdominal pain and nociceptive pain, especially visceral pain or abdominal pain. In some embodiments, the pain is abdominal pain, endometrial pain or bladder pain. In specific embodiments, the pain is abdominal pain. In some embodiments, the pain is lower abdominal pain or pelvic pain.

[0039] The pain may be associated with a number of conditions, such as irritable bowel syndrome, inflammatory bowel disease, gastrointestinal inflammation or a gastric motility disorder, such as gastroparesis, functional dyspepsia, cannabis hyperemesis syndrome, chronic intestinal pseudo-obstruction or colonic inertia. In some embodiments, the pain is associated with endometriosis or a urinary tract infection.

[0040] In some embodiments, the pain is migraine pain.

[0041] In a further aspect, there is provided a method of antagonising Nav1.1 and / or Nav1.7, comprising contacting Nav1.1 and / or Nav1.7 with a molecule of the present disclosure.

[0042] Also encompassed herein is the use of a molecule of the present disclosure as an analgesic.

[0043] The molecule of the present disclosure may also be used for detecting the binding of a candidate agent to Nav1.1 and / or Nav1.7 and in a method of identifying an agent that binds to Nav1.1 and / or Nav1.7, the method comprising: contacting a preparation with a candidate agent and a molecule of the present disclosure, wherein the preparation comprises a polypeptide comprising an amino acid sequence corresponding to Nav1.1 and / or Nav1.7 or a fragment thereof; and detecting a change in the binding of the molecule of the present disclosure to Nav1.1 and / or Nav1.7 or a fragment thereof relative to the binding of the molecule in the absence of the candidate agent, wherein the change indicates that the candidate agent binds to Nav1.1 and / or Nav1.7.

[0044] In a still further aspect, there is provided a method of identifying an agent for the treatment of abdominal pain, the method comprising: providing a candidate agent; determining whether the candidate agent has a voltage-gated sodium channel inhibitory profile, wherein the inhibitory profile is characterised by an IC50 of 100 nM or less for Nav1.1 and Nav1.7, and an IC50 for Nav1.1 at least two-fold lower than the IC50 for Nav1.6; and identifying the candidate agent as an agent for the treatment of abdominal pain.

[0045] In some embodiments, the candidate agent comprises, consists or consists essentially of an amino acid sequence that is distinguished from the amino acid sequence of SEQ ID NO: 1 by at least one amino acid modification: NDCLGFWSACNPKNDKCCANLVCSSKHKWCKGKL [SEQ ID NO: 1].

[0046] The amino acid modification(s) may be selected from an amino acid substitution, an amino acid addition and an amino acid deletion.

[0047] In another aspect, there is provided a method of treating or at least partially inhibiting the development of abdominal pain in a subject, comprising administering to the subject an effective amount of a molecule having a voltage-gated sodium channel inhibitory profile characterised by an IC50 of 100 nM or less for Nav1.1 and Nav1.7, and an IC50 for Nav1.1 at least two-fold lower than the IC50 for Nav1.6. In some embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence that is distinguished from the amino acid sequence of SEQ ID NO: 1 by at least one amino acid modification.

[0048] A further aspect provides an abdominal pain analgesic comprising a molecule having a voltage-gated sodium channel inhibitory profile characterised by an IC50of 100 nM or less for Nav1.1 and Nav1.7, and an IC50 for Nav1.1 at least two-fold lower than the IC50 for Nav1.6. In some embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence that is distinguished from the amino acid sequence of SEQ ID NO: 1 by at least one amino acid modification. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a series of images from molecular dynamics simulations of the complex formed between peptide M6-NH2 (G-1, F6Bip, K28Dab, G32A, K33Orn, C-terminal amidation) and the domain II voltage sensor (VSD2) of the voltage-gated sodium channels NaV1.1, NaV1.6 and NaV1.7. Figure 1A presents the three-dimensional structure of M6-NH2. Figure 1B shows that the Bip6 side chain of the peptide is close to channel residue 813, which is hydrophobic in Nav1.7 (Phe813) and Nav1.1 (Gly813) but not in Nav1.6 (Ser813). Figure 1C shows that the Dab28 side chain of the peptide is close to channel residue 760, which is negatively charged for both NaV1.1 (Asp760) and NaV1.7 (Glu760) but not NaV1.6 (His764). Figure 1D shows that the Orn33 side chain of the peptide is close to the side chain of channel residue Glu818 in NaV1.1 and NaV1.7. For NaV1.6, Orn33 does not interact with this residue in VSD2 because of a slight shift in binding mode.

[0050] Figure 2 is a cross sectional image taken perpendicular to the membrane bilayer showing the orientation of peptide M6-NH2 relative to the domain II voltage sensor (VSD2) of the human Nav1.7 channel according to molecular dynamics simulations. The peptide sits near the extracellular surface of the membrane, with the hydrophobic side chain of residue Bip6 anchoring it to the bilayer via interactions with membrane phospholipids. The N- and C-termini of M6-NH2 and VSD2 are labelled ‘N’ and ‘C’ respectively, and the four transmembrane helices of VSD2 are labelled 'S1' to 'S4'. The grey box indicates the boundaries of the membrane bilayer.

[0051] Figure 3 is a graph showing concentration-response curves for inhibition of NaV1.1, NaV1.4, NaV1.5, NaV1.6 and NaV1.7 by M6-NH2(i.e., M4 F6Bip K28Dab). Peak currents (I) were normalised against maximum peak currents in the negative control (Ipeak) and plotted as I / Ipeak (%). IC50 values were obtained by fitting a Hill equation to the data using Prism version 8. Data points are mean ± SEM (N = 5).

[0052] Figure 4 is a series of graphs showing the effect of in vivo intra-colonic administration (100 μL) of 1000 nM M6-NH2 on the visceromotor response (VMR) to colorectal distension (CRD) in mice with chronic visceral hypersensitivity (CVH). Figure 4A presents the VMR to CRD relative to the individual colonic distension pressures of mice treated with 1000 nM M6-NH2 compared to vehicle; Figure 4B compares the total area under the curve (AUC) of the VMR to CRD for mice treated with 1000 nM M6-NH2 to mice treated with vehicle; and Figure 4C compares the VMR to CRD for mice treated with 1000 nM M6-NH2 at pressures of 20-40 mmHg (non-noxious pressures) and 50-80 mmHg(noxious pressures). The data show that 1000 nM M6-NH2 significantly inhibits the VMR to CRD in CVH mice, particularly at noxious distension pressures.

[0053] Figure 5 is a series of graphs showing the effect of in vivo intra-colonic administration (100 μL) of a lower dose of 100 nM M6-NH2 on the visceromotor response (VMR) to colorectal distension (CRD) in mice with chronic visceral hypersensitivity (CVH). Figure 5A presents the VMR to CRD relative to individual colonic distension pressures of mice treated with 100 nM M6-NH2 compared to vehicle. Figure 5B compares the total area under the curve (AUC) of the VMR to CRD for each mouse treated with 100 nM M6-NH2 to mice treated with vehicle. Figure 5C compares the VMR to CRD for mice treated with 100 nM M6-NH2 to vehicle at pressures of 20–40 mmHg (non-noxious pressures) and 50–80 mmHg (noxious pressures). The data show that, as opposed to a dose of 1000 nM, a dose of 100 nM M6-NH2 does not significantly inhibit the VMR to CRD in CVH mice.

[0054] Figure 6 is a series of graphs showing no effect of in vivo intra-colonic administration (100 μL) of either 100 nM (left) or 1000 nM (right) M6-NH2 on colonic compliance in chronic visceral hypersensitivity (CVH) mice.

[0055] Figure 7 is a series of graphs showing the effect of ex vivo intra-luminal administration of 100 and 1000 nM M6-NH2 on splanchnic (left) and pelvic (right) colonic afferents in chronic visceral hypersensitivity (CVH) mice. 100 nM M6-NH2 does not inhibit either splanchnic or pelvic afferents. In contrast, 1000 nM of M6-NH2 significantly reduces splanchnic or pelvic afferent firing to distension.

[0056] Figure 8 is a series of graphs showing the overall effects of ex vivo intra- luminal administration of M6-NH2 on splanchnic and pelvic colonic afferents from CVH mice. Data shows a greater inhibition (expressed as ‘percentage of baseline response’ and ‘change from baseline’) with M6-NH2.

[0057] Figure 9 is a series of graphs showing the overall effects of ex vivo intra- luminal administration of M6-NH2 on colonic motility from mice. Overall, neither 100 nM nor 1000 nM M6-NH2 significantly altered colonic motility.

[0058] Figure 10 is a series of graphs showing the stability of the Hs1a analogues, M5-NH2 and M6-NH2, compared to wild-type Hs1a and linaclotide in simulated intestinal fluid (SIF). Figure 10A displays the stability of various derivatives of wild-type Hs1a. Figure 10B displays the stability of M5-NH2 and M6-NH2 compared to linaclotide and wild-type Hs1a.

[0059] Figure 11 is a graph showing concentration-response curves for inhibition of NaV1.1, NaV1.6 and NaV1.7 by M6 Bip7A. Peak currents (I) were normalised against negative control maximum peak currents (Ipeak) and plotted as I / Ipeak (%). IC50 values wereobtained by fitting a Hill equation to the data using Prism version 8. Data points are mean ± SEM (N = 5).

[0060] Figure 12 is a graph showing concentration-response curves for inhibition of NaV1.1, NaV1.6 and NaV1.7 by M6 L22A. Peak currents (I) were normalised against negative control maximum peak currents (Ipeak) and plotted as I / Ipeak (%). IC50 values were obtained by fitting a Hill equation to the data using Prism version 8. Data points are mean ± SEM (N = 3).

[0061] Figure 13 is a graph showing concentration-response curves for inhibition of NaV1.1 NaV1.6 and NaV1.7 by M6 W30A. Peak currents (I) were normalised against negative control maximum peak currents (Ipeak) and plotted as I / Ipeak (%). IC50 values were obtained by fitting a Hill equation to the data using Prism version 8. Data points are mean ± SEM (N = 6).

[0062] Figure 14 is a graph showing relative expression of mRNA encoding the alpha-subunit of the voltage-gated sodium channels Nav1.1–Nav1.9 in colon sub-serosal traced thoracolumbar (T10-L1) dorsal root ganglion (DRG) neurons from healthy mice. Tubb3 is used as a positive neuron marker and Gfap is used to exclude neurons with glial cell contamination. n=24 colon DRG neurons identified by sub-serosal traced in healthy mice.

[0063] Figure 15 is a series of graphs showing relative expression of mRNA encoding voltage-gated sodium channel beta subunits (i.e., NaV1b, NaV2b, NaV3b and NaV4b) in sub-serosal traced colon-innervating thoracolumbar (T10-L1) and lumbosacral (L6-S1) DRG neurons from healthy mice.

[0064] Figure 16 is a graph showing the percentage of cells expressing mRNA encoding the alpha and beta subunits of the voltage-gated sodium channels Nav1.1–Nav1.9 in colon mucosal traced lumbosacral (L6-S1) DRG neurons from healthy mice. n.d = not detected.

[0065] Figure 17 is a series of graphs showing relative expression of mRNA encoding the alpha-subunit of the voltage-gated sodium channels Nav1.1–Nav1.9 in whole thoracolumbar (TL) (Figure 17A) and lumbosacral (LS) (Figure 17B) DRG from healthy and chronic visceral hypersensitivity (CVH) mice.

[0066] Figure 18 is a graph showing single-cell expression of the alpha-subunits of the voltage-gated sodium channels Nav1.1–Nav1.9 in colon sub-serosal traced thoracolumbar (T10-L1) DRG neurons from healthy (n=24 neurons) and CVH (n=30 neurons) mice.

[0067] Figure 19 is a graph showing relative expression of mRNA encoding the alpha-subunit of the voltage-gated sodium channels Nav1.1–Nav1.9 in the colonic mucosa of healthy and chronic visceral hypersensitivity (CVH) mice. bdl = below detection limit.

[0068] Figure 20 is a graph showing relative expression of mRNA encoding the alpha-subunit of the voltage-gated sodium channels Nav1.1–Nav1.9 in whole thoracolumbar (T9, T10, T11, T12, L1) DRG from healthy humans. Nav1.1-Nav1.9 mRNA expression in human TL (T9, T10, T11, T12, L1) DRG was measured in 4 healthy donors. Error bars are mean ± SEM.

[0069] Figure 21 is a graph showing the expression of NaV1.1-NaV1.9 in healthy colonic mucosal biopsies from 3 subjects. DETAILED DESCRIPTION 1. Definitions

[0070] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure, preferred methods and materials are described. For the purposes of the present disclosure, the following terms are defined below.

[0071] The articles “a” and “an” are used herein to refer to one or to more than one (i.e. to at least one) of the grammatical object of the article. By way of example, “an element” means one element or more than one element.

[0072] The term “aberrant activity” refers to activity deviating from normal activity. The term “hyperactivity” refers to activity higher than normal activity.

[0073] By “about” is meant a quantity, level, value, number, frequency, percentage, dimension, size, amount, weight or length that varies by as much 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 % to a reference quantity, level, value, number, frequency, percentage, dimension, size, amount, weight or length.

[0074] The terms “administration concurrently” or “administering concurrently” or “co-administering” and the like refer to the administration of a single composition containing two or more agents, or the administration of each agent as separate compositions and / or delivered by separate routes either contemporaneously or simultaneously or sequentially within a short enough period of time that the effective result is equivalent to that obtained when all such agents are administered as a single composition. By “simultaneously” is meant that the agents are administered at substantially the same time, and desirably together in the same composition. By “contemporaneously” it is meant that the agents are administered closely in time, e.g.,one agent is administered within from about one minute to within about one day before or after another. Any contemporaneous time is useful. However, it will often be the case that when not administered simultaneously, the agents will be administered within about one minute to within about eight hours and suitably within less than about one to about four hours. When administered contemporaneously, the agents are suitably administered at the same site on the subject. The term “same site” includes the exact location, but can be within about 0.5 to about 15 centimetres, preferably from within about 0.5 to about 5 centimetres. The term “separately” as used herein means that the agents are administered at an interval, for example at an interval of about a day to several weeks or months. The agents may be administered in either order. The term “sequentially” as used herein means that the agents are administered in sequence, for example at an interval or intervals of minutes, hours, days or weeks. If appropriate the agents may be administered in a regular repeating cycle.

[0075] The term “agent” includes a compound that induces a desired pharmacological and / or physiological effect. The term also encompasses pharmaceutically acceptable and pharmacologically active ingredients of those compounds specifically mentioned herein including but not limited to salts, esters, amides, prodrugs, active metabolites, analogues and the like. When the above term is used, then it is to be understood that this includes the active agent per se as well as pharmaceutically acceptable, pharmacologically active salts, esters, amides, prodrugs, metabolites, analogues, etc. The term “agent” is not to be construed narrowly but extends to small molecules, proteinaceous molecules such as peptides, polypeptides and proteins as well as compositions comprising them and genetic molecules such as RNA, DNA and mimetics and chemical analogues thereof as well as cellular agents. The term "candidate agent" refers to an agent that is to be tested for its ability to bind or interact with a target, such as a voltage-gated sodium channel, including Nav1.1 and / or Nav1.7. Preferably, the candidate agent shows selectivity for binding or interaction with one or more voltage-gated sodium channels, such as Nav1.1 and / or Nav1.7, over one or more other voltage-gated sodium channels, such as Nav1.6.

[0076] Amino acid residues are referred to herein interchangeably using their full name or the one or three letter codes standard in the art. Abbreviations used for unnatural or modified amino acid residues or derivatives thereof are defined herein where appropriate.

[0077] Amino acid residues are defined herein on the basis of the side chain classification in some instances at physiological pH or within one or two pH units thereof (e.g. histidine). Families of amino acid residues having similar side chains can be generally sub-classified, without limiting the classification of a particular amino acid, as follows:TABLE 1 AMINO ACID SUB-CLASSIFICATION Sub-Classes Amino Acids A idi A ti id d Gl t i id e

[0078] As used herein, the term and / or refers to and encompasses any and all possible combinations of one or more of the associated listed items, as well as the lack of combinations when interpreted in the alternative (or).

[0079] The term “antagonist” and grammatical equivalents thereof as used herein refers to a molecule that partially or completely inhibits, by any mechanism, an effect of another molecule such as an enzyme, receptor or intracellular mediator. In the context of the present disclosure, the term “antagonist” refers to a molecule that is a direct antagonist that binds to or otherwise interacts with a voltage-gated sodium channel, especially Nav1.1 and / or Nav1.7. Antagonism of Nav1.1 and / or Nav1.7 may inhibit or reduce Nav1.1 and / or Nav1.7 activity and / or function, including any one or more of transport of sodium ions across a cellular membrane, activation of the channel, movement of the voltage sensor into the open channel conformation, propagation of an action potential and / or cellular depolarisation. By way of example, an antagonist can cause a decrease of about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 100% in an activity, or function relative to the activity or function of Nav1.1 and / or Nav1.7 in the absence of the antagonist.

[0080] The term “any amino acid residue” is used herein to refer to any of the 20 naturally occurring amino acid residues and modified versions thereof, includingresidues with modified side chains, N-methyl amino acids, α-methyl amino acids, residues with acetylated N-termini, beta amino acids, N-substituted amino acids and the like.

[0081] The term “biologically active fragment” refers to a fragment that has one or more amino acid residues deleted from the N and / or C-terminus of a protein while still retaining one or more of its functional activities (e.g. ligand binding, ion transport, propagation of an action potential and / or cellular depolarisation, etc.).

[0082] Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. Thus, the use of the term “comprising” and the like indicates that the listed integers are required or mandatory, but that other integers are optional and may or may not be present. By “consisting of” is meant including, and limited to, whatever follows the phrase “consisting of”. Thus, the phrase “consisting of” indicates that the listed elements are required or mandatory, and that no other elements may be present. By “consisting essentially of” is meant including any elements listed after the phrase, and limited to other elements that do not interfere with or contribute to the activity or action specified for the listed elements. Thus, the phrase “consisting essentially of” indicates that the listed elements are required or mandatory, but that other elements are optional and may or may not be present depending upon whether or not they affect the activity or action of the listed elements. In specific embodiments, the term "consisting essentially of", in the context of a specific amino acid sequence disclosed herein, includes within its scope about 1 to about 50 optional amino acids (and all integer optional amino acids in between) upstream of the specific amino acid sequence and / or about 1 to about 50 optional amino acids (and all integer optional amino acids in between) downstream of the specific amino acid sequence.

[0083] By “derivative” is meant a molecule, such as a polypeptide, that has been derived from the basic molecule by modification, for example by conjugation or complexing with other chemical components or by post-translational modification techniques as would be understood in the art. The term “derivative” also includes within its scope alterations that have been made to a parent molecule including additions or deletions that provide for functionally equivalent molecules.

[0084] As used herein, the term “dosage unit form” refers to physically discrete units suited as unitary dosages for the subject to be treated, each unit containing a predetermined quantity of active material calculated to produce the desired therapeutic effect in association with the required pharmaceutically acceptable vehicle.

[0085] By “effective amount”, in the context of treating or inhibiting the development of a condition is meant the administration of an amount of an agent orcomposition to an individual in need of such treatment or prophylaxis, either in a single dose or as part of a series, that is effective for the prevention of incurring a symptom, holding in check such symptoms, and / or treating existing symptoms, of that condition. The effective amount will vary depending upon the health and physical condition of the individual to be treated, the taxonomic group of individual to be treated, the formulation of the composition, the assessment of the medical situation, and other relevant factors. It is expected that the amount will fall in a relatively broad range that can be determined through routine trials.

[0086] As used herein, the phrase “inhibit the development of” refers to a prophylactic treatment which increases the resistance of a subject to developing the disease, disorder or condition or, in other words, decreases the likelihood that the subject will develop the disease, disorder or condition as well as a treatment after the disease, disorder or condition has begun in order to reduce or eliminate it altogether or prevent it from becoming worse. This phrase also includes within its scope preventing the disease, disorder or condition from occurring in a subject which may be predisposed to the disease, disorder or condition but has not yet been diagnosed as having it.

[0087] The term “inhibitor” as used herein refers to an agent that decreases or at least partially inhibits at least one function or biological activity of a target molecule. For example, an Nav1.1 and / or Nav1.7 inhibitor is an agent that at least partially inhibits at least one function or biological activity of Nav1.1 and / or Nav1.7, such as any one or more of transport of sodium ions across a cellular membrane, activation of the channel, movement of the voltage sensor into the open channel conformation, propagation of an action potential and / or cellular depolarisation.

[0088] As used herein, the term “isolated” refers to material that is substantially or essentially free from components that normally accompany it in its native state. For example, an “isolated molecule” refers to in vitro isolation and / or purification of a molecule from its natural cellular environment and from association with other components of the cell. “Substantially free” means that a preparation of molecule is at least 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99% pure. In a preferred embodiment, the preparation of molecule has less than about 30, 25, 20, 15, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1% (by dry weight), of molecules that are not the subject of the present disclosure. When the molecule is recombinantly produced, it is also desirably substantially free of culture medium, i.e., culture medium represents less than about 20, 15, 10, 5, 4, 3, 2 or 1% of the volume of the preparation. The present disclosure includes isolated or purified preparations of at least 0.01, 0.1, 1.0, and 10 milligrams in dry weight.

[0089] As used herein, the term "Nav1.7" refers to any one of more of the subunits of Nav1.7 (e.g. at least one of the α, β1, β2, β3 and / or β4 subunits) unless expressly stated. Similarly, the term "Nav1.1" refers to any one or more of the subunits of Nav1.1 (e.g. at least one of the α, β1, β2, β3 and / or β4 subunits) unless otherwise specified.

[0090] By “pharmaceutically acceptable carrier” is meant a pharmaceutical vehicle comprised of a material that is not biologically or otherwise undesirable, i.e., the material may be administered to a subject along with the selected active agent without causing any or a substantial adverse reaction. Carriers may include excipients and other additives such as diluents, fillers, detergents, colouring agents, wetting or emulsifying agents, pH buffering agents, preservatives and the like. Similarly, a "pharmaceutically acceptable excipient" is a pharmaceutical excipient comprised of a material that is not biologically or otherwise undesirable and a “pharmacologically acceptable” salt, ester, amide, prodrug or derivative of a compound as provided herein is a salt, ester, amide, prodrug or derivative that this not biologically or otherwise undesirable.

[0091] As used herein, the terms “polypeptide”, “proteinaceous molecule”, “peptide” and “protein” are used interchangeably to refer to a polymer of amino acid residues and to variants and synthetic analogues of the same. The term “proteinaceous” as used in for example "proteinaceous molecule" refers to the presence of at least a part of the molecule that resembles or is a protein, wherein "protein" is to be understood to include a chain of amino-acid residues at least two residues long, thus including a peptide, a polypeptide and a protein and an assembly of proteins or protein domains. These terms apply to amino acid polymers in which one or more amino acid residues is a synthetic non- naturally-occurring amino acid, such as a chemical analogue of a corresponding naturally- occurring amino acid, as well as to naturally-occurring amino acid polymers. These terms do not exclude modifications, for example, glycosylations, acetylations, phosphorylations, attachment of lipid or protecting / stabilising components and the like. Soluble forms of the disclosed proteinaceous molecules are particularly useful. Included within the definition are, for example, polypeptides containing one or more analogues of an amino acid including, for example, unnatural amino acids, polypeptides with substituted linkages and polypeptides with PEG groups and lipophilic components.

[0092] The terms “reduce”, “inhibit”, “decrease”, “prevent”, and grammatical equivalents when used in reference to the level of a substance and / or phenomenon in a first sample relative to a second sample, mean that the quantity of substance and / or phenomenon in the first sample is lower than in the second sample by any amount that is statistically significant using any art-accepted statistical method of analysis. When these terms are used to refer to the action of a molecule or agent, the first sample may be a sample in the presence of the molecule or agent and the second sample may be acomparative sample without the molecule or agent. In one embodiment, the reduction may be determined subjectively, for example when a patient refers to their subjective perception of disease symptoms, such as pain. In another embodiment, the reduction may be determined objectively, for example using the Chronic Pain Behavioural Pain Scale. In another embodiment, the quantity of substance and / or phenomenon in the first sample is at least 10% lower than the quantity of the same substance and / or phenomenon in a second sample. In another embodiment, the quantity of the substance and / or phenomenon in the first sample is at least 25% lower than the quantity of the same substance and / or phenomenon in a second sample. In yet another embodiment, the quantity of the substance and / or phenomenon in the first sample is at least 50% lower than the quantity of the same substance and / or phenomenon in a second sample. In a further embodiment, the quantity of the substance and / or phenomenon in the first sample is at least 75% lower than the quantity of the same substance and / or phenomenon in a second sample. In yet another embodiment, the quantity of the substance and / or phenomenon in the first sample is at least 90% lower than the quantity of the same substance and / or phenomenon in a second sample. Alternatively, a difference may be expressed as an “n-fold” difference.

[0093] As used herein, the terms “salts” and “prodrugs” include any pharmaceutically acceptable salt, ester, hydrate or any other compound which, upon administration to the recipient, is capable of providing (directly or indirectly) a molecule of the present disclosure, or an active metabolite or residue thereof. The term “pharmaceutically acceptable salts” refers without limitation to derivatives of the disclosed compounds wherein the parent compound is modified by converting an existing acid or base component to its salt form (e.g. by reacting the free base group with a suitable organic acid). Examples of pharmaceutically acceptable salts include, but are not limited to, mineral or organic acid salts of basic residues such as amines; alkali or organic salts of acidic residues such as carboxylic acids; and the like. Representative acid addition salts include acetate, adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, fumarate, glucoheptonate, glycerophosphate, hemisulfate, heptonate, hexanoate, hydrobromide, hydrochloride, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, toluenesulfonate, undecanoate and valerate salts, and the like. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like, as well as nontoxic ammonium, quaternary ammonium, and amine cations, including, but not limited to ammonium, tetramethylammonium, tetraethylammonium,methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine, and the like. The pharmaceutically acceptable salts of the present disclosure include the conventional non- toxic salts of the parent compound formed, for example, from non-toxic inorganic or organic acids. The pharmaceutically acceptable salt can be synthesised from the parent compound which contains a basic or acidic component by conventional chemical methods. Generally, such salts can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid in water or in an organic solvent, or in a mixture of the two; generally, nonaqueous media like ether, ethyl acetate, ethanol, isopropanol, or acetonitrile are preferred. Lists of suitable salts are found in, for example, Remington: The Science and Practice of Pharmacy, Adeboye Adejare and Joseph Remington (Ed), Academic Press, London, 23rdEdition, 2021; Stahl and Wermuth (2002) Pharmaceutical Salts: Properties, Selection, and Use, Wiley-VCH; and Berge et al. (1977) Journal of Pharmaceutical Science, 66: 1-19, each of which is incorporated herein by reference in its entirety.

[0094] The terms "selective" and "selectivity" as used herein refer to agents or molecules that modulate (e.g. inhibit) an ion channel subtype of interest without displaying substantial modulation of one or more other ion channel subtypes. Accordingly, an agent that is selective for Nav1.1 modulates Nav1.1 to a greater extent, for example greater than about 2-fold, 5-fold, 10-fold, 20-fold, 50-fold, 100-fold or greater than about 500-fold, than one or more other Navsubtypes (e.g. Nav1.2-1.6, Nav1.8 and Nav1.9), and an agent that is selective for Nav1.7 modulates Nav1.7 to a greater extent, for example greater than about 2-fold, 5-fold, 10-fold, 20-fold, 50-fold, 100-fold or greater than about 500-fold than one or more other Nav subtypes (e.g. Nav1.2-1.6, Nav1.8 and Nav1.9).

[0095] The term “sequence identity” as used herein refers to the extent that sequences are identical on an amino acid-by-amino acid basis over a window of comparison. Thus, a “percentage of sequence identity” is calculated by comparing two optimally aligned sequences over the window of comparison, determining the number of positions at which the identical amino acid residue occurs in both sequences to yield the number of matched positions, dividing the number of matched positions by the total number of positions in the window of comparison (i.e. the window size), and multiplying the result by 100 to yield the percentage of sequence identity.

[0096] “Similarity” refers to the percentage number of amino acids that are identical or constitute conservative substitutions as described in Tables 1 and 2 herein. Similarity may be determined using sequence comparison programs such as GAP (Deveraux et al.1984, Nucleic Acids Research 12: 387-395). In this way, sequences of a similar or substantially different length to those cited herein might be compared byinsertion of gaps into the alignment, such gaps being determined, for example, by the comparison algorithm used by GAP.

[0097] Terms used to describe sequence relationships between two or more polypeptides include “reference sequence,” “comparison window”, “sequence identity,” “percentage of sequence identity” and “substantial identity”. A “reference sequence” is at least 8 but frequently 28 to 35 amino acid residues in length. As two amino acid sequences may each comprise (1) a sequence (i.e. only a portion of the complete molecule) that is similar between the two molecules, and (2) a sequence that is divergent between the two molecules, sequence comparisons between two (or more) molecules are typically performed by comparing sequences of the two molecules over a “comparison window” to identify and compare local regions of sequence similarity. A “comparison window” refers to a conceptual segment of at least 6 contiguous positions in which a sequence is compared to a reference sequence of the same number of contiguous positions after the two sequences are optimally aligned. The comparison window may comprise additions or deletions (i.e. gaps) of about 20% or less as compared to the reference sequence (which does not comprise additions or deletions) for optimal alignment of the two sequences. Optimal alignment of sequences for aligning a comparison window may be conducted by computerised implementations of algorithms (GAP, BESTFIT, FASTA, and TFASTA in the Wisconsin Genetics Software Package Release 7.0, Genetics Computer Group, 575 Science Drive Madison, WI, USA) or by inspection and the best alignment (i.e. resulting in the highest percentage homology over the comparison window) generated by any of the various methods selected. Reference also may be made to the BLAST family of programs as for example disclosed by Altschul et al. (1997) Nucl. Acids Res. 25: 3389. A detailed discussion of sequence analysis can be found in Unit 19.3 of Ausubel et al. (1998) Current Protocols in Molecular Biology, John Wiley & Sons Inc, Chapter 15; Lambert et al. (2003) Current Genomics, 4:131-146; and Bawano et al. (2017) Bioinformatics, Volume 1: Data, Sequence Analysis and Evolution (Methods in Molecular Biology (1525)), Humana Press, pages 167-189.

[0098] The term “subject” as used herein refers to a vertebrate subject, particularly a mammalian or avian (bird) subject, for whom therapy or prophylaxis is desired. Suitable subjects include, but are not limited to, primates; avians (birds); livestock animals such as sheep, cows, horses, deer, donkeys and pigs; laboratory test animals such as rabbits, mice, rats, guinea pigs and hamsters; companion animals such as cats and dogs; and captive wild animals such as foxes, deer and dingoes. In particular embodiments, the subject is a primate, suitably a human. However, it will be understood that the aforementioned terms do not imply that symptoms are present.

[0099] As used herein, the terms “treatment”, “treating”, and the like, refer to obtaining a desired pharmacologic and / or physiologic effect. The effect may be therapeutic in terms of a partial or complete cure for a disease, disorder or condition and / or adverse effect attributable to the disease, disorder or condition. These terms also cover any treatment of a condition or disease in a subject, particularly in a human, and include: (a) inhibiting the disease or condition, i.e. arresting or slowing its development; or (b) relieving the disease or condition, i.e. causing regression of the disease or condition.

[0100] Each embodiment described herein is to be applied mutatis mutandis to each and every embodiment unless specifically stated otherwise. 2. Abbreviations

[0101] The following abbreviations are used throughout the application: PEG = Poly(ethylene glycol) Nle = Norleucine Bpa = 4-Benzoyl-L-phenylalanine Bip = 4,4’-Biphenylalanine hS = Homoserine hR = Homoarginine Dab = Diaminobutyric acid Orn = Ornithine mins = Minutes s = Seconds h = Hours IC50 = Half maximal inhibitory concentration 3. Molecules

[0102] The present disclosure is based, in part on the finding that particular molecules derived from Hs1a inhibit Nav1.1 and Nav1.7. These molecules may have selectivity for inhibition of Nav1.1 and Nav1.7 over other sodium channel subtypes, such as Nav1.6. Based on this finding, the molecules are considered to be useful for treating or at least partially inhibiting the development of a condition in which inhibiting Nav1.1 and / or Nav1.7 activity is associated with effective treatment or inhibition of such condition, non- limiting examples of which include pain, such as inflammatory pain, visceral pain, abdominal pain and nociceptive pain, and anxiety. In some embodiments, the molecule of the present disclosure may have reduced side effects or off-target effects, due at least in part to improved voltage-gated sodium channel selectivity.

[0103] Accordingly, in one aspect, there is provided a molecule (e.g. a proteinaceous molecule or a peptide) comprising, consisting or consisting essentially of an amino acid sequence represented by Formula I: CLX1X2X3X4ACNPX5NDKCCANX29VCSX6X7HX8X9C (I) wherein: X1 is a small amino acid residue or an acidic amino acid residue; X2 is a hydrophobic amino acid residue or a small amino acid residue; X3 is a hydrophobic amino acid residue; X4 is a small amino acid residue; X5 is a basic amino acid residue; X6 is a small amino acid residue or a basic amino acid residue; X7is a basic amino acid residue; X8 is a basic amino acid residue; X9 is any amino acid residue; and X29 is any amino acid residue, wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1: NDCLGFWSACNPKNDKCCANLVCSSKHKWCKGKL [SEQ ID NO: 1].

[0104] In some embodiments: X1 is selected from small amino acid residues including A, S, G, T and modified forms thereof, and acidic amino acid residues including D, E and modified forms thereof; X2 is selected from hydrophobic amino acid residues including M, I, L, V, F, Y, W, Nle and modified forms thereof, including 4-benzoyl-L-phenylalanine (Bpa) and 4,4’- biphenylalanine (Bip), and small amino acid residues including A, S, G, T and modified forms thereof; X3 is selected from hydrophobic amino acid residues including M, I, L, V, F, Y, W, Nle and modified forms thereof; X4 is selected from small amino acid residues including A, S, G, T and modified forms thereof, including homoserine (hS); X5 is selected from basic amino acid residues including R, K and modified forms thereof;X6 is selected from small amino acid residues including A, S, G, T and modified forms thereof, and basic amino acid residues including R, K and modified forms thereof; X7 is selected from basic amino acid residues including R, K and modified forms thereof; X8 is selected from basic amino acid residues including R, K and modified forms thereof, including homoarginine (hR), and diaminobutyric acid (Dab); X9 is selected from hydrophobic amino acid residues including M, I, L, V, F, Y, W, Nle and modified forms thereof, including Bpa and Bip, basic amino acid residues including R, K and modified forms thereof, acidic amino acid residues including D, E and modified forms thereof, amide containing amino acid residues, including Q, N and modified forms thereof, P and modified forms thereof, and small amino acid residues including A, S, G, T and modified forms thereof; and / or X29 is selected from hydrophobic amino acid residues including M, I, L, V, F, Y, W, Nle and modified forms thereof, basic amino acid residues including R, K and modified forms thereof, acidic amino acid residues including D, E and modified forms thereof, amide containing amino acid residues, including Q, N and modified forms thereof, P and modified forms thereof, and small amino acid residues including A, S, G, T and modified forms thereof.

[0105] In some embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence represented by Formula IV: CLX1X2X3X4ACNPX5NDKCCANLVCSX6X7HX8X9C (IV) wherein: X1 is a small amino acid residue or an acidic amino acid residue; X2 is a hydrophobic amino acid residue; X3 is a hydrophobic amino acid residue; X4 is a small amino acid residue; X5 is a basic amino acid residue; X6 is a small amino acid residue or a basic amino acid residue; X7 is a basic amino acid residue; X8 is a basic amino acid residue; and X9 is a hydrophobic amino acid residue; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1:NDCLGFWSACNPKNDKCCANLVCSSKHKWCKGKL [SEQ ID NO: 1].

[0106] In some embodiments: X1 is selected from small amino acid residues including A, S, G, T and modified forms thereof, and acidic amino acid residues including D, E and modified forms thereof; X2 is selected from hydrophobic amino acid residues including M, I, L, V, F, Y, W, Nle and modified forms thereof, including 4-benzoyl-L-phenylalanine (Bpa) and 4,4’- biphenylalanine (Bip); X3 is selected from hydrophobic amino acid residues including M, I, L, V, F, Y, W, Nle and modified forms thereof; X4 is selected from small amino acid residues including A, S, G, T and modified forms thereof, including homoserine (hS); X5 is selected from basic amino acid residues including R, K and modified forms thereof; X6 is selected from small amino acid residues including A, S, G, T and modified forms thereof, and basic amino acid residues including R, K and modified forms thereof; X7 is selected from basic amino acid residues including R, K and modified forms thereof; X8 is selected from basic amino acid residues including R, K and modified forms thereof, including homoarginine (hR), and diaminobutyric acid (Dab); and X9 is selected from hydrophobic amino acid residues including M, I, L, V, F, Y, W, Nle and modified forms thereof, including Bpa and Bip.

[0107] In particular embodiments, X1 is selected from A, S, G, T, D, E and modified forms thereof; especially A, S, G, T, D or E; more especially G or E; most especially G. In some embodiments, X1 is selected from small amino acid residues including A, S, G, T and modified forms thereof; especially A, S, G or T; most especially G.

[0108] X2 is, in some embodiments, selected from M, I, L, V, F, Y, W, Nle, Bpa, Bip and modified forms thereof; especially M, I, L, V, F, Y, W, Nle, Bpa or Bip; more especially F or Bip; most especially Bip. In some embodiments, X2 is selected from M, I, L, V, F, Y, W, Nle, Bpa, Bip, A, G, S, T and modified forms thereof; especially M, I, L, V, F, Y, W, Nle, Bpa, Bip, A, G, S or T. In some embodiments, X2 is F, A, Bip or Bpa. In particular embodiments, X2 is F, A or Bip; most especially Bip.

[0109] In some embodiments, X3is selected from M, I, L, V, F, Y, W, Nle and modified forms thereof; especially M, I, L, V, F, Y, W or Nle; more especially W.

[0110] In some embodiments, X4 is selected from A, S, G, T, hS and modified forms thereof; especially A, S, G, T or hS; more especially S or hS; most especially S.

[0111] In some embodiments, X5 is selected from R, K and modified forms thereof; especially R or K; more especially K.

[0112] In exemplary embodiments, X6 is selected from A, S, G, T, R, K and modified forms thereof; especially A, S, G, T, R or K; more especially S or K; most especially S. In alternative embodiments, X6 is selected from small amino acid residues including A, S, G, T and modified forms thereof; especially A, S, G or T; most especially S.

[0113] In some embodiments, X7 is selected from R, K and modified forms thereof; especially R or K; most especially K.

[0114] In particular embodiments, X8 is selected from R, K, hR, Dab and modified forms thereof; especially R, K, hR or Dab; more especially K or Dab; most especially Dab.

[0115] In some embodiments, X9 is selected from M, I, L, V, F, Y, W, Nle, Bpa, Bip and modified forms thereof; especially M, I, L, V, F, Y, W, Nle, Bpa or Bip; more especially W or Bpa; most especially W. In some embodiments, X9is selected from M, I, L, V, F, Y, W, Nle, Bpa, Bip, R, K, D, E, Q, N, P, A, S, G, T and modified forms thereof; such as M, I, L, V, F, Y, W, Nle, Bpa, Bip, R, K, D, E, Q, N, P, A, S, G or T. In some embodiments, X9 is W, A, Bpa or Bip; such as W, A or Bpa; or W or A.

[0116] In some embodiments, X9 is selected from hydrophobic amino acid residues and small amino acid residues. For example, in some embodiments, X9 is selected from M, I, L, V, F, Y, W, Nle, Bpa, Bip, A, S, G, T and modified forms thereof; especially M, I, L, V, F, Y, W, Nle, Bpa, Bip, A, S, G or T; more especially W, A or Bpa; most especially W or A. In some embodiments, X9 is selected from small amino acid residues. For example, in some embodiments, X9 is selected from A, S, G, T and modified forms thereof; especially A, S, G or T. In some embodiments, X9 is A.

[0117] In some embodiments, X29 is selected from M, I, L, V, F, Y, W, Nle, R, K, D, E, Q, N, P, A, S, G, T and modified forms thereof; especially M, I, L, V, F, Y, W, Nle, R, K, D, E, Q, N, P, A, S, G or T. In some embodiments, X29 is selected from hydrophobic amino acid residues and small amino acid residues. For example, in some embodiments, X29 is selected from M, I, L, V, F, Y, W, Nle, A, S, G, T and modified forms thereof; especially M, I, L, V, F, Y, W, Nle, A, S, G or T. In some embodiments, X29 is L or A. In some embodiments, X29 is L. In alternative embodiments, X29 is A.

[0118] In some embodiments, X9 and X29 are A.

[0119] In some embodiments: X1 is A, S, G, T, D or E; X2 is M, I, L, V, F, Y, W, Nle, Bpa, Bip, A, G, S or T; X3 is M, I, L, V, F, Y, W or Nle;X4 is A, S, G, T or hS; X5 is R or K; X6 is A, S, G, T, R or K; X7 is R or K; X8 is R, K, hR or Dab; X9 is M, I, L, V, F, Y, W, Nle, Bpa, Bip, R, K, D, E, Q, N, P, A, S, G or T; and / or X29 is M, I, L, V, F, Y, W, Nle, R, K, D, E, Q, N, P, A, S, G or T.

[0120] In some embodiments: X1 is G or E; X2 is F, A, Bip or Bpa; X3 is W; X4 is S or hS; X5 is K or R; X6 is K or S; X7 is K or R; X8 is K, R, Dab or hR; X9 is W, Bpa, A or Bip; and / or X29 is L or A.

[0121] In specific embodiments: X1 is G; X2 is F, A or Bip; X3is W; X4 is S or hS; X5 is R or K; X6 is S or K; X7 is K; X8is K or Dab; X9 is W, A or Bpa; and / or X29 is L or A.

[0122] In some embodiments: X1 is A, S, G, T, D or E; X2 is M, I, L, V, F, Y, W, Nle, Bpa or Bip; X3 is M, I, L, V, F, Y, W or Nle; X4 is A, S, G, T or hS; X5 is R or K; X6 is A, S, G, T, R or K; X7 is R or K; X8 is R, K, hR or Dab; and / or X9 is M, I, L, V, F, Y, W, Nle, Bpa or Bip.

[0123] In some embodiments: X1 is G or E; X2 is F, Bip or Bpa; X3 is W; X4 is S or hS; X5 is K or R; X6 is K or S; X7 is K or R; X8 is K, R, Dab or hR; and / or X9 is W, Bpa or Bip.

[0124] In specific embodiments: X1is G; X2 is F or Bip; X3 is W; X4 is S or hS; X5 is R or K; X6is S or K; X7 is K; X8 is K or Dab; and / orX9 is W or Bpa.

[0125] In some embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence represented by Formula II: X10X11X12CLX1X2X3X4ACNPX5NDKCCANX29VCSX6X7HX8X9CX13X14X15X16 (II) wherein: X1 to X9 and X29 are as defined for Formula I supra; X10 is absent or is a small amino acid residue; X11 is an amide-containing amino acid residue; X12 is an acidic amino acid residue; X13 is a basic amino acid residue; X14 is a small amino acid residue; X15 is a basic amino acid residue; and X16 is a hydrophobic amino acid residue.

[0126] In some embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence represented by Formula V: X10X11X12CLX1X2X3X4ACNPX5NDKCCANLVCSX6X7HX8X9CX13X14X15X16 (V) wherein: X1 to X9 are as defined for Formula IV supra; X10 is absent or is a small amino acid residue; X11 is an amide-containing amino acid residue; X12is an acidic amino acid residue; X13 is a basic amino acid residue; X14 is a small amino acid residue; X15 is a basic amino acid residue; and X16 is a hydrophobic amino acid residue; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1.

[0127] Suitable embodiments of each of X1 to X9 and X29 are as described supra.

[0128] In some embodiments:X1 to X9 are as defined for Formula IV or X1 to X9 and X29 are as defined for Formula I supra; X10 is absent or is selected from small amino acid residues including A, S, G, T and modified forms thereof; X11 is selected from amide-containing amino acid residues including N, Q and modified forms thereof; X12 is selected from acidic amino acid residues including D, E and modified forms thereof; X13 is selected from basic amino acid residues including R, K and modified forms thereof, including hR; X14 is selected from small amino acid residues including A, S, G, T and modified forms thereof; X15 is selected from basic amino acid residues including R, K and modified forms thereof, including Ornithine (Orn); and X16is selected from hydrophobic amino acid residues including M, I, L, V, F, Y, W, Nle and modified forms thereof.

[0129] In particular embodiments, X10 is absent or is selected from A, S, G, T and modified forms thereof; especially absent or is A, S, G or T; more especially absent or G; most especially G.

[0130] In some embodiments, X11 is selected from N, Q and modified forms thereof; especially N or Q; more especially N.

[0131] In some embodiments, X12 is selected from D, E and modified forms thereof; especially D or E; more especially D.

[0132] In particular embodiments, X13 is selected from R, K, hR and modified forms thereof; especially R, K or hR; more especially K.

[0133] In some embodiments, X14 is selected from A, S, G, T and modified forms thereof; especially A, S, G or T; more especially A or G; most especially A.

[0134] In particular embodiments, X15 is selected from R, K, Orn and modified forms thereof; especially R, K or Orn; more especially K or Orn; most especially Orn.

[0135] In some embodiments, X16 is selected from M, I, L, V, F, Y, W, Nle and modified forms thereof; especially M, I, L, V, F, Y, W or Nle; more especially L.

[0136] In some embodiments: X10 is absent or is A, S, G or T; X11 is N or Q;X12 is D or E; X13 is K, R or hR; X14 is A, S, G or T; X15 is R, K or Orn; and X16 is M, I, L, V, F, Y, W or Nle.

[0137] In exemplary embodiments: X10 is G; X11 is N; X12 is D; X13 is K, R or hR; X14 is A or G; X15 is K or Orn; and / or X16 is L.

[0138] In exemplary embodiments: X1 is G or E; X2 is F, Bip or Bpa; X3 is W; X4 is S or hS; X5 is K or R; X6 is K or S; X7 is K or R; X8is K, R, Dab or hR; X9 is W, Bpa or Bip; X10 is G; X11 is N; X12 is D; X13is K, R or hR; X14 is A or G; X15 is K or Orn; and / orX16 is L.

[0139] The molecule of the present disclosure may, in some embodiments, comprise, consist or consist essentially of an amino acid sequence represented by Formula III: GNDCLGX2WX4ACNPX5NDKCCANX29VCSSKHX8X9CKAX15L (III) wherein: X2, X4, X5, X8, X9 and X29 are as defined for Formula I supra; and X15 is Orn; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1.

[0140] In some embodiments, the molecule of the present disclosure comprises, consists or consists essentially of an amino acid sequence represented by Formula VI: GNDCLGX2WX4ACNPX5NDKCCANLVCSSKHX8X9CKAX15L (VI) wherein: X2, X4, X5, X8 and X9 are as defined for Formula IV supra; and X15 is Orn; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1.

[0141] Suitable embodiments of each of X2, X4, X5, X8, X9 and X29 are as described supra.

[0142] In some embodiments, X2 is F or Bip; X4 is S or hS; X5 is K or R; X8 is K or Dab; and / or X9 is W or Bpa. In some embodiments, X2 is F, A or Bip; X4 is S or hS; X5 is K or R; X8 is K or Dab; X9 is W, A or Bpa; and / or X29 is L or A.

[0143] The molecule of the present disclosure, in some embodiments, comprises, consists or consists essentially of an amino acid sequence represented by Formula (VIII): Z1CLX1X2X3X4ACNPX5NDKCCANX29VCSX6X7HX8X9CZ2 (VIII) wherein: X1 to X9 and X29 are as defined for Formula I supra; and Z1 and Z2 are independently absent or are independently selected from at least one of a proteinaceous component consisting of from about 1 to about 50 amino acid residues (and all integer residues in between), and a protecting component;wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1.

[0144] In some embodiments, comprises, consists or consists essentially of an amino acid sequence represented by Formula (IX): Z1CLX1X2X3X4ACNPX5NDKCCANLVCSX6X7HX8X9CZ2 (IX) wherein: X1 to X9 are as defined for Formula IV supra; and Z1 and Z2 are independently absent or are independently selected from at least one of a proteinaceous component consisting of from about 1 to about 50 amino acid residues (and all integer residues in between), and a protecting component; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1.

[0145] In some embodiments, Z1 is absent or is a proteinaceous component consisting of from about 1 to about 10 amino acid residues (and all integer residues in between); especially about 2 to about 4 amino acid residues (and all integer residues in between). The amino acid residues are selected from any amino acid residues.

[0146] In some embodiments, Z2 is absent or is a proteinaceous component consisting of from about 1 to about 10 amino acid residues (and all integer residues in between); especially about 3 to about 5 amino acid residues (and all integer residues in between). The amino acid residues are selected from any amino acid residues.

[0147] Suitable embodiments of X1 to X9 and X29 are as discussed supra for Formulae I and IV.

[0148] In some embodiments, the molecule of the present disclosure comprises, consists or consists essentially of an amino acid sequence represented by Formula (X): Z1X10X11X12CLX1X2X3X4ACNPX5NDKCCANX29VCSX6X7HX8X9CX13X14X15X16Z2 (X) wherein: X1 to X16 and X29 are as defined for Formulae I and II supra; and Z1 and Z2 are independently absent or are independently selected from at least one of a proteinaceous component consisting of from about 1 to about 50 amino acid residues (and all integer residues in between), and a protecting component; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1.

[0149] In some embodiments, the molecule of the present disclosure comprises, consists or consists essentially of an amino acid sequence represented by Formula (XI): Z1X10X11X12CLX1X2X3X4ACNPX5NDKCCANLVCSX6X7HX8X9CX13X14X15X16Z2 (XI) wherein: X1 to X16 are as defined for Formulae IV and V supra; and Z1 and Z2 are independently absent or are independently selected from at least one of a proteinaceous component consisting of from about 1 to about 50 amino acid residues (and all integer residues in between), and a protecting component; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1.

[0150] Suitable embodiments of X1to X16and X29are as discussed supra for Formulae I, II, IV and V and embodiments of Z1 and Z2 are as discussed supra for Formulae VIII and IX.

[0151] In particular embodiments, Z1and Z2are absent.

[0152] In some embodiments, the molecule of the present disclosure comprises, consists or consists essentially of an amino acid sequence represented by Formula XII: Z1GNDCLGX2WX4ACNPX5NDKCCANX29VCSSKHX8X9CKAX15LZ2 (XII) wherein: X2, X4, X5, X8, X9 and X29 are as defined for Formula I supra; X15 is Orn; and Z1 and Z2 are independently absent or are independently selected from at least one of a proteinaceous component consisting of from about 1 to about 50 amino acid residues (and all integer residues in between), and a protecting component; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1.

[0153] In some embodiments, the molecule of the present disclosure comprises, consists or consists essentially of an amino acid sequence represented by Formula XIII: Z1GNDCLGX2WX4ACNPX5NDKCCANLVCSSKHX8X9CKAX15LZ2 (XIII) wherein: X2, X4, X5, X8 and X9 are as defined for Formula IV supra; X15 is Orn; andZ1 and Z2 are independently absent or are independently selected from at least one of a proteinaceous component consisting of from about 1 to about 50 amino acid residues (and all integer residues in between), and a protecting component; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1.

[0154] Suitable embodiments of X2, X4, X5, X8, X9 and X29 are as discussed supra for Formulae I and IV and embodiments of Z1 and Z2 are as discussed supra for Formulae VIII and IX.

[0155] In particular embodiments, Z1 and Z2 are absent.

[0156] In specific embodiments, the molecule of the present disclosure comprises, consists or consists essentially of an amino acid sequence represented by any one of SEQ ID NOs: 2-33 and 51-54: GNDCLGFWSACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 2]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 3]; GNDCLGX19WSACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 4]; GNDCLGFWX20ACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 5]; GNDCLGFWSACNPRNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 6]; GNDCLGFWSACNPKNDKCCANLVCSKKHKWCKAX17L [SEQ ID NO: 7]; GNDCLGFWSACNPKNDKCCANLVCSSKHX21WCKAX17L [SEQ ID NO: 8]; GNDCLGX19WSACNPKNDKCCANLVCSSKHX21WCKAX17L [SEQ ID NO: 9]; GNDCLGX19WX20ACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 10]; GNDCLGX19WSACNPRNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 11]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX18CKGX17L [SEQ ID NO: 12]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX18CKAKL [SEQ ID NO: 13]; GNDCLEFWSACNPKNDKCCANLVCSSKHKX18CX22GKL [SEQ ID NO: 14]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX18CX22GKL [SEQ ID NO: 15]; GNDCLEFWSACNPKNDKCCANLVCSSKHKWCX22GKL [SEQ ID NO: 16]; GNDCLEFWSACNPKNDKCCANLVCSSKHKX18CKGKL [SEQ ID NO: 17]; GNDCLGX18WSACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 18]; GNDCLGFWSACNPKNDKCCANLVCSSKHKWCRAX17L [SEQ ID NO: 19]; GNDCLGFWSACNPKNDKCCANLVCSSRHKWCKAX17L [SEQ ID NO: 20];GNDCLGFWSACNPKNDKCCANLVCSSKHRWCKAX17L [SEQ ID NO: 21]; GNDCLGFWSACNPKNDKCCANLVCSSKHX22WCKAX17L [SEQ ID NO: 22]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX19CKAX17L [SEQ ID NO: 23]; GNDCLGX18WSACNPKNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 24]; GNDCLGX19WSACNPKNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 25]; GNDCLGFWX20ACNPKNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 26]; GNDCLGFWSACNPRNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 27]; GNDCLGFWSACNPKNDKCCANLVCSKKHKX18CKAX17L [SEQ ID NO: 28]; GNDCLGFWSACNPKNDKCCANLVCSSRHKX18CKAX17L [SEQ ID NO: 29]; GNDCLGFWSACNPKNDKCCANLVCSSKHRX18CKAX17L [SEQ ID NO: 30]; GNDCLGFWSACNPKNDKCCANLVCSSKHX22X18CKAX17L [SEQ ID NO: 31]; GNDCLGFWSACNPKNDKCCANLVCSSKHX21X18CKAX17L [SEQ ID NO: 32]; GNDCLGX19WSACNPKNDKCCANLVCSKKHKWCKAX17L [SEQ ID NO: 33]; GNDCLGAWSACNPKNDKCCANLVCSSKHX21WCKAX17L [SEQ ID NO: 51]; GNDCLGX19WSACNPKNDKCCANAVCSSKHX21WCKAX17L [SEQ ID NO: 52]; GNDCLGX19WSACNPKNDKCCANLVCSSKHX21ACKAX17L [SEQ ID NO: 53]; and GNDCLGX19WSACNPKNDKCCANAVCSSKHX21ACKAX17L [SEQ ID NO: 54], wherein: X17 is Orn; X18 is Bpa; X19 is Bip; X20 is hS; X21 is Dab; and X22 is hR.

[0157] In some embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence represented by any one of SEQ ID NOs: 2-33. In some embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence represented by any one of SEQ ID NOs: 2-11 or 2-11, 52 or 53. In some embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence represented by SEQ ID NO: 2 or 9. In some embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence represented by SEQ ID NO: 9. In some embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence represented by SEQ ID NO: 9, 52 or 53. In some embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence represented by SEQ ID NO: 53.

[0158] In some embodiments, the molecules of the present disclosure have at least six cysteine residues. Preferably the molecules of the present disclosure have sixcysteine residues. In such embodiments, the six cysteine residues may be bonded in pairs to form three disulfide bonds.

[0159] Spider venom peptides are typically known to comprise six cysteine residues, with a disulfide bond connectivity between cysteine residues I and IV, II and V, and III and VI (numbered from the N-terminus). Preferably, this disulfide connectivity is present in the molecules of the present disclosure, especially the molecules of Formulae I- VI and VIII-XIII and any one of SEQ ID NOs: 2 to 33 and 51-54.

[0160] In particular embodiments, the six cysteine residues in the molecule are bonded in pairs to form three disulfide bonds. Suitably, the disulfide bonds may be formed between the side chains of Cys 1 and Cys 16, Cys 8 and Cys 21, and Cys 15 and Cys 28 (numbered in accordance with the amino acid sequence of Formula I starting at the N- terminal Cys residue).

[0161] Without wishing to be bound by theory, this disulfide bond connectivity forms a cystine knot motif in which a ring or 'loop' is formed by two of the disulfide bonds and their connecting backbone segments, through which the third disulfide bond is threaded. Peptides comprising a cystine knot motif have high levels of chemical and thermal stability, which may be advantageous for therapeutic use.

[0162] In some embodiments, one or more of the disulfide bonds of the molecule of the present disclosure, including the molecule of any one of Formulae I-VI and VIII-XIII, are replaced with a suitable alternative, such as a diselenide bond, a lanthionine bond, a lactam bond or a dimethylene bond. In particular embodiments, at least two cysteine residues are substituted with selenocysteine residues. The selenocysteine residues in the sequences must be positioned such that when the peptide is oxidised, a diselenide bond is produced between the side chains of two selenocysteine residues.

[0163] Accordingly, in another aspect, there is provided a molecule comprising, consisting or consisting essentially of an amino acid sequence represented by Formula XIV: X23LX1X2X3X4AX24NPX5NDKX25X26ANX29VX27SX6X7HX8X9X28 (XIV) wherein: X1 to X9 and X29 are as defined for Formula I supra; X23 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X26; X24 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X27; X25 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X28;X26 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X23; X27 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X24; X28 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X25; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1.

[0164] In another aspect, there is provided a molecule comprising, consisting or consisting essentially of an amino acid sequence represented by Formula VII: X23LX1X2X3X4AX24NPX5NDKX25X26ANLVX27SX6X7HX8X9X28 (VII) wherein: X1 to X9 are as defined for Formula IV supra; X23 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X26; X24 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X27; X25 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X28; X26 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X23; X27 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X24; X28 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X25; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1.

[0165] While any covalent cross-links, including chemical linkers, are envisaged, suitable covalent cross-links include, but are not limited to, a disulfide bond, a diselenide bond, a lanthionine bridge, an amide bond, an ester linkage, a thioester linkage, a carbamoyl linkage, an alkyl linkage, an alkenyl linkage, an ether linkage, a thioether linkage, an amine linkage or a thioamide linkage.

[0166] A skilled person will be well aware of suitable amino acids which will allow the formation of the covalent cross-links. For example, in some embodiments, X23 to X28 are independently selected from the group consisting of C, K, R, D, E, penicillamine, selenocysteine, diaminopropionic acid, mercaptoproline and modified forms thereof; especially C, K, R, D, E, penicillamine, selenocysteine, diaminopropionic acid or mercaptoproline; more especially C, K, R, D, E, penicillamine, selenocysteine or diaminopropionic acid; most especially C, K, R, D or E.

[0167] For example, cysteine residues may be included for formation of a disulfide bond, acidic (e.g. D or E) and basic residues (e.g. R or K) may be included for formation of a lanthionine bridge, selenocysteine residues may be included for formation of a diselenide bond, penicillamine residues may be included for formation of a disulfide bond or for formation of a thioether linkage with 2-methylbenzoyl, for example, and diaminopropionic acid may be included to participate in a lanthionine bridge.

[0168] In some embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence represented by Formula XV: X10X11X12X23LX1X2X3X4AX24NPX5NDKX25X26ANX29VX27SX6X7HX8X9X28X13X14X15X16 (XV) wherein: X1 to X16 and X29 are as defined for Formulae I and II; and X23 to X28 are as defined for Formula XIV; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1.

[0169] In some embodiments, the molecule comprises, consists or consists essentially of an amino acid sequence represented by Formula XVI: X10X11X12X23LX1X2X3X4AX24NPX5NDKX25X26ANLVX27SX6X7HX8X9X28X13X14X15X16 (XVI) wherein: X1 to X16 are as defined for Formulae IV and V; and X23 to X28 are as defined for Formula VII; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1.

[0170] Suitable embodiments for each of X1 to X16 and X29 are as described for Formulae I, II, IV and V, and suitable embodiments for each of X23 to X28 are as defined for Formulae XIV and VII supra.

[0171] In some embodiments, the molecule of the present disclosure comprises, consists or consists essentially of an amino acid sequence represented by Formula XVII: GNDX23LGX2WX4AX24NPX5NDKX25X26ANX29VX27SSKHX8X9X28KAX15L (XVII) wherein: X2, X4, X5, X8, X9 and X29 are as defined for Formula I supra; X15 is Orn; and X23 to X28 are as defined for Formula XIV; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1.

[0172] In some embodiments, the molecule of the present disclosure comprises, consists or consists essentially of an amino acid sequence represented by Formula XVIII: GNDX23LGX2WX4AX24NPX5NDKX25X26ANLVX27SSKHX8X9X28KAX15L (XVIII) wherein: X2, X4, X5, X8 and X9 are as defined for Formula IV supra; X15 is Orn; and X23 to X28 are as defined for Formula VII; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1.

[0173] Suitable embodiments for each of X2, X4, X5, X8, X9 and X29 are as described for Formulae I and IV, and suitable embodiments for each of X23 to X28 are as defined for Formulae XIV and VII supra.

[0174] In any one of the aspects disclosed herein, the molecule is suitably a proteinaceous molecule.

[0175] The molecule may be of any suitable length, such as up to 150, 140, 135, 130, 120, 110, 100, 90, 80, 70, 60, 50, 40 or 35 amino acid residues in length. In some embodiments, the molecule comprises, consists or consists essentially of from 28 to 150 amino acid residues (and all integer residues therebetween), including 28 to 140, 28 to 135, 28 to 130, 28 to 120, 28 to 110, 28 to 100, 28 to 90, 28 to 80, 28 to 70, 28 to 60, 28 to 50, 28 to 40 or 28 to 35, or 28, 29, 30, 31, 32, 33, 34 or 35 amino acid residues.

[0176] In some embodiments, the molecule is a selective antagonist of Nav1.1 and / or Nav1.7, over at least one other voltage-gated sodium channel subtype, such as Nav1.4, Nav1.5 and Nav1.6; especially Nav1.6. In some embodiments, the molecule of the present disclosure selectively inhibits Nav1.1 and / or Nav1.7 over the other subtypes ofvoltage-gated sodium channel (e.g. Nav1.2-Nav1.6, Nav1.8 and Nav1.9). In some embodiments, the molecule exhibits Nav1.1 and / or Nav1.7 selectivity of greater than about 2-fold, 5-fold, 10-fold, 20-fold, 50-fold or greater than about 100-fold with respect to antagonism of another voltage-gated sodium channel subtype, such as Nav1.6. In other embodiments, the molecule displays at least 50-fold greater antagonism of Nav1.1 and / or Nav1.7 than another voltage-gated sodium channel subtype. In some embodiments, the molecule exhibits Nav1.1 and / or Nav1.7 selectivity of greater than about 50-fold with respect to antagonism of Nav1.6. In further embodiments, the molecule displays at least 100-fold greater antagonism of Nav1.1 and / or Nav1.7 than another voltage-gated sodium channel subtype. In still further embodiments, the molecule displays at least 500-fold greater antagonism of Nav1.1 and / or Nav1.7 than another voltage-gated sodium channel subtype. In yet further embodiments, the molecule displays at least 1000-fold greater antagonism of Nav1.1 and / or Nav1.7 than another voltage-gated sodium channel subtype.

[0177] The molecule of the present disclosure is an antagonist of Nav1.1 and / or Nav1.7, especially Nav1.1 and Nav1.7. In some embodiments, the molecule of the invention has an IC50 for Nav1.1 and / or Nav1.7 of 400 nM or less, 300 nM or less, 200 nM or less, 150 nM or less, 140 nM or less, 130 nM or less, 120 nM or less, 110 nM or less, 100 nM or less, 90, nM or less, 80 nM or less, 70 nM or less, 60 nM or less, 50 nM or less, 40 nM or less, 30 nM or less, 20 nM or less, 10 nM or less or 1 nM or less; especially 100 nM or less. In particular embodiments, the IC50for Nav1.1 and / or Nav1.7 is at least 2-fold, 5-fold, 10- fold, 20-fold or 50-fold lower than the IC50 for Nav1.6 (i.e. the molecule is a more potent inhibitor of Nav1.1 and / or Nav1.7 compared to Nav1.6); especially at least 2-fold lower than the IC50 for Nav1.6.

[0178] In exemplary embodiments, the molecule has an IC50 of 100 nM or less for Nav1.1 and Nav1.7, and an IC50 for Nav1.1 at least two-fold lower than the IC50 for Nav1.6.

[0179] In particular embodiments, the IC50 values are determined using automated whole-cell patch-clamp electrophysiology using a Sophion QPatch 16X platform with HEK 293 cells stably co-expressing the relevant human NaV subtypes and the human β1 auxiliary subunit. Cells are maintained at a holding potential –80 mV and Na+currents are elicited by 20-ms voltage steps to 0 mV from a –120 mV conditioning pulse applied for 200 ms. To obtain the concentration–response curves and calculate the IC50, cells maintained at the holding potential are incubated at each dose of the molecule of the invention for 5 mins with increasing concentrations of the molecule. The IC50 values are then obtained by fitting a Hill equation with variable slope to concentration–response curves via linear regression, using a suitable program, such as Prism (GraphPad Software, San Diego, CA, USA). Other methods for determining IC50 values are known in the art.

[0180] In some embodiments, the molecules of the present disclosure have a primary, secondary or tertiary amide, a hydrazide, a hydroxamide or a free-carboxyl group at the C-terminus and / or a primary amine or acetamide at the N-terminus. In preferred embodiments, the molecules of the present disclosure have a primary amide (i.e. C- terminal amide) or a free carboxyl group (i.e. C-terminal acid) at the C-terminus and a primary amine at the N-terminus, especially a primary amide at the C-terminus and a primary amine at the N-terminus.

[0181] Cyclisation of the molecules of the present disclosure is also contemplated. In such embodiments, the molecules of the present disclosure are cyclic peptides and, thus, may not comprise N- and / or C-terminal amino acid residues. In particular embodiments, the molecule is cyclised through N-to-C cyclisation (head to tail cyclisation), preferably through an amide bond (i.e. an amide bond between the N- and C- termini of the linear peptide). Such peptides do not possess N- or C-terminal amino acid residues. In particular embodiments, the molecules of the present disclosure have an amide-cyclised peptide backbone. In other embodiments, the molecules of the present disclosure are cyclised using side-chain to side-chain cyclisation, such as through a disulfide bond or a lactam bridge.

[0182] A linker may be added to the amino acid sequence to facilitate cyclisation of the molecule. In some embodiments, the N- and C-termini are linked using a linking component. The linking component may be a peptide linker such that cyclisation produces an amide-cyclised peptide backbone. Variation within the peptide sequence of the linking component is possible, such that the linking component may be modified to alter the physicochemical properties of the molecules and potentially reduce side effects or otherwise improve the therapeutic use of the molecules, for example, by improving stability. The linking component will be of suitable length to span the distance between the N- and C-termini of the peptide without substantially altering the structural conformation of the molecule, for example, a peptidic linking component may be 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acid residues in length. In some embodiments, longer or shorter peptidic linking components may be required.

[0183] In some embodiments, the molecule of any one of Formulae I-XVIII as discussed supra has at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence similarity to the amino acid sequence of any one of SEQ ID NOs: 2 to 33 and 51 to 54 or any one of SEQ ID NOs: 2 to 33, especially any one of SEQ ID NOs: 2 to 11, or 51 to 53, more especially SEQ ID NO: 9 or 53. In some embodiments, the molecule of any one of Formulae I-XVIII as discussed supra has at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of any one of SEQ ID NOs: 2 to 33 and 51 to 54 or any one of SEQ ID NOs: 2 to 33, especially any one of SEQ ID NOs: 2 to 11, or 51 to 53, more especially SEQ ID NO: 9 or 53. In such molecules, the variance occurs at one or more of X1 to X29, Z1 and Z2 when present in the subject Formula.

[0184] The present disclosure also contemplates molecules that are variants of any one of SEQ ID NOs: 2 to 33 and 51 to 54 or any one of SEQ ID NOs: 2 to 33, especially any one of SEQ ID NOs: 2 to 11, or 51 to 53, more especially SEQ ID NO: 9 or 53. Such “variant” molecules include molecules derived from any one of SEQ ID NOs: 2 to 33 and 51 to 54 or any one of SEQ ID NOs: 2 to 33, especially any one of SEQ ID NOs: 2 to 11, or 51 to 53, more especially SEQ ID NO: 9 or 53, by deletion or addition of one or more amino acids (such as from 1-50 amino acid residues and all integer amino acids therebetween) to the N-terminal and / or C-terminal end of the molecule, deletion or addition of one or more amino acids (such as from 1-5 amino acid residues and all integer amino acids therebetween) at one or more sites in the molecule, or substitution of one or more amino acids at one or more sites in the molecule. For example, in some embodiments, the variant molecule comprises an addition of one amino acid residue or deletion of one amino acid residue.

[0185] Variant molecules encompassed by the present disclosure are biologically active, that is, they continue to possess the desired biological activity of the parent molecule, for example, Nav1.1 and / or Nav1.7 antagonism (especially Nav1.1 and Nav1.7 antagonism) and, in some embodiments, selectivity for Nav1.1 and / or Nav1.7 over at least one other voltage-gated sodium channel as discussed herein. Such variants may result from, for example, genetic polymorphism or from human manipulation.

[0186] The molecules of any one of SEQ ID NOs: 2 to 33 and 51 to 54 may be altered in various ways, including amino acid substitutions, deletions, truncations and additions. Methods for such manipulations are generally known in the art. For example, amino acid sequence variants of any one of SEQ ID NOs: 2 to 33 and 51 to 54 may be prepared by mutagenesis of nucleic acids encoding the amino acid sequence of any one of SEQ ID NOs: 2 to 33 and 51 to 54. Methods for mutagenesis and nucleotide sequence alterations are well known in the art. Refer to, for example, Kunkel (1985) Proc. Natl. Acad. Sci. USA. 82: 488-492; Kunkel, et al. (1987) Methods in Enzymol, 154: 367-382; and Daggett, et al. (2009) ACS Chem Biol, 4(2): 109-113. Recursive ensemble mutagenesis (REM), a technique which enhances the frequency of functional mutants in the libraries, can be used in combination with screening assays to identify active variants (Arkin and Yourvan (1992) Proc. Natl. Acad. Sci. USA 89: 7811-7815; Delgrave et al., (1993) Protein Engineering, 6: 327-331). Variant molecules may also be designed using medicinal chemistry approaches standard in the art.

[0187] Conservative substitutions, such as exchanging one amino acid with another having similar properties, may be particularly desirable. Variant molecules of the present disclosure may contain conservative amino acid substitutions (e.g. 1, 2 or 3 substitutions) at various locations along their sequence, as compared to a parent or reference amino acid sequence, such as any one of SEQ ID NOs: 2 to 33 and 51 to 54.

[0188] Variant molecules of the present disclosure may contain conservative amino acid substitutions at various locations along their sequence, as compared to a parent (e.g. naturally-occurring or reference) amino acid sequence, such as any one of SEQ ID NOs: 2 to 33 and 51 to 54 or any one of SEQ ID NOs: 2 to 33, especially any one of SEQ ID NOs: 2 to 11, or 51 to 53, more especially SEQ ID NO: 9 or 53. A “conservative amino acid substitution” is one in which the amino acid residue is replaced with an amino acid residue having a similar side chain. Families of amino acid residues having similar side chains have been defined in the art as discussed in detail below.

[0189] Acidic: The residue has a negative charge due to loss of a proton at physiological pH and the residue is attracted by aqueous solution so as to seek the surface positions in the conformation of a peptide in which it is contained when the peptide is in aqueous medium at physiological pH. Amino acids having an acidic side chain include glutamic acid and aspartic acid.

[0190] Basic: The residue has a positive charge due to association with protons at physiological pH or within one or two pH units thereof (e.g. histidine) and the residue is attracted by aqueous solution so as to seek the surface positions in the conformation of a peptide in which it is contained when the peptide is in aqueous medium at physiological pH. Amino acids having a basic side chain include arginine, lysine and histidine.

[0191] Charged: The residue is charged at physiological pH or within one or two pH units thereof (e.g. histidine) and, therefore, includes amino acids having acidic or basic side chains, such as glutamic acid, aspartic acid, arginine, lysine and histidine.

[0192] Hydrophobic: The residue is not charged at physiological pH and the residue is repelled by aqueous solution so as to seek the inner positions in the conformation of a peptide in which it is contained when the peptide is in aqueous medium at physiological pH. Amino acids having a hydrophobic side chain include tyrosine, valine, isoleucine, leucine, methionine, norleucine, phenylalanine and tryptophan.

[0193] Neutral / polar: The residues are not charged at physiological pH but the residue is not sufficiently repelled by aqueous solutions so that it would seek inner positions in the conformation of a peptide in which it is contained when the peptide is in aqueous medium at physiological pH. Amino acids having a neutral / polar side chain include asparagine, glutamine, cysteine, serine and threonine.

[0194] Amide-containing: The residues contain an amide in their side chain, such as glutamine and asparagine.

[0195] Aromatic: The residues contain an aromatic group in their side chain and include phenylalanine, tyrosine, histidine and tryptophan.

[0196] This description also characterises certain amino acids as “small” since their side chains are not sufficiently large, even if polar groups are lacking, to confer hydrophobicity. With the exception of proline, “small” amino acids are typically considered as those with four carbons or less when at least one polar group is on the side chain and three carbons or less when not. Amino acids having a small side chain include glycine, serine, alanine and threonine. The gene-encoded secondary amino acid proline is a special case due to its known effects on the secondary conformation of peptide chains. The structure of proline differs from all the other naturally-occurring amino acids in that its side chain is bonded to the nitrogen of the α-amino group, as well as the α-carbon. For the purposes of the present disclosure, proline is not classified as a “small” amino acid unless otherwise specified.

[0197] The degree of attraction or repulsion required for classification as polar or non-polar is arbitrary and, therefore, amino acids specifically contemplated by the present disclosure have been classified as one or the other. Most amino acids not specifically named can be classified on the basis of known behaviour.

[0198] Amino acid residues can be further sub-classified as cyclic or non-cyclic, and aromatic or non-aromatic, self-explanatory classifications with respect to the side- chain substituent groups of the residues, and as small or large. The residue is considered small if it contains a total of four carbon atoms or less, inclusive of the carboxyl carbon, provided an additional polar substituent is present; three or less if not. Small amino acid residues are, of course, always non-aromatic. Dependent on their structural properties, amino acid residues may fall into two or more classes. For the naturally-occurring protein amino acids, sub-classification according to this scheme is presented in Table 1 in Section 1 supra.

[0199] Conservative amino acid substitution also includes groupings based on side chains. For example, a group of amino acids having aliphatic side chains is glycine, alanine, valine, leucine and isoleucine; a group of amino acids having aliphatic-hydroxyl side chains is serine and threonine; a group of amino acids having amide-containing side chains is asparagine and glutamine; a group of amino acids having aromatic side chains is phenylalanine, tyrosine, histidine and tryptophan; a group of amino acids having basic side chains is lysine, arginine and histidine; and a group of amino acids having sulfur-containing side chains is cysteine and methionine. For example, it is reasonable to expect that replacement of an aspartic acid with a glutamic acid, a threonine with a serine, a lysinewith an arginine, a tyrosine with a phenylalanine, an asparagine with a glutamine, or a similar replacement of an amino acid with a structurally related amino acid will not have a major effect on the properties of the resulting variant molecule of the present disclosure. Whether an amino acid change results in a molecule that inhibits Nav1.1 and Nav1.7 can readily be determined by assaying its activity, examples of which are described herein. Conservative substitutions are shown in Table 2. Amino acid substitutions falling within the scope of the present disclosure, are, in general, accomplished by selecting substitutions that do not differ significantly in their effect on maintaining (a) the structure of the peptide backbone in the area of the substitution, (b) the charge or hydrophobicity of the molecule at the target site, or (c) the bulk of the side chain. After the substitutions are introduced, the variants are screened for biological activity. TABLE 2 EXEMPLARY AND PREFERRED AMINO ACID SUBSTITUTIONS Original Residue Exemplary Substitutions Preferred SubstitutionsOriginal Residue Exemplary Substitutions Preferred Substitutions Trp Tyr Phe Tyr, tions can be grouped into three categories based on the identity of the side chains. The first group includes glutamic acid, aspartic acid, arginine, lysine and histidine, which all have charged side chains; the second group includes glycine, serine, threonine, cysteine, tyrosine, glutamine and asparagine; and the third group includes leucine, isoleucine, valine, alanine, proline, phenylalanine, tryptophan, methionine and norleucine, as described in Zubay, Biochemistry, third edition, Wm.C. Brown Publishers (1993).

[0201] Thus, a predicted non-essential amino acid residue in a molecule of the present disclosure is typically replaced with another amino acid residue from the same side chain family. Alternatively, mutations can be introduced randomly along all or part of the coding sequence of a molecule of the present disclosure, such as by saturation mutagenesis, and the resultant mutants can be screened for an activity of the parent polypeptide, as described for example herein, to identify mutants which retain that activity. Following mutagenesis of the coding sequences, the encoded molecule can be expressed recombinantly and its activity determined. A “non-essential” amino acid residue is a residue that can be altered from the wild-type sequence of an embodiment molecule of the present disclosure without abolishing or substantially altering one or more of its activities. Suitably, the alteration does not substantially alter one of these activities, for example, the activity is at least 20%, 40%, 60%, 70%, 80%, 90% or 95% of that of the wild-type. By contrast, an “essential” amino acid residue is a residue that, when altered from the wild-type sequence of an embodiment molecule of the present disclosure, results in abolition of a significant level of an activity of the parent molecule, for example, less than 20% of the wild-type activity is present.

[0202] Accordingly, the present disclosure also contemplates variants of the molecules of any one of SEQ ID NOs: 2 to 33 and 51 to 54 or any one of SEQ ID NOs: 2 to 33, especially any one of SEQ ID NOs: 2 to 11, or 51 to 53, more especially SEQ ID NO: 9 or 53, wherein the variants are distinguished from the parent sequence by the addition, deletion, or substitution of one or more amino acid residues. In general, variants will display at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% sequence similarity to a parent or reference molecule sequence as, for example, set forth in any one of SEQ ID NOs: 2 to 33and 51 to 54 or any one of SEQ ID NOs: 2 to 33, especially any one of SEQ ID NOs: 2 to 11, or 51 to 53, more especially SEQ ID NO: 9 or 53, as determined by sequence alignment programs described elsewhere herein using default parameters. Desirably, variants will have at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% sequence identity to a parent or reference molecule sequence as, for example, set forth in any one of SEQ ID NOs: 2 to 33 and 51 to 54 or any one of SEQ ID NOs: 2 to 33, especially any one of SEQ ID NOs: 2 to 11, or 51 to 53, more especially SEQ ID NO: 9 or 53, as determined by sequence alignment programs described herein using default parameters. Variants of any one of SEQ ID NOs: 2 to 33 and 51 to 54 or any one of SEQ ID NOs: 2 to 33, especially any one of SEQ ID NOs: 2 to 11, or 51 to 53, more especially SEQ ID NO: 9 or 53, which fall within the scope of a variant molecule of the present disclosure, may differ from the parent molecule generally by at least 1, but by less than 5, 4, 3, 2 or 1 amino acid residue(s). In some embodiments, a variant molecule of the present disclosure differs from the corresponding sequence in any one of SEQ ID NOs: 2 to 33 and 51 to 54 or any one of SEQ ID NOs: 2 to 33, especially any one of SEQ ID NOs: 2 to 11, or 51 to 53, more especially SEQ ID NO: 9 or 53, by at least 1, but by less than 5, 4, 3, 2 or 1 amino acid residue(s). In some embodiments, the amino acid sequence of the variant molecule of the present disclosure comprises the molecule of any one of Formulae I-XVIII. In particular embodiments, the variant molecule of the present disclosure inhibits Nav1.1 and Nav1.7.

[0203] If the sequence comparison requires alignment, the sequences are typically aligned for maximum similarity or identity. “Looped” out sequences from deletions or additions, or mismatches, are generally considered differences. The differences are, suitably, differences or changes at a non-essential residue or a conservative substitution.

[0204] In some embodiments, calculations of sequence similarity or sequence identity between sequences are performed as follows: To determine the percent identity of two amino acid sequences or of two nucleic acid sequences, the sequences are aligned for optimal comparison purposes (e.g. gaps can be introduced in one or both of a first and a second amino acid or nucleic acid sequence for optimal alignment and non-homologous sequences can be disregarded for comparison purposes). In some embodiments, the length of a reference sequence aligned for comparison purposes is at least 40%, more usually at least 50% or 60%, and even more usually at least 70%, 80%, 90% or 100% of the length of the reference sequence. The amino acid residues or nucleotides at corresponding amino acid positions or nucleotide positions are then compared. When a position in the first sequence is occupied by the same amino acid residue or nucleotide at the corresponding position in the second sequence, then the molecules are identical at that position. For amino acid sequence comparison,when a position in the first sequence is occupied by the same or similar amino acid residue (i.e. conservative substitution) at the corresponding position in the second sequence, then the molecules are similar at that position.

[0205] The percent identity between the two sequences is a function of the number of identical amino acid residues shared by the sequences at individual positions, taking into account the number of gaps and the length of each gap, which need to be introduced for optimal alignment of the two sequences. By contrast, the percent similarity between the two sequences is a function of the number of identical and similar amino acid residues shared by the sequences at individual positions, taking into account the number of gaps and the length of each gap, which need to be introduced for optimal alignment of the two sequences. Similar considerations apply to comparison of polynucleotide sequences.

[0206] The comparison of sequences and determination of percent identity or percent similarity between sequences can be accomplished using a mathematical algorithm. In certain embodiments, the percent identity or similarity between amino acid sequences is determined using the Needleman and Wünsch, (1970, J. Mol. Biol., 48: 444- 453) algorithm which has been incorporated into the GAP program in the GCG software package (Devereaux, et al. (1984) Nucleic Acids Research, 12: 387-395), using either a Blosum 62 matrix or a PAM250 matrix, and a gap weight of 16, 14, 12, 10, 8, 6, or 4 and a length weight of 1, 2, 3, 4, 5, or 6. In some embodiments, the percent identity or similarity between amino acid sequences can be determined using the algorithm of Meyers and Miller (1989, Cabios, 4: 11-17) which has been incorporated into the ALIGN program (version 2.0), using a PAM120 weight residue table, a gap length penalty of 12 and a gap penalty of 4. In some embodiments, the percent identity or similarity between amino acid sequences can be determined using the CLUSTAL W program (Thompson et al. (1994) Nucleic Acids Research, 22(11): 4673-4680).

[0207] The molecules of the present disclosure may also encompass modified amino acid residues. Modified amino acid residues may include residues with modified side chains, N-methyl amino acids, α-methyl amino acids, residues with acetylated N-termini, beta amino acids, N-substituted amino acids and the like.

[0208] Examples of side chain modifications include modifications of amino groups, such as by acetylation with acetic anhydride or acetyl chloride; acylation of amino groups with succinic anhydride and tetrahydrophthalic anhydride; amidination with methylacetimidate; carbamoylation of amino groups with cyanate; pyridoxylation of lysine with pyridoxal-5-phosphate followed by reduction with sodium borohydride; reductive alkylation or reductive amination by reaction with an aldehyde or ketone followed by reduction with sodium borohydride, sodium cyanoborohydride or sodiumtriacetoxyborohydride; and trinitrobenzylation of amino groups with 2,4,6-trinitrobenzene sulfonic acid (TNBS). The carboxyl group may be modified by carbodiimide activation through O-acylisourea formation followed by subsequent derivatisation, for example, to a corresponding amide. The guanidine group of arginine residues may be modified by formation of heterocyclic condensation products with reagents such as 2,3-butanedione, phenylglyoxal and glyoxal. Tryptophan residues may be modified, for example, by alkylation of the indole ring with 2-hydroxy-5-nitrobenzyl bromide or sulfonyl halides, or by oxidation with N-bromosuccinimide. Tyrosine residues may be modified by nitration with tetranitromethane to form a 3-nitrotyrosine derivative.

[0209] Suitable modified arginine residues include, but are not limited to, Nω- carboxymethyl-L-arginine, Nω-carboxyethyl-L-arginine, Nα-acetyl-L-arginine, di(phenylglyoxal)-L-arginine, N-methylarginine, α-methylarginine, β-arginine, N’-nitro-L- arginine, N’,N’’-dimethyl-L-arginine, N’,N’’-diethyl-L-arginine and homoarginine.

[0210] Suitable modified lysine residues include, but are not limited to, Nε- carboxycarbonyl-L-lysine, Nε-succinimidyl-L-lysine, 2-amino-6-(2- hydroxyacetamido)hexanoic acid, Nε-3-hydroxypropyl-L-lysine, ornithine, Nε- allyloxycarbonyl-L-lysine, N-methyllysine, α-methyllysine, β-lysine, Nα-acetyl-L-lysine, Nε- acetyl-L-lysine, Nε-methyl-L-lysine, Nε-dimethyl-L-lysine, Nε-formyl-L-lysine, and diaminobutyric acid.

[0211] Suitable modified alanine residues include, but are not limited to, N- methylalanine, α-methylalanine, β-alanine, Nα-acetyl-L-alanine, α-aminobutyric acid, homoalanine and β-homoalanine.

[0212] Suitable modified leucine residues include, but are not limited to, α- methylleucine, N-methylleucine, β-leucine, t-butylglycine, homoleucine, Nα-acetyl-L- leucine and β-homoleucine.

[0213] Suitable modified glutamine residues include, but are not limited to, α- methylglutamine, Nα-methylglutamine, Nγ-methylglutamine, β-glutamine, homoglutamine, Nα-acetyl-L-glutamine and β-homoglutamine.

[0214] Exemplary modified asparagine residues include Nβ-methyl-Nβ-methoxy- asparagine, α-methylasparagine, Nα-methylasparagine, Nβ-methylasparagine, β- asparagine, homoasparagine, Nα-acetyl-L-asparagine and β-homoasparagine.

[0215] Modified glycine residues include, but are not limited to, N-methylglycine, β-homoglycine and Nα-acetyl-L-glycine.

[0216] Modified serine residues may include N-methylserine, α-methylserine, β- serine, Nα-acetyl-L-serine, isoserine, O-methylserine, homoserine and β-homoserine.

[0217] Exemplary modified threonine residues include N-methylthreonine, α- methylthreonine, β-threonine, Nα-acetyl-L-threonine, O-methylthreonine, homothreonine and β-homothreonine.

[0218] Suitable modified methionine residues include, but are not limited to, norleucine, N-methylmethionine, α-methylmethionine, β-methionine, Nα-acetyl-L- methionine, methionine sulfoxide, methionine sulfone, selenomethionine, homomethionine and β-homomethionine.

[0219] Exemplary modified proline residues include α-methylproline, β-proline, Nα-acetyl-L-proline, 4-phenoxy-pyrrolidine-2-carboxylic acid, 5,5-dimethylpyrrolidine-2- carboxylic acid, 5-methylpyrrolidine-2-carboxylic acid, homoproline and β-homoproline.

[0220] Suitable modified isoleucine residues include, but are not limited to, α- methylisoleucine, N-methylisoleucine, β-isoleucine, homoisoleucine, Nα-acetyl-L- isoleucine, β-methylisoleucine and β-homoisoleucine.

[0221] Modified valine residues may include, but are not limited to, norvaline, α- methylvaline, N-methylvaline, β-valine, β-homovaline and Nα-acetyl-L-valine.

[0222] Suitable modified phenylalanine residues include, but are not limited to, α-methylphenylalanine, N-methylphenylalanine, β-phenylalanine, β-methylphenylalanine, β,β-dimethylphenylalanine, β-hydroxyphenylalanine, homophenylalanine, Nα-acetyl-L- phenylalanine, β-homophenylalanine, 4-benzoyl-L-phenylalanine and 4,4’- biphenylalanine.

[0223] Exemplary modified tyrosine residues include α-methyltyrosine, N- methyltyrosine, β-tyrosine, β-methyltyrosine, β,β-dimethyltyrosine, β-hydroxytyrosine, homotyrosine, O-methylhomotyrosine, Nα-acetyl-L-tyrosine, O-methyltyrosine, O- ethyltyrosine, m-tyrosine and β-homotyrosine.

[0224] Suitable modified tryptophan residues include, but are not limited to, α- methyltryptophan, N-methyltryptophan, β-tryptophan, β-methyltryptophan, homotryptophan, N-formyl-tryptophan, 2-methyltryptophan, Nα-acetyl-L-tryptophan and β-homotryptophan.

[0225] Suitable modified glutamic acid residues include, but are not limited to, N-methylglutamic acid, α-methylglutamic acid, β-glutamic acid, Nα-acetyl-L-glutamic acid, glutamic acid γ-methyl ester, γ-carboxy glutamic acid, homoglutamic acid and β- homoglutamic acid.

[0226] Suitable modified aspartic acid residues include, but are not limited to, N- methylaspartic acid, α-methylaspartic acid, β-aspartic acid, Nα-acetyl-L-aspartic acid, aspartic acid β-methyl ester and β-homoaspartic acid.

[0227] Suitable modified cysteine residues include, but are not limited to, N- methylcysteine, α-methylcysteine, N-acetylcysteine, β-cysteine, β-methylcysteine, selenocysteine and homocysteine.

[0228] The molecules of the present disclosure also encompass a molecule comprising one or more unnatural amino acid residues and / or their derivatives during peptide synthesis and the use of cross-linkers and other methods which impose conformational constraints on the molecules.

[0229] Examples of incorporating unnatural amino acids and derivatives during peptide synthesis include, but are not limited to, use of 4-amino butyric acid, 6- aminohexanoic acid, 4-amino-3-hydroxy-5-phenylpentanoic acid, 4-amino-3-hydroxy-6- methylheptanoic acid, t-butylglycine, norleucine, norvaline, phenylglycine, 2-aminobutyric acid, ornithine, Nδ-acetyl-L-ornithine, sarcosine, homoserine, homoarginine, norleucine, diaminobutyric acid, 4-benzoyl-L-phenylalanine, 4,4’-biphenylalanine and / or D-isomers of amino acids. A list of unnatural amino acids contemplated by the present disclosure is shown in Table 3, in addition to the modified resides discussed supra. TABLE 3 EXEMPLARY UNNATURAL AMINO ACIDS NON-CONVENTIONALAMINOACIDS α-aminobutyric acid / 2-aminobutyric L-N-methylalanineNON-CONVENTIONAL AMINO ACIDS D-glutamic acid L-N-methylornithineNON-CONVENTIONAL AMINO ACIDS D-α-methylphenylalanine N-(carboxymethyl)glycine

[0230] Additional amino acids or other substituents may be added to the N- or C-termini of the molecules of the present disclosure. For example, the molecules of the present disclosure may form part of a longer sequence with additional amino acids added to either or both of the N- and C-termini.

[0231] Molecules with high levels of stability may be desired, for example, to increase the half-life of the molecule in a subject. Thus, in some embodiments, the molecules of the present disclosure comprise a stabilising or protecting component. The stabilising or protecting component may be conjugated at any point on the molecule. The stabilising or protecting component may be any component which delays or prevents substantial degradation of the molecule. A skilled person will be well aware of suitable stabilising or protecting components which may be used. Exemplary stabilising or protecting components include, but are not limited to, a peptide or protein such as an albumin including human serum albumin or a fragment or variant thereof, a glycine-rich homo-amino-acid polymer, a PAS sequence comprising a combination of alanine, serine and proline residues, the C-terminal peptide (CTP) of the β subunit of human chorionic gonadotropin or fragment or variant thereof, transferrin or a fragment or variant thereof, an albumin binding component, which comprises an albumin binding peptide, a bacterial albumin binding domain, an albumin-binding antibody fragment, or any combinations thereof, or an XTEN polypeptide (an extended length polypeptide with a non-naturally occurring, substantially non-repetitive sequence that is composed mainly of small hydrophilic amino acids, with the sequence having a low degree or no secondary or tertiary structure under physiologic conditions); an Fc region or single chain Fc region comprising a functional neonatal Fc receptor (FcRn) binding partner comprising an Fc domain, variant, or fragment thereof; a polymer such as a polyethylene glycol (PEG), a polysialic acid or a derivative thereof, hydroxyethyl starch or a derivative thereof, ethylene glycol / propylene glycol copolymers, carboxymethylcellulose, dextran or polyvinyl alcohol; a glycan or polysaccharide; a lipid component for example, a C6-C20fatty acyl group; or a capping component, including an acetyl group, pyroglutamate or an amino group.

[0232] In some embodiments, the protecting or stabilising component is a PEG. The PEG can be of any molecular weight, and can be branched or unbranched. In an exemplary embodiment, the molecular weight is between about 1 kDa and about 100 kDa for ease in handling and manufacturing. Other sizes can be used, depending on the desired profile (e.g. the duration of sustained release desired, the effects, if any on biological activity, the ease in handling and other known effects of the polyethylene glycol to a peptide or protein). For example, the polyethylene glycol can have an average molecular weight of about 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 200, 500, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500 or 5000 kDa.

[0233] In some embodiments, the polyethylene glycol can have a branched structure. Branched polyethylene glycols are described, for example, in U.S. Pat. No. 5,643,575; Morpurgo et al. (1996) Appl. Biochem. Biotechnol., 56: 59-72; Vorobjev et al. (1999) Nucleosides Nucleotides, 18: 2745-2750; and Caliceti et al. (1999) Bioconjug. Chem., 10: 638-646.

[0234] In some embodiments, the protecting or stabilising component is a lipid component. The lipid component may be a lipid component comprising 6 to 24 carbon atoms in the alkyl chain (and all integer carbon atoms therebetween); especially 8 to 22 carbon atoms; most especially 10 to 20 carbon atoms (e.g. a C10-C20 fatty acyl group). For example, the lipid component may be hexanoyl (C6), heptanoyl (C7), octanoyl (C8), nonanoyl (C9), decanoyl (C10), undecanoyl (C11), dodecanoyl (C12), tridecanoyl (C13), tetradecanoyl (C14), pentadecanoyl (C15), hexadecanoyl (C16), heptadecanoyl (C17) or octadecanoyl (C18). In particular embodiments, the lipid component is hexanoyl (C6), octanoyl (C8), decanoyl (C10), dodecanoyl (C12), tetradecanoyl (C14), hexadecanoyl (C16) or octadecanoyl (C18); especially tetradecanoyl, hexadecanoyl or octadecanoyl. While the lipid component may be directly conjugated to the molecule, in some embodiments, the lipid component is conjugated via a linker to the molecule, such as a PEG linker (e.g. a PEG containing from 4 to 12 ethylene glycol groups).

[0235] When present the PEG or lipid component may be, for example, conjugated to the N-terminal or C-terminal amino acid residue of the molecule or through a side chain of an amino acid residue, such as the amine of a lysine side-chain, especially through the N-terminal amino acid residue, such as through the α-amino group or through the amino group of a lysine side-chain (i.e. the ε-amino group).

[0236] In some embodiments, the protecting or stabilising component is an acetyl group or a pyroglutamate. The acetyl group or pyroglutamate may be, for example, conjugated to the N-terminal amino acid residue of the molecule. In particular embodiments, the N-terminus of the molecule is a pyroglutamide or acetamide. In some embodiments, the protecting or stabilising component is an amino group. In such embodiments, the amino group is preferably conjugated to the C-terminal amino acid residue of the molecule. In particular embodiments, the molecule of the present disclosure has a primary amide at the C-terminus.

[0237] In particular embodiments, the molecule of the present disclosure has a primary amide or a free carboxyl group (acid) at the C-terminus and a primary amine or acetamide at the N-terminus; especially a C-terminal amide, and an N-terminal amine.

[0238] While the protecting or stabilising component may be attached to the N- and / or C-terminus of the molecule, the component may also be attached to the molecule through a side-chain of an amino acid residue, such as through the amino group in theside chain of an amine- or amide-containing amino acid residue, such as lysine, arginine, glutamine and asparagine or other suitably modified side chain, especially through a lysine side chain.

[0239] The molecules of the present disclosure may be isolated or purified.

[0240] The molecules of the present disclosure may also be in the form of salts or prodrugs. The salts of the molecules of the present disclosure are preferably pharmaceutically acceptable, but it will be appreciated that non-pharmaceutically acceptable salts also fall within the scope of the present disclosure.

[0241] The molecules may be in crystalline form and / or in the form of solvates, for example, hydrates. Solvation may be performed using methods known in the art.

[0242] The present disclosure also contemplates nucleic acid molecules which encode a molecule of the present disclosure, where applicable. In this regard, it will be appreciated that some modified amino acids are not naturally encoded. Thus, in a further aspect of the present disclosure, there is provided an isolated nucleic acid molecule comprising a polynucleotide sequence that encodes a molecule of the present disclosure or is complementary to a polynucleotide sequence that encodes a molecule of the present disclosure, such as the molecule comprising, consisting or consisting essentially of a sequence represented by any one of Formulae I-XVIII or any one of SEQ ID NOs: 2 to 33 and 51 to 54 or any one of SEQ ID NOs: 2 to 33, especially any one of SEQ ID NOs: 2 to 11, or 51 to 53, more especially SEQ ID NO: 9 or 53, as described herein.

[0243] The isolated nucleic acid molecules of the present disclosure may be DNA or RNA. When the nucleic acid is in DNA form, it may be genomic DNA or cDNA. RNA forms of the nucleic acid molecules of the present disclosure are generally mRNA.

[0244] Although the nucleic acid molecules are typically isolated, in some embodiments the nucleic acid molecules may be integrated into, ligated to, or otherwise fused or associated with other genetic molecules, such as an expression vector. Generally an expression vector includes transcriptional and translational regulatory nucleic acid operably linked to the polynucleotide sequence. Accordingly, in another aspect of the present disclosure, there is provided an expression vector comprising a polynucleotide sequence that encodes a molecule of the present disclosure, such as a molecule comprising, consisting or consisting essentially of a sequence represented by any one of Formulae I-XVIII or any one of SEQ ID NOs: 2 to 33 and 51 to 54 or any one of SEQ ID NOs: 2 to 33, especially any one of SEQ ID NOs: 2 to 11, or 51 to 53, more especially SEQ ID NO: 9 or 53, as described herein.

[0245] In some embodiments, the molecules of the present disclosure may be produced inside a cell by introduction of one or more expression constructs, such as anexpression vector, that comprise a polynucleotide sequence that encodes a molecule of the present disclosure.

[0246] The present disclosure contemplates recombinantly producing the molecules of the present disclosure inside a host cell, such as a mammalian cell (e.g. Chinese hamster ovary (CHO) cell, mouse myeloma (NS0) cell, baby hamster kidney (BHK) cell or human embryonic kidney (HEK293) cell), yeast cell (e.g. Pichia pastoris cell, Saccharomyces cerevisiae cell, Schizosaccharomyces pombe cell, Hansenula polymorpha cell, Kluyveromyces lactis cell, Yarrowia lipolytica cell or Arxula adeninivorans cell), insect cell (e.g. Spodoptera frugiperda cell, such as an Sf9 cell) or bacterial cell (e.g. Escherichia coli cell, Corynebacterium glutamicum or Pseudomonas fluorescens cell).

[0247] The expression of natural or synthetic nucleic acids is typically achieved by operably linking a polynucleotide sequence encoding a molecule of the present disclosure to a regulatory element (e.g. a promoter, which may be either constitutive or inducible), suitably incorporating the construct into an expression vector and introducing the vector into a suitable host cell. Typical vectors contain transcription and translation terminators, transcription and translation initiation sequences and promoters useful for regulation of the expression of the nucleic acid. The vectors optionally comprise generic expression cassettes containing at least one independent terminator sequence, sequences permitting replication of the cassette in eukaryotes, prokaryotes or both, (e.g. shuttle vectors) and selection markers for both prokaryotic and eukaryotic systems. Vectors may be suitable for replication and integration in prokaryotes, eukaryotes, or both. See, Giliman and Smith (1979), Gene, 8: 81-97; Roberts et al. (1987) Nature, 328: 731-734; Berger and Kimmel, Guide to Molecular Cloning Techniques, Methods in Enzymology, volume 152, Academic Press, Inc., San Diego, Calif. (Berger); Sambrook et al. (1989), Molecular Cloning – a Laboratory Manual (2nd ed.) Vol. 1-3, Cold Spring Harbor Laboratory, Cold Spring Harbor Press, N.Y.; Ausubel et al., (1998) Current Protocols in Molecular Biology, eds., John Wiley & Sons, Inc.; Rosano and Ceccarelli (2014) Front Microbiol, 5:172; and Klint, et al. (2013) PLOS One, 8(5): e63865.

[0248] Expression vectors containing regulatory elements from eukaryotic viruses such as retroviruses are typically used for expression of nucleic acid sequences in eukaryotic cells. Exemplary vectors include SV40 vectors such as pSVT7 and pMT2, vectors derived from bovine papilloma virus such as pBV-1MTHA, and vectors derived from Epstein Bar virus such as pHEBO, and p2O5. Other exemplary vectors include pMSG, pAV009 / A+, pMTO10 / A+, pMAMneo-5, baculovirus pDSVE, and any other vector allowing expression of proteins under the direction of the SV-40 early promoter, SV-40 later promoter, metallothionein promoter, murine mammary tumour virus promoter, Rous sarcoma viruspromoter, polyhedrin promoter, or other promoters shown effective for expression in eukaryotic cells.

[0249] While a variety of vectors may be used, it should be noted that viral expression vectors are useful for modifying eukaryotic cells because of the high efficiency with which the viral vectors transfect target cells and integrate into the target cell genome. Illustrative expression vectors of this type can be derived from viral DNA sequences including, but not limited to, adenovirus, adeno-associated viruses, herpes-simplex viruses and retroviruses such as B, C, and D retroviruses as well as spumaviruses and modified lentiviruses. Suitable expression vectors for transfection of animal cells are described, for example, by Wu and Ataai (2000) Curr. Opin. Biotechnol., 11(2): 205-208; Vigna and Naldini (2000) J. Gene Med., 2(5): 308-316; Kay et al. (2001) Nat. Med., 7(1): 33-40; Athanasopoulos et al. (2000) Int. J. Mol. Med., 6(4): 363-375; Walther and Stein (2000) Drugs, 60(2): 249-271; and Makrides (2004) New Comprehensive Biochemistry, 38: 9-26.

[0250] The polypeptide or peptide-encoding portion of the expression vector may comprise a naturally-occurring sequence or a variant thereof, which has been engineered using recombinant techniques. In one example of a variant, the codon composition of a polynucleotide encoding a molecule of the present disclosure is modified to permit enhanced expression of the molecule of the present disclosure in a mammalian host using methods that take advantage of codon usage bias, or codon translational efficiency in specific mammalian cell or tissue types as set forth, for example, in International Publications WO 99 / 02694 and WO 00 / 42215. Briefly, these latter methods are based on the observation that translational efficiencies of different codons vary between different cells or tissues and that these differences can be exploited, together with codon composition of a gene, to regulate expression of a protein in a particular cell or tissue type. Thus, for the construction of codon-optimized polynucleotides, at least one existing codon of a parent polynucleotide is replaced with a synonymous codon that has a higher translational efficiency in a target cell or tissue than the existing codon it replaces. Although it is preferable to replace all the existing codons of a parent nucleic acid molecule with synonymous codons which have that higher translational efficiency, this is not necessary because increased expression can be accomplished even with partial replacement. Suitably, the replacement step affects 5%, 10%, 15%, 20%, 25%, 30%, more preferably 35%, 40%, 50%, 60%, 70% or more of the existing codons of a parent polynucleotide.

[0251] The expression vector is compatible with the cell in which it is introduced such that the molecule of the present disclosure is expressible by the cell. The expression vector is introduced into the cell by any suitable means which will be dependent on the particular choice of expression vector and cell employed. Such means of introduction are well-known to those skilled in the art. For example, introduction can be effected by use ofcontacting (e.g. in the case of viral vectors), electroporation, transformation, transduction, conjugation or triparental mating, transfection, infection membrane fusion with cationic lipids, high-velocity bombardment with DNA-coated microprojectiles, incubation with calcium phosphate-DNA precipitate, direct microinjection into single cells, and the like. Other methods also are available and are known to those skilled in the art. Alternatively, the vectors are introduced by means of cationic lipids, e.g., liposomes. Such liposomes are commercially available (e.g. Lipofectin®, Lipofectamine™, and the like, supplied by Invitrogen, Waltham MA, USA).

[0252] The molecules may be prepared using any suitable method, such as chemical synthesis or recombinant DNA techniques. In some embodiments, the molecules are prepared using standard peptide synthesis methods, such as solution synthesis or solid phase synthesis. The chemical synthesis of the molecules may be performed manually or using an automated synthesiser (e.g. a Liberty PRIME microwave synthesiser). For example, the linear peptides may be synthesised using solid phase peptide synthesis using either Boc or Fmoc chemistry, as described in Merrifield (1963) J Am Chem Soc, 85(14): 2149-2154; Schnolzer, et al. (1992) Int J Pept Protein Res, 40: 180-193; Cardoso, et al. (2015) Mol Pharmacol, 88(2): 291-303; and Kumar et al. (2020) ACS Omega, 5: 2345- 2354, the entire contents of which are incorporated by reference. Following deprotection and cleavage from the solid support, the linear peptides are purified using suitable methods, such as preparative chromatography, and disulfide bonds are formed using oxidation where appropriate. Suitable conditions for oxidation of the peptide will be readily determined by a person skilled in the art.

[0253] In some embodiments, the molecules of the present disclosure may be cyclised. Methods for cyclisation are known in the art. Cyclisation may be performed using several techniques, for example, as described in Davies (2003) J Pept Sci, 9: 471-501; or Thongyoo et al. (2006) Chem Commun (Camb), 27: 2848-2850. For example, N-to-C cyclisation may be conducted in the solution phase, using a dilute solution of the linear peptide in the presence of a coupling agent such as BOP (1-benzotriazole-tris-dimethyl aminophosphonium hexafluorophosphate), PyBOP (1-benzotriazolyloxy-tris-pyrrolidino phosphonium hexafluorophosphate), PyAOP (7-azabenzotriazol-1-yloxy tris pyrrolidino phosphonium hexafluorophosphate), AOP (7-azabenzotriazol-1-yloxy-tris-dimethyl aminophosphonium hexafluorophosphate), HBTU (O-(benzotriazol-1-yl)-1,1,3,3- tetramethyl uronium hexafluorophosphate), TBTU (O-(benzotriazol-1-yl)-1,1,3,3- tetramethyl uronium tetrafluoroborate), HATU (O-(7-azabenzotriazol-1-yl)-1,1,3,3- tetramethyl uronium hexafluorophosphate), HAPyU (O-(7-azabenzotriazol-1-yl)-1,1,3,3- tetramethylene uronium hexafluorophosphate), HAPipU (O-(7-azabenzotriazol-1-yl)- 1,1,3,3-pentamethylene uranium hexafluorophosphate), DCC (N,N'- dicyclohexylcarbodiimide), DIC (N,N'-diisopropylcarbodiimide), and / or EDC [1-ethyl-3-(3'-dimethylaminopropyl)carbodiimide hydrochloride]. The cyclized peptide may then be deprotected (i.e. the side chain protecting groups may then be removed) using standard techniques, followed by purification using suitable methods, such as preparative chromatography. Alternatively, N-to-C cyclization may be achieved on resin using a suitable coupling agent, such as those described above, and a suitable resin or via native chemical ligation as described in Thongyoo et al. (2006) Chem Commun (Camb), 27: 2848- 2850.

[0254] In alternative embodiments, the molecules of the present disclosure are prepared using recombinant DNA techniques, where applicable. For example, the molecules of the present disclosure may be prepared by a procedure including the steps of: (a) preparing a construct comprising a polynucleotide sequence that encodes the molecule of the present disclosure and that is operably linked to a regulatory element; (b) introducing the construct into a host cell; (c) culturing the host cell to express the polynucleotide sequence to thereby produce the encoded molecule of the present disclosure; and (d) isolating the molecule of the present disclosure from the host cell. The molecule of the present disclosure may be prepared recombinantly using standard protocols, for example, as described in Klint, et al. (2013) PLOS One, 8(5): e63865; Sambrook, et al. (1989) Molecular Cloning: A Laboratory Manual (Cold Spring Harbour Press), in particular Sections 16 and 17; Ausubel, et al. (1998) Current Protocols in Molecular Biology (John Wiley and Sons, Inc.), in particular Chapters 10 and 16; and Coligan, et al. (1997) Current Protocols in Protein Science (John Wiley and Sons, Inc.), in particular Chapters 1, 5 and 6. Under some circumstances it may be desirable to undertake oxidative disulfide bond formation of the expressed peptide after peptide expression. This may be preceded by a reductive step to provide the linear peptide. Suitable conditions for reduction and oxidation of the peptide will be readily determined by a person skilled in the art. 4. Compositions

[0255] In accordance with the present disclosure, the molecules are useful in compositions and methods for treating or at least partially inhibiting the development of a condition in which inhibiting Nav1.1 and / or Nav1.7 activity is associated with effective treatment or inhibition of such condition, such as pain, e.g. inflammatory pain, visceral pain, abdominal pain and nociceptive pain. Thus, in some embodiments, the molecules may be in the form of a pharmaceutical composition, wherein the pharmaceutical composition comprises, consists or consists essentially of a molecule of the present disclosure and a pharmaceutically acceptable excipient.

[0256] The molecule may be formulated into the pharmaceutical composition as a neutral or salt form.

[0257] As will be appreciated by those skilled in the art, the choice of pharmaceutically acceptable excipient, including a carrier or diluent, will be dependent on the route of administration and on the nature of the condition and subject to be treated. The particular carrier or delivery system and route of administration may be readily determined by a person skilled in the art. The carrier or delivery system and route of administration should be carefully selected to ensure that the activity of the molecule is not depleted during preparation of the formulation and the molecule is able to reach the site of action intact. The pharmaceutical compositions of the present disclosure may be administered through a variety of routes including, but not limited to, oral, rectal, topical, intranasal, intraocular, transmucosal, intestinal, enteral, intramuscular, subcutaneous, intramedullary, intrathecal, intraventricular, intracerebral, intravaginal, intravesical, intravenous or intraperitoneal administration; especially oral, intravenous, intramuscular, subcutaneous, intrathecal or intraperitoneal administration; more especially oral administration.

[0258] The pharmaceutical forms suitable for injectable use include sterile injectable solutions or dispersions and sterile powders for the preparation of sterile injectable solutions. Such forms should be stable under the conditions of manufacture and storage and may be preserved against reduction, oxidation and microbial contamination.

[0259] A person skilled in the art will readily be able to determine appropriate formulations for the molecules using conventional approaches. Techniques for formulation and administration may be found in, for example, Remington: The Science and Practice of Pharmacy, Adeboye Adejare and Joseph Remington (Ed), Academic Press, London, 23rdEdition, 2021.

[0260] Identification of preferred pH ranges and suitable excipients, such as antioxidants, is routine in the art, for example, as described in Katdare and Chaubel (2006) Excipient Development for Pharmaceutical, Biotechnology and Drug Delivery Systems (CRC Press). Buffer systems are routinely used to provide pH values of a desired range and may include, but are not limited to, carboxylic acid buffers, such as acetate, citrate, lactate, tartrate and succinate; glycine; histidine; phosphate; tris(hydroxymethyl)aminomethane (Tris); arginine; sodium hydroxide; glutamate; and carbonate buffers. Suitable antioxidants may include, but are not limited to, phenolic compounds such as butylated hydroxytoluene (BHT) and butylated hydroxyanisole; vitamin E; ascorbic acid; reducing agents such as methionine or sulfite; metal chelators such as ethylene diamine tetraacetic acid (EDTA); cysteine hydrochloride; sodium bisulfite; sodium metabisulfite; sodium sulfite; ascorbyl palmitate; lecithin; propyl gallate; and alpha-tocopherol.

[0261] For injection, the molecule may be formulated in an aqueous solution, suitably in physiologically compatible buffers such as Hanks’ solution, Ringer’s solution,dextrose solution or physiological saline buffer, such as phosphate buffered saline (PBS). For transmucosal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art.

[0262] The compositions of the present disclosure may be formulated for administration in the form of liquids, containing acceptable diluents (such as saline and / or sterile water), or may be in the form of lotions, creams or gels containing acceptable diluents or carriers to impart the desired texture, consistency, viscosity and appearance. Acceptable diluents and carriers are familiar to those skilled in the art and include, but are not restricted to, ethoxylated and nonethoxylated surfactants, fatty alcohols, fatty acids, hydrocarbon oils (such as palm oil, coconut oil, and mineral oil), cocoa butter waxes, silicon oils, pH balancers, cellulose derivatives, emulsifying agents such as non-ionic organic and inorganic bases, preserving agents, wax esters, steroid alcohols, triglyceride esters, phospholipids such as lecithin and cephalin, polyhydric alcohol esters, fatty alcohol esters, hydrophilic lanolin derivatives and hydrophilic beeswax derivatives.

[0263] Alternatively, the molecule can be formulated readily using pharmaceutically acceptable excipients, including carriers, well known in the art into dosages suitable for oral administration. Such excipients enable the molecules of the present disclosure to be formulated in dosage forms such as tablets, pills, capsules, liquids, gels, syrups, slurries, suspensions and the like, for oral ingestion by a patient to be treated. Suitable carriers include, but are not limited to, sugars, chitosan, starches, cellulose and its derivatives, malt, gelatin, talc, calcium sulfate, vegetable oils, synthetic oils, polyols, alginic acid, phosphate buffered solutions, emulsifiers, isotonic saline and pyrogen-free water.

[0264] Pharmaceutical formulations for parenteral administration include aqueous solutions of the composition in water-soluble form. Additionally, suspensions of the molecule of the present disclosure may be prepared as appropriate oily injection suspensions. Suitable lipophilic solvents or vehicles include fatty oils such as sesame oil, or synthetic fatty acid esters, such as ethyl oleate or triglycerides. Aqueous injection suspensions may contain substances that increase the viscosity of the suspension, such as sodium carboxymethyl cellulose, sorbitol or dextran. Optionally, the suspension may also contain suitable stabilisers or agents that increase the solubility of the molecules to allow for the preparation of highly concentrated solutions.

[0265] Sterile solutions may be prepared by combining the molecule in the required amount in the appropriate solvent with other excipients as described above as required, followed by sterilisation, such as filtration. Generally, dispersions are prepared by incorporating the various sterilised active agents into a sterile vehicle which contains the basic dispersion medium and the required excipients as described above. Sterile drypowders may be prepared by vacuum- or freeze-drying a sterile solution comprising the active agents and other required excipients as described above.

[0266] Pharmaceutical preparations for oral use can be obtained by combining the molecules with solid excipients and processing the mixture of granules, after adding suitable auxiliaries, if desired, to obtain tablets or dragee cores. Suitable excipients are, in particular, fillers such as sugars, including lactose, sucrose, mannitol or sorbitol; cellulose preparations such as, for example, maize starch, wheat starch, rice starch, potato starch, gelatin, gum tragacanth, methyl cellulose, hydroxypropylmethyl-cellulose, sodium carboxymethylcellulose and / or polyvinylpyrrolidone. If desired, disintegrating agents may be added, such as the cross-linked polyvinyl pyrrolidone, agar or alginic acid or a salt thereof, such as sodium alginate. Such compositions may be prepared by any of the methods of pharmacy but all methods include the step of bringing into association one or more therapeutic agents as described above with at least one excipient or carrier which constitutes one or more necessary ingredients. In general, the pharmaceutical compositions of the present disclosure may be manufactured in a manner that is itself known, e.g. by means of conventional mixing, dissolving, granulating, dragee-making, levigating, emulsifying, encapsulating, entrapping or lyophilising processes.

[0267] Dragee cores are provided with suitable coatings. For this purpose, concentrated sugar solutions may be used, which may optionally contain gum arabic, talc, polyvinyl pyrrolidone, carbopol gel, polyethylene glycol, and / or titanium dioxide, lacquer solutions, and suitable organic solvents or solvent mixtures. Dyestuffs or pigments may be added to the tablets or dragee coatings for identification or to characterise different combinations of particle doses.

[0268] Pharmaceuticals which can be used orally include push-fit capsules made of gelatin, as well as soft, sealed capsules made of gelatin and a plasticiser, such as glycerol or sorbitol. The push-fit capsules can contain the active agents in admixture with fillers such as lactose, binders such as starches, and / or lubricants such as talc or magnesium stearate and, optionally, stabilisers. In soft capsules, the active agents may be dissolved or suspended in suitable liquids, such as fatty oils, liquid paraffin or liquid polyethylene glycols. In addition, stabilisers may be added.

[0269] The molecules may be incorporated into modified-release preparations and formulations, for example, polymeric microsphere formulations, and oil- or gel-based formulations.

[0270] The molecules may, in some embodiments, be administered in a local rather than systemic manner, such as by injection directly into a tissue, which is preferably subcutaneous or omental tissue, often in a depot or sustained release formulation. In other embodiments, the molecule is systemically administered.

[0271] Furthermore, the molecule may be administered in a targeted drug delivery system, such as in a particle which is suitable targeted to and taken up selectively by a cell or tissue. In some embodiments, the molecule is contained or otherwise associated with a vehicle selected from liposomes, micelles, dendrimers, biodegradable particles, artificial DNA nanostructure, lipid-based nanoparticles and carbon or old nanoparticles. In illustrative examples of this type, the vehicle is selected from poly(lactic acid) (PLA), poly(glycolic acid), poly(lactic-co-glycolic acid), poly(ethylene glycol) (PEG), PLA-PEG copolymers and combinations thereof.

[0272] It is advantageous to formulate the compositions in dosage unit form for ease of administration and uniformity of dosage. The determination of the novel dosage unit forms of the present disclosure is dictated by and directly dependent on the unique characteristics of the active material, the particular therapeutic effect to be achieved and the limitations inherent in the art of compounding active materials for the treatment of disease in living subjects having a diseased condition in which bodily health is impaired as herein disclosed in detail.

[0273] While the molecule of the present disclosure may be the sole active ingredient administered to the subject, the administration of other active ingredients concurrently with said molecule is within the scope of the present disclosure. For example, in some embodiments, the molecule may be administered concurrently with one or more anti-inflammatory agents, analgesics or anaesthetics and / or an inflammatory bowel disease, irritable bowel syndrome or gastric motility disorder treatment. The molecule may be therapeutically used after the other active ingredient or may be therapeutically used together with the other active ingredient. The molecule may be administered separately, simultaneously or sequentially with the other active ingredient.

[0274] Accordingly, in another aspect of the present disclosure, there is provided a composition comprising a molecule of the present disclosure and an anti-inflammatory agent, analgesic, anaesthetic and / or an inflammatory bowel disease, irritable bowel syndrome or gastric motility disorder treatment.

[0275] Exemplary anti-inflammatory agents include non-steroidal anti- inflammatory drugs (NSAIDs) (e.g. acetylsalicylic acid (aspirin), diclofenac, diflusinal, etodolac, fenbufen, fenoprofen, flufenisal, flurbiprofen, ibuprofen, indomethacin, ketoprofen, ketorolac, meclofenamic acid, mefenamic acid, meloxicam, nabumetone, naproxen, nimesulide, nitroflurbiprofen, olsalazine, oxaprozin, phenylbutazone, piroxicam, sulfasalazine, sulindac, tolmetin, zomepirac, celecoxib, deracoxib, etoricoxib, mavacoxib or parecoxib), disease-modifying antirheumatic drugs (DMARDs) (e.g. methotrexate, leflunomide, sulfasalazine, hydroxychloroquinone, penicillamine, anatacept, baricitinib, cetolizumab, sarilumab, tocilizumab or tofacitinib), prednisone, methylprednisolone,dexamethasone, hydrocortisone, budesonide, prednisolone, etanercept, golimumab, infliximab, adalimumab, anakinra, rituximab, natalizumab, abatacept, and salts and combinations thereof.

[0276] Suitable analgesics include, but are not limited to, an opioid analgesic such as oxycodone, morphine, pethidine, codeine, hydrocodone, dihydrocodeine, dihydromorphine, fentanyl, buprenorphine, butorphanol, hydromorphone, levallorphan, levorphanol, meperidine, methadone, nalmefene, nalorphine, naloxone, naltrexone, nalbuphine, oxymorphone, tapentadol, tramadol, propoxyphene, ketobemidone or pentazocine; an NSAID as discussed supra; paracetamol; flupirtine; nefopam; retigabine; duloxetine; promethazine; carisoprodol; an anticonvulsant-type analgesic including pregabalin, gabapentin, gabapentin enacarbil, carbamazepine, topiramate or lamotrigine; a tricyclic antidepressant such as clomipramine, amitriptyline, desipramine, imipramine, doxepin or nortriptyline; an antidepressant such as trazodone, duloxetine or milnacipran; an enkephalinase inhibitor such as phosphoramidon, racecadotril, bestatin, N-([(R,S)-2- benzyl-3[(S)(2-amino-4-methylthio)butyldithio]-1-oxopropyl)-L-phenylalanine benzyl ester (RB101), RB3007, N-((S)-2-benzyl-3[(S)-2-amino-4-methylthio)butyldithio-]-1- oxopropyl)-L-alanine benzyl ester (RB120), opiorphin, thiorphin, kelatorphan, D- phenylalanine, tynorphin or spinorphin; opioid peptides such as an endorphin, an enkephalin, a dynorphin, adrenorphin, amidorphin, an endomorphin, a hemorphin, a rubiscolin, a casomorphin, a deltorphin or a dermorphin; a barbiturate such as amobarbital, aprobarbital, butabital, mephobarbital, methohexital, pentobarbital, phenobarbital, secobarbital or thiopental; an NMDA receptor antagonist such as dextromethorphan, ketamine, neramexane or memantine; an alpha-adrenergic such as clonidine, guanfacine or dexmedetomidine; a tachykinin antagonist such as aprepitant or maropitant; a muscarinic acetylcholine receptor antagonist such as oxybutynin, propiverine, trospium, flavoxate, darifenacin, solifenacin, temaverine or ipratropium; a nicotinic acetylcholine receptor agonist such as varenicline, tebanicline or nicotine; a transient receptor potential vanilloid type 1 (TRPV1) receptor agonist such as resiniferatoxin or capsaicin; a TRPV1 receptor antagonist such as capsazepine or mavatrep; a transient receptor potential ankyrin 1 (TRPA1) receptor agonist such as cinnemaldehyde; a TRPA1 receptor antagonist such as GRC 17536, CB-625, mecamylamine, 4-nitro-N-(2,2,2-trichloro-1-((4- chlorophenyl)sulfanyl)ethyl)benzamide (AMG2504), 4-methoxy-N-(2,2,2-trichloro-1-((4- chlorophenyl)sulfanyl)ethyl)benzamide (AMG5445), 4-bromo-N-(2,2,2-trichloro-1-((4- chlorophenyl)sulfanyl)ethyl)benzamide (AMG7160), N-(2,2,2-trichloro-1-((4- chlorophenyl)sulfanyl)ethyl)benzamide (AMG9090), 4-methyl-N-[2,2,2-trichloro-1-(4- nitro-phenylsulfanyl)-ethyl]-benzamide (CMP1), 4-methyl-N-[2,2,2-trichloro-1-(4- chlorophenylsulfanyl)ethyl]benzamide (CMP2), N-[2,2,2-trichloro-1-(4- chlorophenylsulfanyl)ethyl]acetamide (CMP3), 1,2,3,6-tetrahydro-1,3-dimethyl-N-[4-(1-methylethyl)phenyl]-2,6-dioxo-7H-purine-7-acetamide (HC-030031), 2-(1,3-dimethyl- 2,6-dioxo-1,2,3,6-tetrahydro-7H-purin-7-yl)-N-[4-(1-methylpropyl)phenyl]acetamide (Chembridge-5861528), 4-(4-chlorophenyl)-3-methylbut-3-en-2-oxime (AP-18), or (1E,3E)-1-(4-fluorophenyl)-2-methyl-1-penten-3-one oxime (A-967079); a transient receptor potential vanilloid subtype 3 (TRPV3) receptor antagonist such as GRC 15300 (SAR292833); a corticosteroid such as dexamethasone; a serotonin receptor agonist such as eletriptan, sumatriptan, naratriptan, solmitriptan or rizatriptan; a phosphodiesterase type 5 (PDE5) inhibitor such as sildenafil, tadalafil or vardenafil; a muscle relaxant such as diazepam, lorazepam, methocarbamol, cyclobenzaprine, metaxalone, tizanidine or baclofen; a serotonin reuptake inhibitor such as sertraline, desmethylsertraline, fluoxetine, norfluoxetine, fluvoxamine, paroxetine, citalopram, desmethylcitalopram, escitalopram, fenfluoramine, femoxetine, ifoxetine, cyanodothiepin, litoxetine, dapoxetine, nefazodone, cericlamine or trazodone; a noradrenaline reuptake inhibitor such as maprotiline, reboxetine, lofepramine, mirtazapine, oxaprotiline, fezolamine, tomoxetine, mianserin, buproprion, hydroxybuproprion, nomifensine or viloxazine; a serotonin and noradrenaline reuptake inhibitor such as venlafaxine, desvenlafaxine, clomipramine, desmethylclomipramine, duloxetine, milnacipran or imipramine; a 5-lipoxygenase inhibitor such as esculetin or zileuton; a calcium channel blocker such as ziconotide or ethosuximide; a sodium channel modulator such as bupivacaine, lidocaine, mexiletine or phenytoin; and salts and combinations thereof.

[0277] Suitable anaesthetic agents may include, but are not limited to, procaine, amethocaine, lidocaine, prilocaine, bupivacaine, levobupivacaine, ropivacaine, mepivacaine, dibucaine, benzocaine, tetracaine, etidocaine, desflurane, enflurane, halothane, isoflurane, methoxyflurane, nitrous oxide, sevoflurane, barbiturates, benzodiazepines, etomidate, ketamine, propofol, and salts and combinations thereof.

[0278] Suitable inflammatory bowel disease or irritable bowel syndrome treatments include, but are not limited to, an anti-chloinergic (e.g. dicycloverine), laxative (e.g. magnesium hydroxide, polyethylene glycol), anti-diarrhoeal (e.g. loperamide, cholestyramine, colestipol, colesevelam), a 5-HT3 antagonist such as alosetron, eluxadoline, lubiprostone, linaclotide and salts and combinations thereof.

[0279] Suitable gastric motility disorder treatments include, but are not limited to, an anti-emetic (e.g. metoclopramide, domperidone, ondansetron, promethazine, prochlorperazine, meclizine and mirtazapine), a prokinetic (e.g. erythromycin, metoclopramide, domperidone, otreotide, tegaserod and lubiprostone) diphenhydramine, sildenafil citrate, camicinal, simethicone, a H2 receptor blocker (e.g. cimetidine, famotidine and nizatidine), a proton pump inhibitor (e.g. lansoprazole, omeprazole and esomeprazole) and salts and combinations thereof.

[0280] As previously described, the molecule may be compounded for convenient and effective administration in effective amounts with a suitable pharmaceutically acceptable excipient in dosage unit form. In some embodiments, a unit dosage form may comprise the molecule in an amount in the range of from about 0.25 μg to about 2000 mg. The molecule may be present in an amount of from about 0.25 μg to about 2000 mg / mL of carrier. In embodiments where the pharmaceutical composition comprises one or more additional active ingredients, the dosages are determined by reference to the usual dose and manner of administration of the said ingredients. 5. Methods of Use

[0281] The molecules of the present disclosure have been found to inhibit Nav1.1 and Nav1.7, and in some embodiments, to have selectivity for inhibition of these voltage- gated sodium channels over one or more other voltage-gated sodium channel subtypes, such as Nav1.6. As such, the molecules of the present disclosure are considered to be useful for treating or at least partially inhibiting the development of a condition associated with Nav1.1 and / or Nav1.7 activity, such as pain or anxiety. Accordingly, a molecule of the present disclosure for use in therapy is contemplated.

[0282] In one aspect, there is provided a method of treating or at least partially inhibiting the development of a condition in which inhibiting Nav1.1 and / or Nav1.7 activity is associated with effective treatment or inhibition of the condition, comprising administering an effective amount of the molecule of the present disclosure. Further provided is a use of a molecule of the present disclosure for treating or at least partially inhibiting the development of a condition in which inhibiting Nav1.1 and / or Nav1.7 activity is associated with effective treatment or inhibition of the condition; a molecule of the present disclosure for use in treating or at least partially inhibiting the development of a condition in which inhibiting Nav1.1 and / or Nav1.7 activity is associated with effective treatment or inhibition of the condition; and a use of a molecule of the present disclosure in the manufacture of a medicament for treating or at least partially inhibiting the development of a condition in which inhibiting Nav1.1 and / or Nav1.7 activity is associated with effective treatment or inhibition of the condition.

[0283] Suitable conditions include, but are not limited to, pain, such as inflammatory pain, visceral pain, abdominal pain or nociceptive pain, and anxiety.

[0284] In some embodiments, the pain is visceral pain. This pain type is commonly the result of inflammation, swelling or stretching of the organs, blockage, decreased blood flow and / or tumours, all of which can be the result of an underlying condition.

[0285] In some embodiments, the pain is abdominal pain. In some embodiments, the pain is lower abdominal or pelvic pain.

[0286] In particular embodiments, the pain is associated with the gastrointestinal tract, including the esophagus, stomach, small intestine or large intestine. In such embodiments, the pain may be associated with condition including, but not limited to, irritable bowel syndrome, inflammatory bowel disease (e.g. ulcerative colitis or Crohn's disease), gastrointestinal inflammation, a gastric motility disorder, functional bowel disorder, gastroesophageal reflux, functional abdominal pain syndrome, ileitis or cancer of the gastrointestinal tract; especially irritable bowel syndrome, inflammatory bowel disease, gastrointestinal inflammation or a gastric motility disorder; most especially irritable bowel syndrome. Suitably, the molecule of the present disclosure substantially does not have an effect on gastric motility. In this regard, in some embodiments, the molecule of the present disclosure does not substantially modulate (e.g. slow down) the rate of gastric motility or gastric emptying, especially colonic motility.

[0287] Suitable gastric motility disorders include, but are not limited to, gastroparesis, functional dyspepsia, cannabis hyperemesis syndrome, chronic intestinal pseudo-obstruction or colonic inertia.

[0288] In some embodiments, the pain is associated with irritable bowel syndrome. In certain embodiments, the irritable bowel syndrome is diarrhoea-predominant irritable bowel syndrome (IBS-D), constipation-predominant irritable bowel syndrome (IBS-C), mixed-motility irritable bowel syndrome (IBS-M) or post-infectious irritable bowel syndrome (PI-IBS).

[0289] In some embodiments, the pain is associated with pancreatitis or kidney stones.

[0290] In some embodiments, the pain is endometrial pain or bladder pain. In some embodiments, the pain is associated with endometriosis, interstitial cystitis or a urinary tract infection. In particular embodiments, the pain is associated with endometriosis.

[0291] In some embodiments, the pain is inflammatory pain, representative examples of which include arthritic pain, including pain associated with rheumatoid arthritis, osteoarthritis, rheumatoid disease, degenerative joint disease, gout or ankylosing spondylitis. Some visceral pain types may also be classified as inflammatory pain.

[0292] Types of nociceptive pain which are contemplated by the invention include, but are not limited to, pain associated with central nervous system trauma, strains, sprains, burns, myocardial infarction or acute pancreatitis; post-operative pain; posttraumatic pain; renal colic; cancer pain including tumour related pain or pain associated with cancer therapy; or back pain, including pain associated with herniated orruptured intervertebral discs, or pain associated with abnormalities of the lumber facet joints, sacroiliac joints, paraspinal muscles or the posterior longitudinal ligament.

[0293] Other types of pain in which administration of the molecules of the invention may be useful include, but are not limited to, pain resulting from musculoskeletal disorders, including myalgia, fibromyalgia, spondylitis, sero-negative arthropathies, non- articular rheumatism, dystrophinopathy, glycogenolysis, polymyositis or pyomyositis; heart or vascular pain, including pain resulting from angina, myocardial infarction, mitral stenosis, pericarditis, Raynaud's phenomenon, scleroderma or skeletal muscle ischemia; head pain including migraine, cluster headache, tension-type headache, mixed headache or headache associated with vascular disorders; breakthrough pain; or orofacial pain, including dental pain, otic pain, burning mouth syndrome or temporomandibular myofascial pain. In some embodiments, the pain is migraine pain.

[0294] While the use of the molecule of the present disclosure for both acute pain (e.g. pain lasting for less than six months) and chronic pain (e.g. pain lasting for at least six months) is contemplated, in some embodiments, the pain is chronic pain. In particular embodiments, the subject has chronic pain, which has lasted for at least six months.

[0295] In some embodiments, the condition is anxiety. In particular embodiments, the anxiety is associated with a disorder of the gastrointestinal tract, such as irritable bowel syndrome or inflammatory bowel disease. For example, in some embodiments, the subject to be treated by the methods and uses of the disclosure may have anxiety and irritable bowel syndrome or inflammatory bowel disease.

[0296] Also provided are methods for treating or at least partially inhibiting the development of a condition associated with Nav1.1 and / or Nav1.7 activity (e.g. aberrant activity or hyperactivity) in a subject, comprising administering a molecule of the present disclosure. Suitable conditions are as discussed supra.

[0297] Also provided, in another aspect of the present disclosure is a method of treating or at least partially inhibiting the development of pain in a subject, comprising administering an effective amount of the molecule of the present disclosure to the subject. In a further aspect, there is provided a use of a molecule of the present disclosure for treating or at least partially inhibiting the development of pain in a subject; a molecule of the present disclosure for use in treating or at least partially inhibiting the development of pain in a subject; or a use of a molecule of the present disclosure in the manufacture of a medicament for treating or at least partially inhibiting the development of pain in a subject.

[0298] Suitable pain types are as discussed supra.

[0299] In particular embodiments, the pain is chronic pain.

[0300] In preferred embodiments, the pain is visceral pain or abdominal pain, especially abdominal pain. In some embodiments, the pain is lower abdominal or pelvic pain. In some embodiments, the pain is associated with irritable bowel syndrome, inflammatory bowel disease, gastrointestinal inflammation or a gastric motility disorder, such as gastroparesis, functional dyspepsia, cannabis hyperemesis syndrome, chronic intestinal pseudo-obstruction or colonic inertia.

[0301] In some embodiments, the pain is associated with pancreatitis or kidney stones.

[0302] In some embodiments, the pain is endometrial pain or bladder pain. In some embodiments, the pain is associated with endometriosis, interstitial cystitis or a urinary tract infection. In particular embodiments, the pain is associated with endometriosis.

[0303] The present disclosure also provides a use of a molecule of the present disclosure as an analgesic, and an analgesic comprising, consisting or consisting essentially of a molecule of the present disclosure.

[0304] Also provided, in another aspect of the present disclosure is a method of treating or at least partially inhibiting the development of anxiety in a subject, comprising administering an effective amount of the molecule of the present disclosure to the subject. In a further aspect, there is provided a use of a molecule of the present disclosure for treating or at least partially inhibiting the development of anxiety in a subject; a molecule of the present disclosure for use in treating or at least partially inhibiting the development of anxiety in a subject; or a use of a molecule of the present disclosure in the manufacture of a medicament for treating or at least partially inhibiting the development of anxiety in a subject.

[0305] In some embodiments, the subject has a disorder of the gastrointestinal tract, such as irritable bowel syndrome or inflammatory bowel disease. For example, in some embodiments, the subject has anxiety and irritable bowel syndrome or inflammatory bowel disease.

[0306] The molecules of the present disclosure are useful for inhibiting Nav1.1 and / or Nav1.7. As such, the present disclosure provides, in a further aspect, a method of antagonising Nav1.1 and / or Nav1.7, comprising contacting Nav1.1 and / or Nav1.7 with a molecule of the present disclosure. Also provided is a use of a molecule of the present disclosure for antagonising Nav1.1 and / or Nav1.7; a molecule of the present disclosure for use in antagonising Nav1.1 and / or Nav1.7; and a use of a molecule of the present disclosure in the manufacture of a medicament for antagonising Nav1.1 and / or Nav1.7.

[0307] In some embodiments, the methods and uses comprise contacting a cell expressing Nav1.1 and / or Nav1.7 with a molecule of the present disclosure. Suitable cells include, but are not limited to, a vertebrate cell, particularly a mammalian or avian cell, especially a mammalian cell, that expresses at least one Nav1.1 and / or Nav1.7 channel. The cell may be a vertebrate cell, such as a primate cell; an avian cell; a livestock animal cell such as a sheep cell, cow cell, horse cell, deer cell, donkey cell and pig cell; a laboratory test animal cell such as a rabbit cell, mouse cell, rat cell, guinea pig cell and hamster cell; a companion animal cell such as a cat cell and dog cell; and a captive wild animal cell such as a fox cell, deer cell and dingo cell. In particular embodiments, the Nav1.1 and / or Nav1.7 expressing cell is a human cell. In specific embodiments, the Nav1.1 and / or Nav1.7 expressing cell is a neuronal cell, especially a sensory or sympathetic neuron or an interneuron (e.g. an inhibitory interneuron), most especially a sensory neuron such as a nociceptor.

[0308] In specific embodiments, the molecules of the present disclosure inhibit Nav1.1 and Nav1.7.

[0309] In a further aspect of the present disclosure, there is provided a method of inhibiting an activity of Nav1.1 and / or Nav1.7, comprising contacting Nav1.1 and / or Nav1.7 with a molecule of the present disclosure. Also provided is a use of a molecule of the present disclosure for inhibiting an activity of Nav1.1 and / or Nav1.7; a molecule of the present disclosure for use in inhibiting an activity of Nav1.1 and / or Nav1.7; and a use of a molecule of the present disclosure in the manufacture of a medicament for inhibiting an activity of Nav1.1 and / or Nav1.7

[0310] In some embodiments, the methods and uses comprise contacting a cell expressing Nav1.1 and / or Nav1.7 with a molecule of the present disclosure. Suitable cells are discussed supra.

[0311] In specific embodiments, the molecules of the present disclosure inhibit an activity of Nav1.1 and Nav1.7.

[0312] The methods may involve inhibiting one or more activities of Nav1.1 and / or Nav1.7 including, but not limited to, the transport of sodium ions across a cellular membrane, activation of the channel, movement of the voltage sensor into the open channel conformation, propagation of an action potential and / or cellular depolarisation.

[0313] In any one of the aspects described above, the Nav channel is preferably a human channel (e.g. hNav1.1-hNav1.9), such as hNav1.1, hNav1.7 or hNav1.6.

[0314] Any one of the methods and uses described above may involve administration of an effective amount of the molecule of the present disclosure as described in Section 4 supra. The molecule of the present disclosure may be administered via anysuitable route of administration, such as oral, rectal, topical, intranasal, intraocular, transmucosal, intestinal, enteral, intramuscular, subcutaneous, intramedullary, intrathecal, intraventricular, intracerebral, intravaginal, intravesical, intravenous or intraperitoneal administration; especially oral, intravenous, intramuscular, subcutaneous, intrathecal or intraperitoneal administration. In particular embodiments, the molecule of the present disclosure is administered via oral administration.

[0315] The dosage and frequency will depend on the subject, the condition, disease or disorder to be treated and the route of administration. A skilled person will readily be able to determine suitable dosages and frequency of such dosages. For example, the molecule may be administered in an amount in the range of from about 0.25 μg to about 2000 mg. The dosage to be administered to the subject may, alternatively, be calculated based on the body weight of the subject. In some embodiments, the molecule may be administered in an amount in the range of from about 0.01 µg / kg body weight to about 100 µg / kg body weight (and all one-hundredth integers therebetween), about 0.01 µg / kg body weight to about 10 µg / kg body weight, about 0.01 µg / kg body weight to about 1 µg / kg body weight, about 0.1 µg / kg body weight to about 100 µg / kg body weight, about 0.1 µg / kg body weight to about 10 µg / kg body weight, about 0.1 µg / kg body weight to about 1 µg / kg body weight, or about 10 µg / kg body weight to about 100 µg / kg body weight. The molecule may be administered at a frequency of, for example, once daily, or twice or three times daily. The treatment may be continued for multiple days, weeks, months or years. In embodiments where the pharmaceutical composition comprises one or more additional active ingredients, the dosages and frequency of administration are determined by reference to the usual dose and manner of administration of the said ingredients.

[0316] Any one of the methods or uses described above may, in some embodiments, involve the administration of one or more further active agents as described in Section 4 supra, such as an anti-inflammatory agent, analgesic, anaesthetic and / or an inflammatory bowel disease, irritable bowel syndrome or gastric motility disorder treatment.

[0317] A skilled person will be well aware of suitable assays used to evaluate the antagonism or inhibition of Nav1.1 and Nav1.7. For example, the method may include contacting Nav1.1 or Nav1.7 or a subunit thereof (e.g. immobilised Nav1.1 or Nav1.7 or a subunit thereof, such as the extracellular domain) with a molecule of the present disclosure and assessing the binding affinity. Alternatively, the method may include screening for the inhibition of the activity, presence or expression of a downstream cellular target or product, or a downstream effect, such as a sodium ion current, action potential propagation or cellular depolarisation. Detecting such inhibition may be achieved utilising techniquesincluding, but not limited to, ELISA, a binding assay (e.g. a radioligand binding assay or fluorescence binding assay), nuclear magnetic resonance, protein-ligand structure determination techniques (e.g. protein x-ray crystallography or cryogenic electron microscopy), surface plasmon resonance, immunofluorescence, Western blots, immunoprecipitation, immunostaining, scintillation proximity assays, competitive inhibition assays, a colorimetric assay, electrophysiology or a membrane potential assay (e.g. a fluorescence imaging plate reader (FLIPR) assay, such as the assays described in WO 2012 / 162731 A1, the entire content of which is incorporated by reference herein). In particular embodiments, antagonism and / or inhibition of Nav1.1 and Nav1.7 are determined using automated whole-cell patch-clamp electrophysiology (e.g. using a Sophion QPatch 16X platform) with HEK 293 cells stably co-expressing the relevant human NaV subtypes and the human β1 auxiliary subunit. Cells are maintained at a holding potential –80 mV and Na+currents are elicited by 20-ms voltage steps to 0 mV from a –120 mV conditioning pulse applied for 200 ms. To obtain the concentration–response curves and calculate the IC50, cells maintained at the holding potential are incubated at each dose of the molecule of the present disclosure for 5 mins with increasing concentrations of the molecule. The IC50values are then obtained by fitting a Hill equation with variable slope to concentration– response curves via linear regression, using a suitable program, such as Prism (GraphPad Software, San Diego, CA, USA).

[0318] Suitable assays are also described in, for example, Kaczorowski, et al. (2011) Frontiers in Pharmacology, 2(78): 1-11; Cardoso, et al. (2015) Mol Pharmacol, 88(2): 291-303; Felix, et al. (2004) Assay Drug Dev Technol, 2: 260-268; Deuis, et al., (2016) Toxins, 8(3): 78; Salvatierra, et al. (2018) JCI Insight, 3(11): e121000; Gilchrist et al. (2014) ACS Chem Biol, 9: 1204-1212; and Deuis et al. (2017) Scientific Reports, 7: 40883. 6. Methods of Identification

[0319] This disclosure also encompasses the use of the molecule of the present disclosure in assays for identifying Nav1.1 and / or Nav1.7 modulators (e.g. inhibitors) and agents for the treatment of abdominal pain.

[0320] As such, in a further aspect, there is provided a use of a molecule of the present disclosure for detecting the binding of a candidate agent to Nav1.1 and / or Nav1.7. Further provided is a use of a molecule of the present disclosure for detecting the ability of a candidate agent to inhibit an activity of Nav1.1 and / or Nav1.7.

[0321] Also provided is a method of identifying an agent that binds to Nav1.1 and / or Nav1.7, the method comprising:contacting a preparation with a candidate agent and a molecule of the present disclosure, wherein the preparation comprises a polypeptide comprising an amino acid sequence corresponding to Nav1.1 and / or Nav1.7 or a fragment thereof; and detecting a change in the binding of the molecule of the present disclosure to Nav1.1 and / or Nav1.7 or a fragment thereof relative to the binding of the molecule in the absence of the candidate agent, wherein the change indicates that the candidate agent binds to Nav1.1 and / or Nav1.7.

[0322] In some embodiments, the fragment of Nav1.1 and / or Nav1.7 is a biologically active fragment. In some embodiments, the fragment of Nav1.1 and / or Nav1.7 is a subunit of Nav1.1 and / or Nav1.7 (e.g. the α and / or the β1, β2, β3 and / or β4 subunits; especially the α subunit), the extracellular domain of Nav1.1 and / or Nav1.7 or pore of Nav1.1 and / or Nav1.7.

[0323] While the change in the binding of the molecule may be detected directly (e.g. using a labelled molecule of the present disclosure), in some embodiments, the change in the binding of the molecule is determined indirectly. In such embodiments, the change in the binding of the molecule is determined by determining a change in Nav1.1 and / or Nav1.7 activity, such as one or more of transport of sodium ions across a cellular membrane, activation of the channel, movement of the voltage sensor into the open channel conformation, propagation of an action potential and / or cellular depolarisation.

[0324] A skilled person will be well aware of suitable preparations. Exemplary preparations include, but are not limited to, a cell (e.g. a HEK cell, an SHSY5Y cell, an ovary, a bacterial cell, an insect cell), a membrane or a solid support (e.g. a microtiter plate, a chip and the like).

[0325] Usually, various predetermined concentrations of candidate agents are used for screening, such as 0.01 μM, 0.1 μM, 1 μM and 10 μM.

[0326] The inventors have also conceived that molecules which selectively inhibit Nav1.1 and Nav1.7 over Nav1.6 will be useful for treating or inhibiting the development of abdominal pain. Accordingly, in another aspect, there is provided a method of identifying an agent for the treatment of abdominal pain, the method comprising: providing a candidate agent; determining whether the candidate agent has a voltage-gated sodium channel inhibitory profile, wherein the inhibitory profile is characterised by an IC50 of 100 nM or less for Nav1.1 and Nav1.7, and an IC50 for Nav1.1 at least two-fold lower than the IC50 for Nav1.6; and identifying the candidate agent as an agent for the treatment of abdominal pain.

[0327] In some embodiments, the candidate agent comprises, consists or consists essentially of an amino acid sequence that is distinguished from the amino acid sequence of SEQ ID NO: 1 by at least one amino acid modification: NDCLGFWSACNPKNDKCCANLVCSSKHKWCKGKL [SEQ ID NO: 1].

[0328] In particular embodiments, the candidate agent is a proteinaceous molecule or a peptide. In some embodiments, the candidate agent has less than about 97%, 96%, 95%, 94%, 93%, 92%, 91%, 90%, 85%, 80%, 70%, 60%, 50%, 40%, 30%, 20% or 10% amino acid sequence identity to the amino acid sequence of SEQ ID NO: 1.

[0329] In particular embodiments, the candidate agent is distinguished from the amino acid sequence of SEQ ID NO: 1 by at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 amino acid modifications. Suitable amino acid modifications include, but are not limited to, an amino acid substitution, an amino acid addition or an amino acid deletion.

[0330] In some embodiments, the candidate agent is distinguished from the amino acid sequence of SEQ ID NO: 1 by deletion or addition of one or more amino acids (such as from 1-50 amino acid residues and all integer amino acids therebetween) to the N-terminal and / or C-terminal end of the sequence, deletion or addition of one or more amino acids (such as from 1-5 amino acid residues and all integer amino acids therebetween) at one or more sites in the sequence, or substitution of one or more amino acids at one or more sites in the sequence.

[0331] In particular embodiments, the inhibitory profile is characterised by an IC50 for Nav1.1 and Nav1.7 of 100 nM or less, 90, nM or less, 80 nM or less, 70 nM or less, 60 nM or less, 50 nM or less, 40 nM or less, 30 nM or less, 20 nM or less, 10 nM or less or 1 nM or less. In particular embodiments, the inhibitory profile is characterised by an IC50 for Nav1.1 and / or Nav1.7 at least 2-fold, 5-fold, 10-fold, 20-fold or 50-fold lower than the IC50 for Nav1.6; especially at least 2-fold lower than the IC50 for Nav1.6.

[0332] In any one of the aspects provided above, the candidate agent is suitably a proteinaceous molecule or a peptide.

[0333] The identified candidate agent may be used in any one or more of the methods or uses described in Section 5 supra. As such, the present disclosure further provides a method of treating or at least partially inhibiting the development of abdominal pain in a subject, comprising administering to the subject an effective amount of a molecule having a voltage-gated sodium channel inhibitory profile characterised by an IC50 of 100 nM or less for Nav1.1 and Nav1.7, and an IC50 for Nav1.1 at least two-fold lower than the IC50 for Nav1.6. Also contemplated by the present disclosure is a molecule having a voltage- gated sodium channel inhibitory profile characterised by an IC50 of 100 nM or less forNav1.1 and Nav1.7, and an IC50 for Nav1.1 at least two-fold lower than the IC50 for Nav1.6 for use in treating or inhibiting the development of abdominal pain in a subject; a use of a molecule having a voltage-gated sodium channel inhibitory profile characterised by an IC50of 100 nM or less for Nav1.1 and Nav1.7, and an IC50 for Nav1.1 at least two-fold lower than the IC50 for Nav1.6 for treating or inhibiting the development of abdominal pain in a subject; and a use of a molecule having a voltage-gated sodium channel inhibitory profile characterised by an IC50 of 100 nM or less for Nav1.1 and Nav1.7, and an IC50 for Nav1.1 at least two-fold lower than the IC50 for Nav1.6 in the manufacture of a medicament for treating or inhibiting the development of abdominal pain in a subject.

[0334] In some embodiments, the candidate agent comprises, consists or consists essentially of an amino acid sequence that is distinguished from the amino acid sequence of SEQ ID NO: 1 by at least one amino acid modification.

[0335] Suitable types of abdominal pain are as described in Section 5 supra.

[0336] In another aspect, there is provided an abdominal pain analgesic or an anxiolytic comprising a molecule having a voltage-gated sodium channel inhibitory profile characterised by an IC50 of 100 nM or less for Nav1.1 and Nav1.7, and an IC50 for Nav1.1 at least two-fold lower than the IC50 for Nav1.6.

[0337] Suitable types of abdominal pain are as described in Section 5.

[0338] Suitable compositions comprising the analgesic or identified candidate agent discussed in the aspects above are as described in Section 4 supra.

[0339] In specific embodiments of any one of the aspects discussed above, the molecule is a proteinaceous molecule or a peptide.

[0340] The inhibitory profile of the candidate agent or molecule (e.g. inhibition of Nav1.1, Nav1.6 and Nav1.7) in any one of the aspects described herein may be determined using assays which are routine in the art. For example, suitable assays include, but are not limited to, ELISA, a binding assay (e.g. a radioligand binding assay or fluorescence binding assay), nuclear magnetic resonance, protein-ligand structure determination techniques (e.g. protein x-ray crystallography or cryogenic electron microscopy), surface plasmon resonance, immunofluorescence, Western blots, immunoprecipitation, immunostaining, scintillation proximity assays, competitive inhibition assays, a colorimetric assay, electrophysiology or a membrane potential assay (e.g. a fluorescence imaging plate reader (FLIPR) assay); especially electrophysiology, a binding assay or a membrane potential assay. In particular embodiments of any one of the aspects described herein, the IC50 values are determined using automated whole-cell patch-clamp electrophysiology using a Sophion QPatch 16X platform with HEK 293 cells stably co- expressing the relevant human NaV subtypes and the human β1 auxiliary subunit. Cells aremaintained at a holding potential –80 mV and Na+currents are elicited by 20-ms voltage steps to 0 mV from a –120 mV conditioning pulse applied for 200 ms. To obtain the concentration–response curves and calculate the IC50, cells maintained at the holding potential are incubated at each dose of the molecule of the present disclosure for 5 mins with increasing concentrations of the molecule. The IC50 values are then obtained by fitting a Hill equation with variable slope to concentration–response curves via linear regression, using a suitable program, such as Prism (GraphPad Software, San Diego, CA, USA). The utility of the candidate agent or molecule as an agent for the treatment of abdominal pain may be confirmed in a number of ways, including the use of a suitable animal pain model in animals or testing in a human. EMBODIMENTS

[0341] Exemplary embodiments include, but are not limited to: 1. A molecule comprising an amino acid sequence represented by Formula I: CLX1X2X3X4ACNPX5NDKCCANX29VCSX6X7HX8X9C (I) wherein: X1 is a small amino acid residue or an acidic amino acid residue; X2is a hydrophobic amino acid residue or a small amino acid residue; X3 is a hydrophobic amino acid residue; X4 is a small amino acid residue; X5 is a basic amino acid residue; X6 is a small amino acid residue or a basic amino acid residue; X7 is a basic amino acid residue; X8 is a basic amino acid residue; X9 is any amino acid residue; and X29 is any amino acid residue, wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1: NDCLGFWSACNPKNDKCCANLVCSSKHKWCKGKL [SEQ ID NO: 1]. 2. The molecule according to embodiment 1, wherein: X1 is selected from A, S, G, T, D, E and modified forms thereof; X2 is selected from M, I, L, V, F, Y, W, Nle, 4-benzoyl-L-phenylalanine (Bpa), 4,4’- biphenylalanine (Bip), A, S, G, T and modified forms thereof;X3 is selected from M, I, L, V, F, Y, W, Nle and modified forms thereof; X4 is selected from A, S, G, T, homoserine (hS) and modified forms thereof; X5 is selected from R, K and modified forms thereof; X6 is selected from A, S, G, T, R, K and modified forms thereof; X7 is selected from R, K and modified forms thereof; X8 is selected from R, K, homoarginine (hR), diaminobutyric acid (Dab) and modified forms thereof; X9 is selected from M, I, L, V, F, Y, W, Nle, Bpa, Bip, A, G, S, T and modified forms thereof; and X29 is selected from M, I, L, V, F, Y, W, Nle, A, G, S, T and modified forms thereof. 3. The molecule according to embodiment 1 or embodiment 2, wherein X1 is selected from G and E. 4. The molecule according to any one of embodiments 1-3, wherein X2 is selected from F, Bip, A and Bpa. 5. The molecule according to embodiment 4, wherein X2 is Bip. 6. The molecule according to any one of embodiments 1-5, wherein X3 is W. 7. The molecule according to any one of embodiments 1-6, wherein X4 is selected from S and hS. 8. The molecule according to any one of embodiments 1-7, wherein X5 is selected from K and R. 9. The molecule according to any one of embodiments 1-8, wherein X6 is selected from K and S. 10. The molecule according to any one of embodiments 1-9, wherein X7 is selected from K and R. 11. The molecule according to any one of embodiments 1-10, wherein X8 is selected from K, R, Dab and hR. 12. The molecule according to any one of embodiments 1-11, wherein X9 is selected from W, Bpa, A and Bip. 13. The molecule according to embodiment 12, wherein X9 is A. 14. The molecule according to any one of embodiments 1-13, wherein X29 is selected from L and A. 15. The molecule according to any one of embodiments 1-14, wherein the molecule is represented by Formula II: X10X11X12CLX1X2X3X4ACNPX5NDKCCANX29VCSX6X7HX8X9CX13X14X15X16 (II) wherein:X1 to X9 and X29 are as defined in any one of embodiments 1-14; X10 is absent or is a small amino acid residue; X11 is an amide-containing amino acid residue; X12 is an acidic amino acid residue; X13 is a basic amino acid residue; X14 is a small amino acid residue; X15 is a basic amino acid residue; and X16 is a hydrophobic amino acid residue. 16. The molecule according to embodiment 15, wherein: X10 is absent or is selected from A, S, G, T and modified forms thereof; X11 is selected from N, Q and modified forms thereof; X12 is selected from D, E and modified forms thereof; X13 is selected from R, K, hR and modified forms thereof; X14 is selected from A, S, G, T and modified forms thereof; X15is selected from R, K, Ornithine (Orn) and modified forms thereof; and X16 is selected from M, I, L, V, F, Y, W, Nle and modified forms thereof. 17. The molecule according to any one of embodiments 1-16, wherein the molecule comprises, consists or consists essentially of an amino acid sequence represented by any one of SEQ ID NOs: 2-33 and 51-54: GNDCLGFWSACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 2]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 3]; GNDCLGX19WSACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 4]; GNDCLGFWX20ACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 5]; GNDCLGFWSACNPRNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 6]; GNDCLGFWSACNPKNDKCCANLVCSKKHKWCKAX17L [SEQ ID NO: 7]; GNDCLGFWSACNPKNDKCCANLVCSSKHX21WCKAX17L [SEQ ID NO: 8]; GNDCLGX19WSACNPKNDKCCANLVCSSKHX21WCKAX17L [SEQ ID NO: 9]; GNDCLGX19WX20ACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 10]; GNDCLGX19WSACNPRNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 11]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX18CKGX17L [SEQ ID NO: 12];GNDCLGFWSACNPKNDKCCANLVCSSKHKX18CKAKL [SEQ ID NO: 13]; GNDCLEFWSACNPKNDKCCANLVCSSKHKX18CX22GKL [SEQ ID NO: 14]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX18CX22GKL [SEQ ID NO: 15]; GNDCLEFWSACNPKNDKCCANLVCSSKHKWCX22GKL [SEQ ID NO: 16]; GNDCLEFWSACNPKNDKCCANLVCSSKHKX18CKGKL [SEQ ID NO: 17]; GNDCLGX18WSACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 18]; GNDCLGFWSACNPKNDKCCANLVCSSKHKWCRAX17L [SEQ ID NO: 19]; GNDCLGFWSACNPKNDKCCANLVCSSRHKWCKAX17L [SEQ ID NO: 20]; GNDCLGFWSACNPKNDKCCANLVCSSKHRWCKAX17L [SEQ ID NO: 21]; GNDCLGFWSACNPKNDKCCANLVCSSKHX22WCKAX17L [SEQ ID NO: 22]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX19CKAX17L [SEQ ID NO: 23]; GNDCLGX18WSACNPKNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 24]; GNDCLGX19WSACNPKNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 25]; GNDCLGFWX20ACNPKNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 26]; GNDCLGFWSACNPRNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 27]; GNDCLGFWSACNPKNDKCCANLVCSKKHKX18CKAX17L [SEQ ID NO: 28]; GNDCLGFWSACNPKNDKCCANLVCSSRHKX18CKAX17L [SEQ ID NO: 29]; GNDCLGFWSACNPKNDKCCANLVCSSKHRX18CKAX17L [SEQ ID NO: 30]; GNDCLGFWSACNPKNDKCCANLVCSSKHX22X18CKAX17L [SEQ ID NO: 31]; GNDCLGFWSACNPKNDKCCANLVCSSKHX21X18CKAX17L [SEQ ID NO: 32]; GNDCLGX19WSACNPKNDKCCANLVCSKKHKWCKAX17L [SEQ ID NO: 33]; GNDCLGAWSACNPKNDKCCANLVCSSKHX21WCKAX17L [SEQ ID NO: 51]; GNDCLGX19WSACNPKNDKCCANAVCSSKHX21WCKAX17L [SEQ ID NO: 52]; GNDCLGX19WSACNPKNDKCCANLVCSSKHX21ACKAX17L [SEQ ID NO: 53]; and GNDCLGX19WSACNPKNDKCCANAVCSSKHX21ACKAX17L [SEQ ID NO: 54], wherein: X17 is Orn; X18 is Bpa;X20 is hS; X21 is Dab; and X22 is hR. 18. The molecule according to embodiment 17, wherein the molecule comprises, consists or consists essentially of an amino acid sequence represented by any one of SEQ ID NOs: 2-11, 52 and 53. 19. The molecule according to any one of embodiments 1-18, wherein the six cysteine residues in the molecule are bonded in pairs to form three disulfide bonds, wherein the disulfide bonds are formed between the side chains of Cys 1 and Cys 16, Cys 8 and Cys 21, and Cys 15 and Cys 28 (numbered in accordance with the amino acid sequence of Formula I). 20. The molecule according to any one of embodiments 1-19, wherein the molecule comprises a C-terminal amide. 21. A molecule comprising an amino acid sequence represented by Formula IV: CLX1X2X3X4ACNPX5NDKCCANLVCSX6X7HX8X9C (IV) wherein: X1 is a small amino acid residue or an acidic amino acid residue; X2 is a hydrophobic amino acid residue; X3 is a hydrophobic amino acid residue; X4 is a small amino acid residue; X5 is a basic amino acid residue; X6is a small amino acid residue or a basic amino acid residue; X7 is a basic amino acid residue; X8 is a basic amino acid residue; and X9 is a hydrophobic amino acid residue; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1: NDCLGFWSACNPKNDKCCANLVCSSKHKWCKGKL [SEQ ID NO: 1]. 22. The molecule according to embodiment 21, wherein: X1 is selected from A, S, G, T, D, E and modified forms thereof; X2 is selected from M, I, L, V, F, Y, W, Nle, 4-benzoyl-L-phenylalanine (Bpa), 4,4’- biphenylalanine (Bip) and modified forms thereof;X3 is selected from M, I, L, V, F, Y, W, Nle and modified forms thereof; X4 is selected from A, S, G, T, homoserine (hS) and modified forms thereof; X5 is selected from R, K and modified forms thereof; X6 is selected from A, S, G, T, R, K and modified forms thereof; X7 is selected from R, K and modified forms thereof; X8 is selected from R, K, homoarginine (hR), diaminobutyric acid (Dab) and modified forms thereof; and X9 is selected from M, I, L, V, F, Y, W, Nle, Bpa, Bip and modified forms thereof. 23. The molecule according to embodiment 21 or embodiment 22, wherein X1 is selected from G and E. 24. The molecule according to any one of embodiments 21-23, wherein X2 is selected from F, Bip and Bpa. 25. The molecule according to any one of embodiments 21-24, wherein X3 is W. 26. The molecule according to any one of embodiments 21-25, wherein X4is selected from S and hS. 27. The molecule according to any one of embodiments 21-26, wherein X5 is selected from K and R. 28. The molecule according to any one of embodiments 21-27, wherein X6 is selected from K and S. 29. The molecule according to any one of embodiments 21-28, wherein X7 is selected from K and R. 30. The molecule according to any one of embodiments 21-29, wherein X8 is selected from K, R, Dab and hR. 31. The molecule according to any one of embodiments 21-30, wherein X9 is selected from W, Bpa and Bip. 32. The molecule according to any one of embodiments 21-31, wherein the molecule is represented by Formula V: X10X11X12CLX1X2X3X4ACNPX5NDKCCANLVCSX6X7HX8X9CX13X14X15X16(V) wherein: X1 to X9 are as defined in any one of embodiments 21-31; X10 is absent or is a small amino acid residue; X11 is an amide-containing amino acid residue; X12 is an acidic amino acid residue; X13 is a basic amino acid residue;X14 is a small amino acid residue; X15 is a basic amino acid residue; and X16 is a hydrophobic amino acid residue. 33. The molecule according to embodiment 32, wherein: X10 is absent or is selected from A, S, G, T and modified forms thereof; X11 is selected from N, Q and modified forms thereof; X12 is selected from D, E and modified forms thereof; X13 is selected from R, K, hR and modified forms thereof; X14 is selected from A, S, G, T and modified forms thereof; X15 is selected from R, K, Ornithine (Orn) and modified forms thereof; and X16 is selected from M, I, L, V, F, Y, W, Nle and modified forms thereof. 34. The molecule according to embodiment 32 or embodiment 33, wherein X10 is G. 35. The molecule according to any one of embodiments 32-34, wherein X11 is N. 36. The molecule according to any one of embodiments 32-35, wherein X12 is D. 37. The molecule according to any one of embodiments 32-36, wherein X13 is K, R or hR. 38. The molecule according to any one of embodiments 32-37, wherein X14 is A or G. 39. The molecule according to any one of embodiments 32-38, wherein X15 is K or Orn. 40. The molecule according to any one of embodiments 32-39, wherein X16 is L. 41. The molecule according to any one of embodiments 21-40, wherein the molecule is represented by Formula VI: GNDCLGX2WX4ACNPX5NDKCCANLVCSSKHX8X9CKAX15L (VI) wherein: X2, X4, X5, X8 and X9 are as defined in any one of embodiments 21, 22, 24, 26, 27, 30 and 31; and X15 is Orn. 42. The molecule according to embodiment 41, wherein: X2is F or Bip; X4 is S or hS; X5 is K or R; X8 is K or Dab; and / or X9 is W or Bpa.43. The molecule according to any one of embodiments 21-42, wherein the molecule comprises, consists or consists essentially of an amino acid sequence represented by any one of SEQ ID NOs: 2-33. 44. The molecule according to embodiment 43, wherein the molecule comprises, consists or consists essentially of an amino acid sequence represented by any one of SEQ ID NOs: 2-11. 45. The molecule according to embodiment 43, wherein the molecule comprises, consists or consists essentially of an amino acid sequence represented by SEQ ID NO: 9. 46. The molecule according to any one of embodiments 21-45, wherein the six cysteine residues in the molecule are bonded in pairs to form three disulfide bonds. 47. The molecule according to embodiment 46, wherein the disulfide bonds are formed between the side chains of Cys 1 and Cys 16, Cys 8 and Cys 21, and Cys 15 and Cys 28 (numbered in accordance with the amino acid sequence of Formula I). 48. The molecule according to any one of embodiments 21-47, wherein the molecule comprises a C-terminal amide. 49. A molecule comprising an amino acid sequence represented by Formula VII: X23LX1X2X3X4AX24NPX5NDKX25X26ANLVX27SX6X7HX8X9X28(VII) wherein: X1 to X9 are as defined in any one of embodiments 21-42; X23 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X26; X24 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X27; X25 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X28; X26 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X23; X27is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X24; X28 is an amino acid residue having a side chain that forms a covalent cross-link with the side chain of X25; wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1: NDCLGFWSACNPKNDKCCANLVCSSKHKWCKGKL [SEQ ID NO: 1].50. The molecule according to embodiment 49, wherein the covalent cross-link between X23 and X26, X24 and X27 and X25 and X28 are independently selected from the group consisting of a disulfide bond, a diselenide bond, a lanthionine bridge, an amide bond, an ester linkage, a thioester linkage, a carbamoyl linkage, an alkyl linkage, an alkenyl linkage, an ether linkage, a thioether linkage, an amine linkage and a thioamide linkage. 51. The molecule according to embodiment 49 or embodiment 50, wherein X23 to X28 are independently selected from the group consisting of C, K, R, D, E, penicillamine, selenocysteine, diaminopropionic acid, mercaptoproline and modified forms thereof. 52. The molecule according to any one of embodiments 1-51, wherein the molecule exhibits Nav1.1 and / or Nav1.7 selectivity of greater than about 50-fold with respect to antagonism of Nav1.6. 53. A composition comprising, consisting or consisting essentially of a molecule according to any one of embodiments 1-52 and a pharmaceutically acceptable excipient. 54. A molecule according to any one of embodiments 1-52 for use in therapy. 55. A method of treating or at least partially inhibiting the development of a condition in which inhibiting Nav1.1 and / or Nav1.7 activity is associated with effective treatment or inhibition of the condition, comprising administering an effective amount of the molecule according to any one of embodiments 1-52. 56. The method according to embodiment 55, wherein the condition is pain. 57. The method according to embodiment 56, wherein the pain is selected from the group consisting of inflammatory pain, visceral pain, abdominal pain and nociceptive pain. 58. The method according to embodiment 57, wherein the pain is visceral pain. 59. The method according to embodiment 57, wherein the pain is abdominal pain. 60. The method according to any one of embodiments 57-59, wherein the pain is associated with irritable bowel syndrome, inflammatory bowel disease, gastrointestinal inflammation, or a gastric motility disorder. 61. The method according to embodiment 60, wherein the gastric motility disorder is gastroparesis, functional dyspepsia, cannabis hyperemesis syndrome, chronic intestinal pseudo-obstruction or colonic inertia. 62. The method according to embodiment 56, wherein the pain is migraine pain. 63. The method according to any one of embodiments 56-62, wherein the pain is chronic pain. 64. The method according to any one of embodiments 55-63, wherein the molecule does not have a substantial effect on gastric motility. 65. The method according to embodiment 55, wherein the condition is anxiety. 66. A method of treating or at least partially inhibiting the development of pain in a subject, comprising administering an effective amount of the molecule according to any one of embodiments 1-52 to the subject.67. The method according to embodiment 66, wherein the pain is chronic pain. 68. The method according to embodiment 66 or embodiment 67, wherein the pain is selected from the group consisting of inflammatory pain, mechanical pain, visceral pain, abdominal pain and nociceptive pain. 69. The method according to embodiment 68, wherein the pain is visceral pain. 70. The method according to embodiment 68, wherein the pain is abdominal pain. 71. The method according to any one of embodiments 68-70, wherein the pain is associated with irritable bowel syndrome, inflammatory bowel disease, gastrointestinal inflammation or a gastric motility disorder. 72. The method according to embodiment 71, wherein the gastric motility disorder is gastroparesis, functional dyspepsia, cannabis hyperemesis syndrome, chronic intestinal pseudo-obstruction or colonic inertia. 73. The method according to embodiment 66 or embodiment 67, wherein the pain is migraine pain. 74. The method according to embodiment 66 or embodiment 67, wherein the pain is abdominal pain, endometrial pain or bladder pain. 75. The method according to any one of embodiments 66, 67 and 74, wherein the pain is associated with irritable bowel syndrome, inflammatory bowel disease, gastrointestinal inflammation, a gastric motility disorder, endometriosis or a urinary tract infection. 76. A method of antagonising Nav1.1 and / or Nav1.7, comprising contacting Nav1.1 and / or Nav1.7 with a molecule according to any one of embodiments 1-52. 77. Use of a molecule according to any one of embodiments 1-52 as an analgesic. 78. Use of a molecule according to any one of embodiments 1-52 for detecting the binding of a candidate agent to Nav1.1 and / or Nav1.7. 79. A method of identifying an agent that binds to Nav1.1 and / or Nav1.7, the method comprising: contacting a preparation with a candidate agent and a molecule according to any one of embodiments 1-52, wherein the preparation comprises a polypeptide comprising an amino acid sequence corresponding to Nav1.1 and / or Nav1.7 or a fragment thereof; and detecting a change in the binding of the molecule according to any one of embodiments 1- 52 to Nav1.1 and / or Nav1.7 or a fragment thereof relative to the binding of the molecule of any one of embodiments 1-51 in the absence of the candidate agent, wherein the change indicates that the candidate agent binds to Nav1.1 and / or Nav1.7. 80. A method of identifying an agent for the treatment of abdominal pain, the method comprising: providing a candidate agent;determining whether the candidate agent has a voltage-gated sodium channel inhibitory profile, wherein the inhibitory profile is characterised by an IC50 of 100 nM or less for Nav1.1 and Nav1.7, and an IC50for Nav1.1 at least two-fold lower than the IC50for Nav1.6; and identifying the candidate agent as an agent for the treatment of abdominal pain. 81. The method according to embodiment 80, wherein the candidate agent comprises, consists or consists essentially of an amino acid sequence that is distinguished from the amino acid sequence of SEQ ID NO: 1 by at least one amino acid modification: NDCLGFWSACNPKNDKCCANLVCSSKHKWCKGKL [SEQ ID NO: 1]. 82. The method according to embodiment 81, wherein the amino acid modification(s) is selected from the group consisting of an amino acid substitution, an amino acid addition or an amino acid deletion. 83. A method of treating or at least partially inhibiting the development of abdominal pain in a subject, comprising administering to the subject an effective amount of a molecule having a voltage-gated sodium channel inhibitory profile characterised by an IC50 of 100 nM or less for Nav1.1 and Nav1.7, and an IC50 for Nav1.1 at least two-fold lower than the IC50 for Nav1.6. 84. The method according to embodiment 83, wherein the molecule comprises, consists or consists essentially of an amino acid sequence that is distinguished from the amino acid sequence of SEQ ID NO: 1 by at least one amino acid modification: NDCLGFWSACNPKNDKCCANLVCSSKHKWCKGKL [SEQ ID NO: 1]. 85. An abdominal pain analgesic comprising a molecule having a voltage-gated sodium channel inhibitory profile characterised by an IC50 of 100 nM or less for Nav1.1 and Nav1.7, and an IC50 for Nav1.1 at least two-fold lower than the IC50 for Nav1.6. 86. The abdominal pain analgesic according to embodiment 85, wherein the molecule comprises, consists or consists essentially of an amino acid sequence that is distinguished from the amino acid sequence of SEQ ID NO: 1 by at least one amino acid modification: NDCLGFWSACNPKNDKCCANLVCSSKHKWCKGKL [SEQ ID NO: 1].

[0342] In order that the invention may be readily understood and put into practical effect, particular preferred embodiments will now be described by way of the following non-limiting examples.EXAMPLES

[0343] All amino acids, chemicals and reagents used are commercially available from, for example, Iris Biotech GmbH (Marktredwitz, Germany) or Sigma Aldrich, Inc. (Merck KGaA, Darmstadt, Germany) and were obtained from commercial sources unless otherwise specified. EXAMPLE 1 – MOLECULAR DOCKING Materials and Methods

[0344] Hs1a analogues were designed on the basis of molecular docking studies and are presented in Table 4. In brief, Modeller 10.2 was used to develop homology models of Hs1a analogues bound to Nav1.1, Nav1.6 and Nav1.7 using the published cryo-EM structure of HwTx4 bound to a Nav1.7-NavAB chimera (PDB 7k48) and the published NMR structure of Hs1a (PDB 2mt7) as templates. The models were then refined using molecular dynamics (MD) simulations. MD simulations were run for 200 ns with channels embedded in a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) / 1-palmitoyl-2- oleoylphosphatidylethanolamine (POPE) (80 / 20) membrane and explicit water solvent. The force fields used were ff19SB (protein), Lipid19 (lipids) and OPC (water). Amber20 was used to run the simulations, which were repeated several times. The criterion for success was similarity to voltage-sensor domain II (VSD2) in 7k48. TABLE 4 SEQUENCES OF HS1A ANALOGUES Peptide Sequence SEQ ID NOM4 S25KGNDCLGFWSACNPKNDKCCANLVCSKKHKWCKA[Orn]L-NH243M4 K28Dab- GNDCLGFWSACNPKNDKCCANLVCSSKH[Dab]WCKA[Orn]L-NH244Results

[0345] Candidate peptides containing the substitution K28Dab are predicted to have favourable electrostatic interactions with D760 in NaV1.1 and E760 in NaV1.7, and a potentially repulsive interaction with H764 in NaV1.6 (exemplified with M6-NH2 in Figure 1C). In NaV1.1 and NaV1.7, K28Dab is also likely to interact with lipid headgroups in the lipid membrane. Experimentally, substitution of K28 with Dab in M4 F6Bip-NH2 improved activity 3-fold on NaV1.1, while activity on NaV1.7 and NaV1.6 were unaffected. This may be explained by the shorter sidechain of N compared to E, for NaV1.1 and NaV1.7 respectively.

[0346] Candidate peptides containing the substitution K33Orn are predicted to make a favourable interaction with the sidechain of E818 in NaV1.1 and NaV1.7 (exemplified with M6-NH2 in Figure 1D), but this interaction does not appear to be present in NaV1.6 due to a shift in binding mode. Experimentally, substitution of K33 with Orn increased activity on both NaV1.1 and NaV1.7, with minimal change to NaV1.6 activity.

[0347] Hydrophobic interactions of candidate peptides containing the substitution F6Bip are predicted to occur with the aliphatic parts of the phospholipid membrane (exemplified with M6-NH2 in Figure 2). Furthermore, in NaV1.7 an additional hydrophobic interaction is predicted with F813, and for NaV1.6, a repulsive interaction is predicted with S813 (also exemplified with M6-NH2 in Figure 1B). Experimentally, F6Bip greatly improved activity on NaV1.1 and NaV1.7, with a slight loss of activity on NaV1.6.

[0348] In MD studies with Nav1.7 embedded in membrane phospholipids, candidate peptides containing the substitution G32A are predicted to make favoured hydrophobic interactions with F813 and L814. In Nav1.1, these same positions are occupiedby G813 and L814 which are lesser but still predominantly hydrophobic, but in Nav1.6 these positions are occupied by S813 and L814 which together confers lesser hydrophobicity and hence interactions did not benefit from the substitution G32A.

[0349] It was observed from the M6-NH2 MD study that K13R would have favoured electrostatic interactions with the negatively charged residues E760 and E761 in Nav1.7, and D760 in Nav1.1, while in Nav1.6 these positions are occupied by neutral residues P760 and Q761.

[0350] In MD studies with Nav1.7 embedded in membrane phospholipids, the M6- NH2 C-terminal amide is predicted to make favoured electrostatic interactions with the negatively charged head groups of membrane phospholipids and positioned the C-terminal deeper into the membrane and closer to the VSD2, favouring hydrophobic interactions such as between M6-NH2 A33 and Nav1.7 L814.

[0351] An overview of the proposed interactions between amino acid residues in the Hs1a analogue, M6, and human Nav channels is shown in Table 5, while an overview of additional proposed interactions with amino acid residues of other Hs1a mutants and human Nav channels is shown in Table 6. In addition to mutant peptide design from MD visualisations of predicted binding interactions, further consideration was also given to the peptide-protein binding interactions of venom-derived peptides with a high degree of sequence similarity to Hs1a, including Huwentoxin-IV (HwTx-IV). Designed analogues are presented in Table 4.

[0352] Given the sequence similarity between the domain II voltage sensor (VSD2) of the different NaV subtypes, homology modelling and molecular dynamics simulations with Hs1a were utilised to identify the amino acid residues (positions) responsible for peptide interactions with VSD2 of either NaV1.1, NaV1.7 or NaV1.6. These models provided insights into which positions could be modified to maintain or improve inhibitory activity on NaV1.1 and NaV1.7, while reducing inhibitory activity on NaV1.6. Key positions which appeared important for inhibitory activity included (but were not limited to) F6, K28, and K33 on native Hs1a. The peptide residue F6 was identified as a position whereby a larger hydrophobic residue could be introduced to improve peptide:membrane and peptide:channel hydrophobic interactions selectively in NaV1.1 and NaV1.7. Positions 28 and 33 were also identified and subsequently modified with residues containing basic short side-chain residues to reduce activity on NaV1.6. Promising analogues from these in silico experiments were subsequently produced and tested in vitro resulting in the lead candidate compounds.SecM n O) ,Ra51.8.58.9.27.de, - -3,1. - -graTtSsiÅ( ,3 5 54.9.5 h G D 4 3ch N Aitw NI 6. , , , s1 4 234 1 43,24 6 n 6 V 1 111 6 56- -11 1- - ioS an N noiormedecmedec edecmmedecSommrOIo Tittc f tC a Aarcoene t one one t t oneVImo t teta i mtuceimtu mtucecemtuxT hceceerR R EetrDceqerDceqec qe irDirDc qewirDirD g TNni ir sDVI ir seDVI ir seDVI ir sDVIIHesoh YtE K dnicicicDEetoitbob ticticicicicicichitT hohr atattat botat botattat wRci ca O d Perp plasos shshs srororporpororloPretorodroydPytcltecltecorle dytcorle dytclteclmeyU PnSIH H E E E H E H E EP-iaYvL - LdA 6eTlNMn 8aininiom E MIi2 6 9 3n reHip7 5 6eR u N W 2 S 2 7 K 2 2 ba2 13 23 3 nrmtraid teEP d B H D W K A Oet- dsXisCmaE eecR n atisDecn a)tA / A / 9.siÅ(N N 5 D . 6.6.1 1 1V- -67H D NeAcS n)EA / A / 5.UatsiÅ(N N 5 GOL D A N AA1.1 06 3 6 1S V - 6 ELa 7 D 7 N BHN N A E T E WTEx xB d TyS egTygxTyg Nrv wolwolwoloirH / oHoHoOITfe gmo / gm / gmAeld ninionioC R anmlolehll hll hE neooirfdoc een doc edecTNittc ene oneI aarmtu mtu mu YE ReKtceqeDni ic qe tqerseis ceisE DVIrDVIrDVITR OicicicPtP natU dtattatS-etoi sos sro oYLcitctL dar c rAltrteclecleTeretE N P EnI / rE l / E / arlarlIo o aM oRP P PEPXtE nin asetue u di8 3 5 dismtS 1 2 ap K S e1e Rsp HEXAMPLE 2 – ACTIVITY OF ANALOGUES AT VOLTAGE-GATED SODIUM CHANNELS Materials and Methods

[0353] The Hs1a analogues (refer to Table 4) were synthesised using automated Fmoc solid-phase peptide synthesis. Wild-type Hs1a (Hs1a WT) was also synthesised with the following amino acid sequence (NDCLGFWSACNPKNDKCCANLVCSSKHKWCKGKL-OH; SEQ ID NO: 50). Peptide backbones were assembled on a Liberty PRIMETMmicrowave synthesiser (CEM Corporation, Matthews, USA) at 0.1 mmol scale with either ProTideTMrink amide or Wang resin. Peptides were cleaved from the resin by incubation in cleavage buffer (92.5% trifluoroacetic acid (TFA), 2.5% MilliQ H2O, 2.5% 3,6-dioxa-1,8- octanedithiol, 2.5% triisopropylsilane) for 40 min at 40°C. Cleaved peptides were removed from cleavage buffer through precipitation in ice-cold diethyl ether and subsequently purified via reversed-phase high-performance liquid chromatography (RP-HPLC) using a Zorbax 300SB C18 column (5 μm particle size, 21.2 x 150 mm; Agilent Technologies, Santa Clara, USA) under acidic conditions. Peaks containing the peptide of interest were identified using electrospray ionization mass spectrometry (ESI-MS) and those with correct mass were lyophilised prior to oxidation. Crude reduced peptides were dissolved in a small volume of 6 M guanidinium hydrochloride and placed in a redox buffer (100 mM Na2HPO4, 100 mM NaCl, 5 mM reduced glutathione, 0.5 mM oxidized glutathione, pH 8; final peptide concentration 0.33 mg / mL), then peptides were allowed to oxidise overnight at room temperature. The reaction was monitored via liquid chromatography coupled tandem mass spectrometry (LC-MS / MS), with a shift in peak elution time and a ~6 Dalton reduction in mass indicating successful disulfide bond formation. Crude oxidised peptide was purified via RP-HPLC as described above, with quality control performed on an analytical C18 column (Aeris Widepore XB-C18, 3.6 μm particle size, 200 Å pore size; 2.1 x 100 mm; Phenomenex, Torrance, USA) to determine purity of final products. In general, synthetic, oxidised peptides were purified to a purity of >95% by RP-HPLC.

[0354] The activity of the Hs1a analogues was examined against NaV1.1 NaV1.7, NaV1.4, NaV1.5 and NaV1.6. The pharmacological properties of the Hs1a analogues were evaluated using automated whole-cell patch-clamp electrophysiology using a Sophion QPatch 16X platform with HEK 293 cells (SB Drug Discovery, Glasgow, UK) stably co- expressing one of the human NaV subtypes and the human β1 auxiliary subunit. Cells were maintained at a holding potential –80 mV and Na+currents elicited by 20-ms voltage steps to 0 mV from a –120 mV conditioning pulse applied for 200 ms. To obtain concentration– response curves, cells maintained at the holding potential were incubated at each dose for 5 min with increasing concentrations of Hs1a analogue. IC50 values were obtained by fitting a Hill equation with variable slope to concentration–response curves via linear regression using Prism v.8 (GraphPad Software, San Diego, CA, USA).Results

[0355] The activity of the Hs1a analogues is presented in Table 7. Data are presented as mean ± standard error of the mean (SEM) based on N independent experiments in Table 7. The concentration-response curve for M6-NH2 is presented in Figure 3. The Hs1a analogues were found to be potent inhibitors of Nav1.7 and Nav1.1, with decreased activity at Nav1.6.

[0356] The overall goal of the structure-activity relationship study was to identify a candidate molecule with at least comparable (but preferably improved) inhibitory activity to wild-type Hs1a for NaV1.1 and NaV1.7, but with reduced inhibitory activity for NaV1.6. In this initial structure-activity relationship study, wild-type Hs1a was compared to other previously described inhibitory NaV peptides via sequence alignments. This facilitated the identification of several key residues, leading to the generation of single mutants including, but not limited to, W29Bpa, G32A, K33Orn and C-terminal amidation. In an effort to exploit additive combinatorial effects, several single mutants were combined, which led to the generation of the peptides M4-NH2 (SEQ ID NO: 35) and M5-NH2 (SEQ ID NO: 37). M4- NH2 was identified as a lead candidate as it selectively exhibited reduced inhibitory activity for NaV1.6, and gained inhibitory activity on NaV1.7, while NaV1.1 inhibitory activity remained the same compared to the C-terminal amidated wild-type Hs1a peptide. The peptide M5-NH2 was identified as a lead candidate as it exhibited substantially reduced inhibitory activity against NaV1.6 but only a minor reduction in inhibitory activity against NaV1.1 and NaV1.7. Following this, NaV VSD II homology models were generated and extensive molecular dynamics simulations were performed to identify additional residues (compared to those in M4-NH2 and M5-NH2) that might be amenable to substitution. Subsequently, residues at positions 6, 8, 13, 25, 26, 28, and 29 were identified as key residues to modify. Following this secondary structure-activity relationship study, the peptide M4 F6Bip-NH2 (SEQ ID NO: 39) was identified as a lead candidate due to a significant improvement in inhibitory activity for NaV1.1 and NaV1.7 but only a minor improvement in inhibitory activity for NaV1.6. A subsequent structure-activity relationship screen was based off M4 F6Bip-NH2, which led to identification of the peptide M4 F6Bip K28Dab-NH2 (M6-NH2; SEQ ID NO 46) which exhibited increased, selective inhibitory activity on NaV1.7. Overall, M6-NH2 was identified as the lead candidate, exhibiting 83-fold selectivity for inhibitory activity of NaV1.1 over NaV1.6, and a 19-fold selectivity for inhibitory activity of NaV1.7 over NaV1.6.

[0357] Given the inhibitory activity for wild-type Hs1a (SEQ ID NO: 1) (as IC50 values) ranged from 43-67 nM for NaV1.1 and NaV1.7, it was preferable that the inhibitory activity of any lead candidates exhibited comparable inhibitory activity for NaV1.1 and NaV1.7, and therefore the IC50 value for said lead candidate not be greater than 100 nM for either of NaV1.1 or NaV1.7. Additionally, selective inhibitory activity for any leadcandidates over NaV1.1 was preferred over NaV1.6. Therefore, it was preferable that any lead candidates exhibited at least 2-fold greater inhibitory activity for NaV1.1 over NaV1.6.N 5 5 5 - 5 5- - - -5- - -DET 1 A β MEananan d nanan d n d n d n dan d d d M5.S n n n n OT 1V U A a 0 0 0 0 N 05 00 00 0 0 00 00 G h 0 0 0 d 0 0 d d d d 0 d d d NICIS 1 1 01 n 01 01 n n n n 01 n n n U > > > > > > S 5 5 5 - 5 5 5A EL V SEa S M P N 05 4 3 2 2 O M h 6 2 5 18.60 245.5 218.82.5.R A F LCI1 1 6 1 3 4 3 .leSC- 2 2 2 2 2 2 2 2 2 2 2 b E H -mrH H H H H H H H H H a U C G T C O N H N H N O H N N H N N N O N NcilO AetN p L p APL N L)atAE DC-nr on N E O3) )= A L O 3nrA HKOba ) an 1,3 D S W A 8ba ;H 2 3 E 3K2 2 D K 8 S Rd3eIG,Hba ,2 h K 8 1inVe T TA d1iW- A G,a2NipS R KipS m 3 -ipB h 3 5 D Nt6 8 1 2 8 B,ip,K,repa1apB G 9,B6F S K S26KF i,BpBip tBeF es1s2F4 4 4 46F6 6dOP Y H H W1- M M M M 4 4,F toIG 4 M M 4FT,(M(4 4nVI1- 2 2 M M M T H H(6=d C G A(2N-N- n 4 6 M:E H M M n H TN-ie5reM h wEXAMPLE 3 – IN VIVO ACTIVITY IN A PRECLINICAL COLONIC HYPERSENSITIVITY MODEL Materials and Methods Animals

[0358] All experiments were performed in accordance with the guidelines of the Animal Ethics Committees of the South Australian Health and Medical Research Institute (SAHMRI) and Flinders University. Male C57BL / 6 mice were used in all experiments. These experiments conformed to the relevant regulatory standards and the ARRIVE guidelines. Male C57BL / 6 mice at 10–13 weeks of age were used in all experiments. Mice were acquired from an in-house C57BL / 6J breeding program (JAX strain #000664; originally purchased from The Jackson Laboratory (breeding barn MP14; Bar Harbor, ME; USA)) within SAHMRI's specific and opportunistic pathogen-free animal care facility. Mice were group-housed (maximum five mice per cage) on individual ventilated cages (IVC), which were filled with coarse chip dust-free aspen bedding (PURA®; Cat# ASPJMAEB-CA, PuraBed, Niederglatt, Switzerland). These cages were stored on IVC racks in specific housing rooms within a temperature-controlled environment of 22°C and a 12 h light / 12 h dark cycle. Mice had free access to LabDiet^JL Rat and Mouse / Auto6F chow (Cat# 5K52, St Louis, MO; USA) and autoclaved reverse osmosis purified water. Mouse Model of Chronic Visceral Hypersensitivity (CVH)

[0359] Colitis was induced by administration of dinitrobenzene sulfonic acid (DNBS) as described previously (Osteen et al. (2016) Nature, 534: 494-499; and Castro et al. (2019) JCI Insight, 4: e131712). Briefly, 13-week-old C57BL / 6J mice were fasted overnight with access to 5% glucose solution. After the fasting period, isofluorane- anaesthetised mice were administered an intracolonic enema of 0.1 mL dinitrobenzene sulfonic acid (DNBS) (6.5 mg in 30% ethanol) via a polyethylene catheter inserted 3 cm past the anus. Mice were then individually housed with unlimited access to soaked food and 5% glucose solution and observed daily for changes in body weight, physical appearance, and behaviour. Histological examination of mucosal architecture, cellular infiltrate, crypt abscesses, and goblet cell depletion confirmed that DNBS induced significant damage by day 3 post-treatment, with mucosal architecture largely recovered by day 7, and fully recovered by 28 days post-treatment. At 28 days post-DNBS treatment, these mice display sprouting of afferent central terminals in the dorsal horn, they have prominent hyperalgesia and allodynia to colorectal distension, and high-threshold nociceptors from these mice display significant mechanical hypersensitivity and lower mechanical activation thresholds. Thus, these mice are termed ‘CVH mice’.In vivo assessment of pain-related behaviour

[0360] The SAR study described in Example 2 identified several compounds exhibiting greater selectivity of inhibitory activity for NaV1.1 and NaV1.7 over NaV1.6. The greatest selectivity was seen in M6-NH2 (SEQ ID NO: 46) which displayed 83-fold selectivity for NaV1.1 over NaV1.6 and 19-fold selectivity for NaV1.7 over NaV1.6. Given the promising inhibitory results of this compound in vitro, the activity of the compound was confirmed in vivo in a mouse model of CVH.

[0361] Abdominal electromyography (EMG) was used to monitor the visceromotor response (VMR) to colorectal distension (CRD) in fully awake animals. For male C57BL / 6J mice the bare endings of two Teflon-coated stainless-steel wires (Advent Research Materials Ltd, Oxford, UK) were sutured into the right abdominal muscle and tunnelled subcutaneously (s.c.) to be exteriorised at the base of the neck for future access. At the end of the surgery, mice received prophylactic antibiotics (Baytril; 5 mg / kg s.c.) and analgesic (buprenorphine; 0.4 mg / 10 kg s.c.), then they were housed individually and allowed to recover for at least three days before assessment of VMR. On the day of VMR assessment, mice were briefly anesthetised using isoflurane before receiving a 100 µL enema of vehicle (saline). A lubricated balloon (2 cm length) was gently introduced through the anus and inserted into the colorectum up to 0.25 cm past the anal verge. The balloon catheter was secured to the base of the tail and connected to a barostat (Isobar 3, G&J Electronics, Willowdale, Canada) for graded and pressure-controlled balloon distension. Mice were allowed to recover from anaesthesia in a restrainer with dorsal access prior to initiation of the distension sequence. Distensions were applied at 20-40-50-60-70-80 mmHg (20 s duration each) at 2 min intervals so that the last distension was performed ~20 min after intracolonic treatment with vehicle. Following the final distension, colonic compliance was assessed by applying graded volumes (40–200 µL, 5 s duration each) to the balloon in the colorectum of fully awake mice while recording the corresponding colorectal pressure as described previously. Approximately 3.5 hours later mice then received intra-colonic administration of M6-NH2 (SEQ ID NO: 46) (100 nM or 1000 nM), allowing post-vehicle and post-M6-NH2 VMRs to CRD to be compared within the same animal. For the VMR recordings, the EMG electrodes were relayed to a data acquisition system. The signal was recorded (NL100AK headstage), amplified (NL104), filtered (NL 125 / 126, Neurolog, Digitimer Ltd, bandpass 50–5000 Hz), and digitised (CED 1401, Cambridge Electronic Design (CED), Cambridge, UK). The analogue EMG signal was rectified and integrated. To quantify the magnitude of the VMR at each distension pressure, the area under the curve (AUC) during the distension (20 s) was corrected for baseline activity (AUC pre-distension, 20 s). The total AUC, the summation of data points across all distension pressures, were also calculated for each animal.Statistics

[0362] VMR to CRD data are presented as mean ± SEM, where N represents the number of animals. Distension response data were analysed with a Two-way Repeated measures ANOVA, whilst total area under the curve (AUC) data were analysed with paired t-tests. Data were analysed with Prism 9 (GraphPad Software, San Diego, CA, USA) software with significance considered at *P<0.05, **P<0.01, ***P<0.001. Results

[0363] Using the in vivo visceromotor response (VMR) to colorectal distension (CRD) as an indicator of abdominal pain, intra-colonic administration of 1000 nM M6-NH2 yielded a significant reduction in the VMR to CRD in CVH mice (Figure 4), indicative of an analgesic action of M6-NH2. At a lower dose of 100 nM, M6-NH2 did not reduce the VMR to CRD in CVH mice (Figure 5), indicative of a dose-dependent analgesic effect. Notably, colonic compliance (or the elasticity of the colon) was not changed by either 100 nM or 1000 nM of M6-NH2 (Figure 6), suggesting that the analgesic action of M6-NH2 is mediated at the level of the afferent endings and is not due to a change in colonic muscle function. EXAMPLE 4 – EX VIVO ACTIVITY IN A PRECLINICAL COLONIC HYPERSENSITIVITY MODEL Materials and Methods Animals

[0364] All experiments were performed in accordance with the guidelines of the Animal Ethics Committees of the South Australian Health and Medical Research Institute (SAHMRI) and Flinders University. These experiments conformed to the relevant regulatory standards and the ARRIVE guidelines. Male C57BL / 6 mice at 10–13 weeks of age were used in all experiments. Mice were acquired from an in-house C57BL / 6J breeding program (JAX strain #000664; originally purchased from The Jackson Laboratory (breeding barn MP14; Bar Harbor, ME; USA)) within SAHMRI's specific and opportunistic pathogen- free animal care facility. Mice were group-housed (maximum five mice per cage) on individual ventilated cages (IVC), which were filled with coarse chip dust-free aspen bedding (PURA®; Catalogue no. ASPJMAEB-CA, PuraBed, Niederglatt, Switzerland). These cages were stored on IVC racks in specific housing rooms within a temperature-controlled environment of 22°C and a 12 h light / 12 h dark cycle. Mice had free access to LabDiet^JL Rat and Mouse / Auto6F chow (Catalogue no. 5K52, LabDiet, St Louis, MO, USA) and autoclaved reverse osmosis purified water. Mouse Model of Chronic Visceral Hypersensitivity (CVH)

[0365] Colitis was induced by administration of dinitrobenzene sulfonic acid (DNBS) as described previously (Osteen et al. (2016) Nature, 534: 494-499; and Castro et al. (2019) JCI Insight, 4: e131712). Briefly, 13-week-old C57BL / 6J mice were fastedovernight with access to 5% glucose solution. After the fasting period, isofluorane- anaesthetised mice were administered an intracolonic enema of 0.1 mL DNBS (6.5 mg in 30% ethanol) via a polyethylene catheter inserted 3 cm past the anus. Mice were then individually housed with unlimited access to soaked food and 5% glucose solution and observed daily for changes in body weight, physical appearance, and behaviour. Histological examination of mucosal architecture, cellular infiltrate, crypt abscesses, and goblet cell depletion confirmed that DNBS induced significant damage by day 3 post- treatment, with mucosal architecture largely recovered by day 7, and fully recovered by 28 days post-treatment. At 28 days post-DNBS treatment, these mice display sprouting of afferent central terminals in the dorsal horn, they have prominent hyperalgesia and allodynia to colorectal distension, and high-threshold nociceptors from these mice display significant mechanical hypersensitivity and lower mechanical activation thresholds. Thus, these mice are termed ‘CVH mice’. Colon-Pelvic Nerve Preparation and Intact Colon for Whole Nerve Recordings

[0366] To determine the effects of intraluminal M6-NH2 (100 nM or 1000 nM; prepared in accordance with Example 2) on distension sensitive afferents from male C57BL / 6J mice, colonic afferent recording preparations were utilised. The colon and rectum with attached splanchnic and pelvic nerves were removed, and recordings from distension sensitive afferents were performed as previously described (Bayrer et al. (2023) Nature, 616 (7955): 137-142). Briefly, the colon and rectum were removed and pinned flat, mucosal side up, in a specialised organ bath. The colonic compartment was superfused with a modified Krebs solution (in mM: 117.9 NaCl, 4.7 KCl, 25 NaHCO3, 1.3 NaH2PO4, 1.2 MgSO4 (H2O)7, 2.5 CaCl2, 11.1 D-glucose), bubbled with carbogen (95% O2, 5% CO2) at a temperature of 34°C. All preparations contained the L-type calcium channel antagonist nifedipine (1 μM) to suppress smooth muscle activity and the prostaglandin synthesis inhibitor indomethacin (3 μM) to suppress potential inhibitory actions of endogenous prostaglandins. The preparation was kept intact, and the colon ligated at either end to allow for fluid distension (100 μL / min, 0-80 mmHg). Distension was performed with vehicle or M6-NH2 (100 nM or 1000 nM) applied intraluminally. Whole splanchnic and pelvic nerve recordings were made using a sealed glass pipette containing a microelectrode (World Precision Instruments (WPI), Sarasota, USA) attached to a Neurolog headstage (NL100AK; Digitimer Ltd, Hertfordshire, UK). Nerve activity was amplified (NL104), filtered (NL 125 / 126, bandpass 50–5,000 Hz, Neurolog; Digitimer Ltd, Hertfordshire, UK), and digitised (CED 1401; Cambridge Electronic Design, Ltd (CED), Cambridge, UK) to a PC for offline analysis using Spike2 software (CED, Cambridge, UK). The number of action potentials crossing a pre-set threshold at twice the background electrical noise was determined per second to quantify the afferent response. Recordings were stored on a PC for off-line analysis.Statistics

[0367] Afferent recording data are presented as mean ± SEM, where N represents the number of animals. Data were compared using paired t-tests. Data were analysed with Prism 9 (GraphPad Software, San Diego, CA, USA) software with significance considered at *P<0.05, **P<0.01, ***P<0.001. As vehicle and M6-NH2 data were generated from the same preparation, data were also analysed and compared as the percentage of baseline response, or the percentage change from baseline. Results

[0368] Using an ex vivo colonic afferent recording preparation it was shown that a lower concentration of M6-NH2 at 100 nM did not significantly alter splanchnic or pelvic colonic afferents to distension (Figures 7 and 8). However, intra-luminal administration of a higher concentration (1000 nM) of M6-NH2 significantly inhibited both splanchnic and pelvic colonic afferents to distension in CVH mice (Figures 7 and 8). These findings confirm that the in vivo analgesic action of M6-NH2 is mediated via inhibition of colonic afferents. The ex vivo findings also demonstrate that the actions of M6-NH2 are dose dependent. EXAMPLE 5 – EX VIVO COLONIC MOTILITY STUDIES Materials and Methods Animals

[0369] All experiments were performed in accordance with the guidelines of the Animal Ethics Committees of the South Australian Health and Medical Research Institute (SAHMRI) and Flinders University. Male mice at 13-15 weeks of age were acquired from an in-house C57BL / 6J breeding program within SAHMRI's specific and opportunistic pathogen-free animal care facility. Mice were group-housed (maximum 5 mice per cage at any given time) within individually ventilated cages (IVC; GM500 model for mice, Tecniplast), which were filled with chip coarse dust-free aspen bedding (PuraChips Aspen coarse 63L; Catalogue no. ASPJMAEB-CA, Able Scientific, Australia). These cages were stored on IVC racks in specific housing rooms within a temperature-controlled environment of 22 ± 1°C and a 12 h light / 12 h dark cycle (6:30am-7am [dawn], 7am-7pm [full day light], 7pm-7:30pm [dusk], 7:30pm-6:30am [full night-time]). Mice had free access to autoclaved reverse osmosis purified water and standard laboratory mouse diet (irradiated rat and mouse cubes, 14 MJ / kg, 20% protein, 4.8% total fat, 4.8% crude fibre, 59.9% total carbohydrate, Specialty Feeds, Australia). For ex vivo studies, mice were humanely killed by CO2 overdose and euthanasia was confirmed by assessing the glazing of eyes (opaque and dry), absence of heartbeat, respiration, and corneal reflex before removing the heart via a bilateral clamshell thoracotomy.Test substance

[0370] M6-NH2 (prepared in accordance with Example 2) was diluted in milliQ water and a solution was obtained at a final stock concentration of 100 µM. Aliquots were made from stock solution and kept at -20°C until use. Krebs solution (composition in mmol / L: 118.4: NaCl; 24.9: NaHCO3; 1.9: CaCl2; 1.2: MgSO4; 4.7: KCl; 1.2: KH2PO4; 11.7 glucose) was used as the vehicle. Ex vivo mouse motility assay

[0371] An ex vivo mouse motility assay was performed to screen experimental compounds for effects on colonic motility, which provides an indication of the potential of the drug to induce diarrhoea or constipation. On the day of experimentation, mice were humanely killed, and their abdominal cavity was then opened and bathed in Krebs solution. The entire colon (from the caecum to the anus) was removed and placed into a bath of gassed Krebs solution. Using a syringe, the lumen was cleared of any contents by gentle flushing with Krebs solution. An adapted standard organ bath was used. A 5 cm to 6 cm segment of the colon was placed into the organ bath which was continuously perfused with warm gassed Krebs solution (33-36°C). The colon was tied on both ends with suture silk to prevent leakage of intracolonic fluid. The oral and aboral ends of the colon segment were attached to an input and output port of the organ bath respectively. The input port was connected to an infusion pump that continually pumped Krebs solution at a rate of 100 μL / min. The output port was attached to a pressure transducer (DTXPlus™, Bectin Dickinson, Oxford, UK) and outflow perfusion pump. Motor activity was initiated by an infusion of Krebs into the lumen of the colon via the infusion pump until an intraluminal pressure of approximately 7-10 mmHg was reached. At this point, the outflow perfusion pump (set at the same rate (100 µL / min)) was turned on and a stable intracolonic volume and pressure was obtained. Under these conditions, regular aborally propagating waves of contraction of consistent amplitude and frequency develop spontaneously and persist over time and can be recorded as changes in intraluminal pressure. The pressure transducer connected to the output port was also connected to a data acquisition system that converts changes in intraluminal pressure into an electrical signal. Motility experimental protocol

[0372] Propagating waves as spikes in intraluminal pressure were recorded until they became rhythmical over a calibration period (1 hour) with consistent amplitude and frequency. After this period, 30 minutes of baseline with vehicle (Krebs solution) was recorded. The solution in the syringe connected to the input pump was then changed to 100 nM M6-NH2 (30 min), followed by 1000 nM M6-NH2 (30 minutes) and finally Lidocaine (1 mg / mL, 30 minutes). The electrical signal generated by the pressure transducer was digitized (CED 1401, Cambridge Electronic Design, Cambridge, UK) to a PC for off-lineanalysis using Spike2 version 5.16 (Cambridge Electronic Design, Cambridge, UK). Off-line analysis was done using Spike2 software and amplitude, frequency and AUC of pressure spikes was determined. All data were analysed using Prism 9 software (GraphPad Software, San Diego, CA, USA) using one-way ANOVA. Statistical significance was determined as p≤0.05. Data was expressed as mean + / - SEM. Statistics

[0373] Data are presented as mean ± SEM, where N represents the number of preparations and animals. All data were analysed using Prism 9 software (GraphPad Software, San Diego, CA, USA) using one-way ANOVA. Statistical significance was determined at *P<0.05, **P<0.01, ***P<0.001. Results

[0374] Using the ex vivo colonic motility preparation it was shown that intraluminally applied M6-NH2, at concentrations of 100nM and 1000nM, does not significantly alter colonic motility. This is determined by the Area Under the Curve (AUC) of the colonic contractions, the amplitude of contractions and the overall frequency of contractions (Figure 9). These findings confirm that M6-NH2 does not alter colonic motility and the in vivo analgesic effects are mediated by inhibition of colonic afferents and that these actions of M6-NH2 are dose dependent. EXAMPLE 6 – PEPTIDE GASTROINTESTINAL STABILITY Materials and Methods

[0375] Test peptides and wild-type Hs1a and derivatives thereof were synthesised in accordance with the method of Example 2.

[0376] Simulated intestinal fluid (SIF) was prepared as per United States Pharmacopeia specifications (Test Solutions, United States Pharmacopeia 35, NF 30, 2012). In short, SIF was prepared by dissolving KH2PO4 (68 mg) in 0.5 mL MilliQ followed by addition of 0.8 mL NaOH (0.2 M) and 100 mg of porcine pancreatin prior to dilution to 10 mL with MilliQ (pH 6.8). Peptide stocks [M5-NH2, M6-NH2, linaclotide, Hs1a WT (Hs1a- COOH), amidated Hs1a (Hs1a-CONH2), and reduced Hs1a (Hs1a – reduced)] were diluted in SIF (final peptide concentration 50 μM) and incubated at 37°C with gentle shaking. Aliquots were taken at 0 min, 5 min, 10 min, 15 min, 30 min, 1 h, 2 h, 4 h , 8 h, 24 h and 48 h for SIF. Aliquots were quenched with aqueous TFA (10%) for SIF. Aliquots were centrifuged with the supernatant analysed via analytical ultra-performance liquid chromatography (UPLC; Phenomenex Aeris XB-C18 column; 250 x 4.6 mm; particle size 3 μm; pore size 100 Å) using solvent A (MilliQ water with 0.05% trifluoroacetic acid) with a gradient of 20 - 40 % solvent B (90% acetonitrile, ~10% MilliQ, 0.043% TFA) over 20 min. Percentage of intact peptide was calculated via measuring the peak area and dividing it bythe peak area from the 0 h time point. Half-lives (t1 / 2) were calculated by fitting an exponential one-phase decay function using GraphPad Prism (v9.0) (GraphPad Software, San Diego, CA, USA). Results

[0377] For most peptides to become orally active therapeutics, they preferably have properties that permit them to both survive the harsh environment of the gastrointestinal tract and traverse the intestinal epithelium in order to reach the systemic circulation. However, Hs1a has the same advantage as drugs such as linaclotide whereby its therapeutic target is within the gastrointestinal system, thus the primary limiting factor for oral bioavailability is stability in the gastrointestinal tract. The stability of several lead candidates under simulated gastrointestinal tract conditions were therefore investigated (Figure 10). M5-NH2 (SEQ ID NO: 37) and M6-NH2 (SEQ ID NO: 46) were found to have half-lives of 687 and 511 min respectively, which are both substantially increased compared to wild-type Hs1a (62 min). With reference to the average transit time of 30 h throughout the gastrointestinal tract (in healthy individuals), the increased stability of M5- NH2 and M6-NH2 under simulated gastrointestinal tract conditions should improve the amount of intact peptide reaching the colon, potentially allowing for a lower dosage of the peptide(s) to achieve efficacy. EXAMPLE 7 – DESIGN AND ACTIVITY OF FURTHER HS1A ANALOGUES Materials and Methods

[0378] Test peptides were synthesised in accordance with the method of Example 2.

[0379] The activity of the Hs1a analogues was examined against NaV1.1, NaV1.7 and NaV1.6 using automated whole-cell patch-clamp electrophysiology as described in Example 2. IC50 values were obtained by fitting a Hill equation with variable slope to concentration–response curves via linear regression using Prism v.8 (GraphPad Software, San Diego, CA, USA). Results

[0380] Alanine variants of M6-NH2 (SEQ ID NO: 46) were designed and tested for inhibition of NaV1.1, NaV1.7 and NaV1.6. The sequences are presented in Table 8.

[0381] The activity of the Hs1a analogues is presented in Table 9. Data are presented as mean ± standard error of the mean (SEM) based on N independent experiments in Table 9, with the concentration-response curves provided in Figures 11-13. The Hs1a analogues were found to be potent inhibitors of Nav1.7 and Nav1.1, with decreased activity at Nav1.6.TABLE 8 SEQUENCES OF FURTHER HS1A ANALOGUES Peptide Sequence SEQ ID NOACTIVITY OFHS1A ANALOGUES ON HUMANNAVCHANNEL SUBTYPES USING AUTOMATED WHOLE- CELL PATCH-CLAMP ELECTROPHYSIOLOGY. THEIC50VALUES ARE EXPRESSED IN NM.hNaV1.7β1 hNaV1.1β1 hNaV1.6β1 Peptide IC50 N IC50 N IC50 NEXAMPLE 8 – NAV1.1 TO NAV1.9 EXPRESSION IN MOUSE AND HUMAN TISSUE Materials and Methods

[0382] All experiments involving mice were performed in accordance with the guidelines of the Animal Ethics Committees of the South Australian Health and Medical Research Institute (SAHMRI). Male mice at 13-15 weeks of age were acquired from an in- house C57BL / 6J breeding program within SAHMRI's specific and opportunistic pathogen- free animal care facility. Mice were group-housed (maximum 5 mice per cage at any given time) within individually ventilated cages (IVC; GM500 model for mice, Tecniplast), which were filled with chip coarse dust-free aspen bedding (PuraChips Aspen coarse 63L; Catalogue No. ASPJMAEB-CA, Able Scientific, Australia). These cages were stored on IVC racks in specific housing rooms within a temperature-controlled environment of 22 ± 1°C and a 12 h light / 12 h dark cycle (6:30am-7am [dawn], 7am-7pm [full day light], 7pm- 7:30pm [dusk], 7:30pm-6:30am [full night-time]). Mice had free access to autoclaved reverse osmosis purified water and standard laboratory mouse diet (irradiated rat and mouse cubes, 14 MJ / kg, 20% protein, 4.8% total fat, 4.8% crude fibre, 59.9% total carbohydrate, Specialty Feeds, Australia).

[0383] For single cell RT-PCR expression studies in mouse neurons, separate cohorts of mice underwent i) subserosal or ii) mucosal retrograde tracing from the colon using cholera toxin subunit B conjugated to AlexaFluor-555 (Catalogue No. CTB-555;Invitrogen, Victoria, Australia) injected at multiple sites within the distal colon. Animals were left to recover for 4 days in order to allow the fluorescent tracer to travel from the colon to the cell soma within the thoracolumbar (T10-L1, TL) or lumbosacral (L6-S1, LS) DRG. Mice were humanely killed by CO2 overdose and euthanasia was confirmed by assessing the glazing of eyes (opaque and dry), absence of heartbeat, respiration, and corneal reflex before removing the heart via a bilateral clamshell thoracotomy. TL and LS DRG were surgically removed and the DRGs were enzymatically and mechanically dissociated. DRG neurons were spot platted onto coverslips and single fluorescently traced neurons picked using a modified patch clamp glass electrode (airfilled wide-aperture borosilicate glass pipette fabricated in the P-97 Sutter Instruments pipette puller). Neurons were added to 10 µL of lysis buffer with DNase (Thermo Fisher Scientific, TaqMan Gene Expression Cells-to-CT Kit, Catalogue No. AM1728). Incubation with lysis buffer occurred for 5 to 10 minutes at room temperature, followed by addition of 1 µL DNase stop solution and incubation for a further 5 to 10 minutes at room temperature. Lysates were frozen on dry ice and stored at -80°C until cDNA synthesis was performed. Synthesis of cDNA was performed using the SuperScript VILO IV ezDNase (Thermo Fisher Scientific, Catalogue No.11766050) kit according to the manufacturer’s instructions. For each RT-PCR reaction, 10 µL of PCR Master mix, 0.5 µL of each TaqMan primer, 8 µL of water, and 1.6 µL cDNA from each sample was tested in singlet for each target. Tubb3 was used as a neuronal marker, and Gfap was used as a glial marker. RT controls, bath controls, and negative controls (water instead of cDNA) were routinely included in PCR reactions, and a positive control test was performed for each primer using cDNA synthesised from whole DRG RNA. Assays were run for 50 cycles on a 7500 Fast Real-Time PCR System (Applied Biosystems, Victoria, Australia) machine, using 7500 Fast software, v2.0.6. Genes were considered expressed if a complete amplification curve was obtained within 50 cycles. The following probes were used for determining NaV1.1-1.9 expression: NaV1.1 Scn1a Mm00450580_m1 NaV1.2 Scn2a1 Mm01270359_m1 NaV1.3 Scn3a Mm00658167_m1 NaV1.4 Scn4a Mm00500103_m1 NaV1.5 Scn5a Mm01342518_m1 NaV1.6 Scn8a Mm00488110_m1 NaV1.7 Scn9a Mm00450762_s1 NaV1.8 Scn10a Mm00501467_m1 NaV1.9 Scn11a Mm00449367_m1

[0384] For expression studies in i) whole TL or LS DRG or ii) colonic mucosal scrapings from healthy and CVH mice, tissue were collected immediately after euthanasia by CO2inhalation. For DRG, whole TL and LS DRG were surgically removed, snap frozen, and stored at -80°C before RNA extraction. Colonic mucosa were collected by removing the colon, opening it longitudinally and using a scalpel blade to scrap the mucosa from the colon, which was then snap frozen and stored at -80°C before RNA extraction. RNA was extracted using the PureLink RNA Micro kit (Invitrogen, Victoria, Australia, Catalogue No. 12183-016; DRG) or the PureLink RNA Mini kit (Invitrogen, Catalogue No. 12183018A; colonic mucosal tissue) followed by a DNAse treatment (Life Technologies, Catalogue No. 12185-010) according to the manufacturer’s instructions. Quantitative RT-PCR (QRT-PCR) was performed using Express qPCR Supermix (Applied Biosystems, Catalogue No. 11785200) with commercially available hydrolysis probes (TaqMan; Life Technologies, see above for details) and RNAse-free water (AMBION, Victoria, Australia, Catalogue No. AM9916). For each reaction, 10 µL of qPCR SuperMix, 1 µL of TaqMan primer, 2 µL RT enzyme mix, 2 µL of water, and 5 µL of RNA (diluted in RNAse-free H2O to approximately 100 ng / well) from each sample were tested in duplicate for each NaV channel subtype. Assays were run for 50 cycles on a 7500 Fast Real-Time PCR System (Applied Biosystems) machine, using 7500 Fast software, v2.0.6. Quantity of mRNA is expressed as delta Ct relative to the geometric mean of reference genes Hprt and Gapdh.

[0385] For expression studies in human tissues, thoracolumbar (TL) DRG (T9– L1) were acquired from Anabios who collected DRG (with appropriate ethics and consent) from four human adult organ donors during the removal of the vital organs for transplantation. The harvested DRG were immediately processed for downstream RNA studies. Intact DRG were kept for QRT-PCR mRNA expression studies from each spinal level (T9, T10, T11, T12, L1). Human colonic biopsies were collected with appropriate ethics and consent from 3 healthy subjects acquired from the Department of Gastroenterology, Royal Adelaide Hospital. NaV1.1-1.9 expression was detected as described above for mouse tissues, except for the use of human specific primers, as listed below (Thermo Fisher Scientific): NaV1.1 SCN1A Hs00374696_m1 NaV1.2 SCN2A Hs01109877_m1 NaV1.3 SCN3A Hs00366902_m1 NaV1.4 SCN4A Hs01109480_m1 NaV1.5 SCN5A Hs00165693_m1 NaV1.6 SCN8A Hs00274075_m1 NaV1.7 SCN9A Hs00161567_m1 NaV1.8 SCN10A Hs01045137_m1 NaV1.9 SCN11A Hs00204222_m1Tubb3 Hs00964962_g1 GFAP Hs00909233_m1 Results

[0386] Using sub-serosal retrograde tracing from the colon of healthy mice identified the main classes of colonic afferents that signal pain, apart from mucosal afferents (see below). Using downstream single cell RT-PCR from these individual colon- innervating TL DRG from healthy mice it was shown that abundant expression of alpha subunits of NaV channels occurred in these neurons. This included expression of both NaV1.1 (33% of neurons) and NaV1.7 (100% of neurons) (Figure 14). This indicates that the target of the peptides of the disclosure are expressed on sensory neurons innervating the colon. Furthermore, single cell RT-PCR from these neurons revealed that the beta subunits of NaV channels are expressed in TL and LS DRG neurons innervating the healthy mouse colon (Figure 15). Recent studies have shown that LS DRG afferents innervating the colonic mucosa connect with enterochromaffin cells in the epithelial lining and that this communication not only drives visceral pain, but also anxiety (Bayrer et al. (2023) Nature, 616 (7955): 137-142). Using retrograde tracing from the colonic mucosa allowed identification of mucosal afferents, but not the other colonic afferents identified with sub- serosal tracing (as outlined above). Using single cell RT-PCR of colonic mucosal afferent neurons identified a different profile of NaV expression compared with that described above for neurons identified by sub-serosal tracing. However, both NaV1.1 and NaV1.7 were expressed in these mucosa innervating colonic afferents, with higher proportional expression of NaV1.1 relative to colonic neurons identified with sub-serosal tracing (Figure 16). These neurons also expressed the beta NaV subunits (Figure 16).

[0387] Using whole TL (Figure 17A) and LS (Figure 17B) DRG from healthy and CVH mice allowed comparison of NaV expression in diseases states relevant to irritable bowel syndrome and inflammatory bowel disease. QRT-PCR revealed an increase in the amount of NaV1.1 and NaV1.7 expressed in TL and LS DRG from CVH states, indicating that the targets of the peptides of the disclosure are up-regulated in disease states relevant to irritable bowel syndrome and inflammatory bowel disease.

[0388] Using sub-serosal retrograde tracing from healthy and CVH mice allowed comparison of NaV expression within individual colonic DRG neurons in diseases states relevant to irritable bowel syndrome and inflammatory bowel disease. Single cell RT-PCR from TL DRG neurons innervating the colon demonstrated an increase in the number of neurons expressing NaV1.1 (33% healthy vs. 47% CVH) (Figure 18), indicating that the key target of the peptides of the disclosure is up-regulated in disease states relevant to irritable bowel syndrome and inflammatory bowel disease. This is important as it haspreviously been shown that NaV1.1 has an increased functional role in the CVH state (Osteen et al. (2023) Nature, 23 (7608): 494-499).

[0389] Using QRT-PCR of colonic mucosal tissue from healthy and CVH mice revealed a vastly different NaV expression profile compared to the profiles observed in i) whole DRG, ii) colon innervating DRG neurons identified by sub-serosal tracing and iii) colon innervating DRG neurons identified with mucosal tracing. In healthy and CVH mouse colonic mucosa, the most abundant NaV expressed was NaV1.3, with NaV1.1 below the limit of detection and very small amounts of NaV1.7 (Figure 19). This indicates that the main targets of the peptides of the disclosure are not expressed in the colonic mucosa, but are expressed in colon-innervating DRG neurons (as outlined above).

[0390] Using TL DRG from four human organ donors allowed the comparative expression of NaV1.1-1.9 to be determined at individual DRG (T9, T10, T11, T12, L1) levels that are relevant to the sensory afferent innervating of the colon. Using QRT-PCR showed high expression of NaV1.1 and NaV1.7 in human DRG, and that this expression profile was broadly consistent across different levels (T9-L1, Figure 20). These findings indicate the main targets of the peptides of the disclosure are expressed by human DRG neurons, with the expression profiles of NaV1.1 and NaV1.7 comparing well with mouse expression studies (as outlined above). Using colonic biopsies from three human healthy subjects, QRT-PCR demonstrated that like the results found in the mouse, NaV1.1 was expressed below the level of detection, with relatively small amounts of NaV1.7 expression (Figure 21), particularly when compared with NaV1.7 expression in whole DRG (compare Figures 20 and 21). These findings again indicate the main targets of the peptides of the disclosure are not expressed in the colonic mucosa, rather they are expressed by DRG neurons.

[0391] Overall, the data show that Nav1.1 and NaV1.7 (the key targets of the peptides of the disclosure) are located on sensory DRG neurons innervating the colonic mucosa and colon wall, indicating that the peptides of the disclosure block the major nociceptive pathways from the colon to the brain. The data further show that Nav1.1 is up- regulated in these neurons in the disease state.

[0392] The disclosure of every patent, patent application, and publication cited herein is hereby incorporated herein by reference in its entirety.

[0393] The citation of any reference herein should not be construed as an admission that such reference is available as “Prior Art” to the instant application.

[0394] Throughout the specification the aim has been to describe the preferred embodiments of the invention without limiting the invention to any one embodiment or specific collection of features. Those of skill in the art will therefore appreciate that, in lightof the instant disclosure, various modifications and changes can be made in the particular embodiments exemplified without departing from the scope of the present invention. All such modifications and changes are intended to be included within the scope of the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A molecule comprising an amino acid sequence represented by Formula I: CLX1X2X3X4ACNPX5NDKCCANX29VCSX6X7HX8X9C (I) wherein: X1 is a small amino acid residue or an acidic amino acid residue; X2 is a hydrophobic amino acid residue or a small amino acid residue; X3 is a hydrophobic amino acid residue; X4 is a small amino acid residue; X5 is a basic amino acid residue; X6 is a small amino acid residue or a basic amino acid residue; X7 is a basic amino acid residue; X8 is a basic amino acid residue; X9 is any amino acid residue; and X29 is any amino acid residue, wherein the molecule is other than a molecule comprising an amino acid sequence of SEQ ID NO: 1: NDCLGFWSACNPKNDKCCANLVCSSKHKWCKGKL [SEQ ID NO: 1].

2. The molecule according to claim 1, wherein: X1 is selected from A, S, G, T, D, E and modified forms thereof; X2 is selected from M, I, L, V, F, Y, W, Nle, 4-benzoyl-L-phenylalanine (Bpa), 4,4’- biphenylalanine (Bip), A, S, G, T and modified forms thereof; X3 is selected from M, I, L, V, F, Y, W, Nle and modified forms thereof; X4 is selected from A, S, G, T, homoserine (hS) and modified forms thereof; X5 is selected from R, K and modified forms thereof; X6is selected from A, S, G, T, R, K and modified forms thereof; X7 is selected from R, K and modified forms thereof; X8 is selected from R, K, homoarginine (hR), diaminobutyric acid (Dab) and modified forms thereof; X9 is selected from M, I, L, V, F, Y, W, Nle, Bpa, Bip, A, G, S, T and modified forms thereof; andX29 is selected from M, I, L, V, F, Y, W, Nle, A, G, S, T and modified forms thereof.

3. The molecule according to claim 1 or claim 2, wherein X1 is selected from G and E.

4. The molecule according to any one of claims 1-3, wherein X2 is selected from F, Bip, A and Bpa.

5. The molecule according to claim 4, wherein X2is Bip.

6. The molecule according to any one of claims 1-5, wherein X3 is W.

7. The molecule according to any one of claims 1-6, wherein X4 is selected from S and hS.

8. The molecule according to any one of claims 1-7, wherein X5 is selected from K and R.

9. The molecule according to any one of claims 1-8, wherein X6 is selected from K and S.

10. The molecule according to any one of claims 1-9, wherein X7 is selected from K and R.

11. The molecule according to any one of claims 1-10, wherein X8 is selected from K, R, Dab and hR.

12. The molecule according to any one of claims 1-11, wherein X9 is selected from W, Bpa, A and Bip.

13. The molecule according to claim 12, wherein X9is A.

14. The molecule according to any one of claims 1-13, wherein X29 is selected from L and A.

15. The molecule according to any one of claims 1-14, wherein the molecule is represented by Formula II: X10X11X12CLX1X2X3X4ACNPX5NDKCCANX29VCSX6X7HX8X9CX13X14X15X16 (II) wherein: X1 to X9 and X29 are as defined in any one of claims 1-14; X10 is absent or is a small amino acid residue; X11 is an amide-containing amino acid residue; X12 is an acidic amino acid residue; X13 is a basic amino acid residue; X14 is a small amino acid residue; X15 is a basic amino acid residue; and X16 is a hydrophobic amino acid residue.

16. The molecule according to claim 15, wherein: X10 is absent or is selected from A, S, G, T and modified forms thereof; X11 is selected from N, Q and modified forms thereof; X12 is selected from D, E and modified forms thereof; X13 is selected from R, K, hR and modified forms thereof; X14 is selected from A, S, G, T and modified forms thereof; X15 is selected from R, K, Ornithine (Orn) and modified forms thereof; and X16 is selected from M, I, L, V, F, Y, W, Nle and modified forms thereof.

17. The molecule according to any one of claims 1-16, wherein the molecule comprises, consists or consists essentially of an amino acid sequence represented by any one of SEQ ID NOs: 2-33 and 51-54: GNDCLGFWSACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 2]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 3]; GNDCLGX19WSACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 4]; GNDCLGFWX20ACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 5]; GNDCLGFWSACNPRNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 6]; GNDCLGFWSACNPKNDKCCANLVCSKKHKWCKAX17L [SEQ ID NO: 7]; GNDCLGFWSACNPKNDKCCANLVCSSKHX21WCKAX17L [SEQ ID NO: 8]; GNDCLGX19WSACNPKNDKCCANLVCSSKHX21WCKAX17L [SEQ ID NO: 9]; GNDCLGX19WX20ACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 10]; GNDCLGX19WSACNPRNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 11]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX18CKGX17L [SEQ ID NO: 12]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX18CKAKL [SEQ ID NO: 13]; GNDCLEFWSACNPKNDKCCANLVCSSKHKX18CX22GKL [SEQ ID NO: 14]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX18CX22GKL [SEQ ID NO: 15]; GNDCLEFWSACNPKNDKCCANLVCSSKHKWCX22GKL [SEQ ID NO: 16]; GNDCLEFWSACNPKNDKCCANLVCSSKHKX18CKGKL [SEQ ID NO: 17]; GNDCLGX18WSACNPKNDKCCANLVCSSKHKWCKAX17L [SEQ ID NO: 18]; GNDCLGFWSACNPKNDKCCANLVCSSKHKWCRAX17L [SEQ ID NO: 19];GNDCLGFWSACNPKNDKCCANLVCSSRHKWCKAX17L [SEQ ID NO: 20]; GNDCLGFWSACNPKNDKCCANLVCSSKHRWCKAX17L [SEQ ID NO: 21]; GNDCLGFWSACNPKNDKCCANLVCSSKHX22WCKAX17L [SEQ ID NO: 22]; GNDCLGFWSACNPKNDKCCANLVCSSKHKX19CKAX17L [SEQ ID NO: 23]; GNDCLGX18WSACNPKNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 24]; GNDCLGX19WSACNPKNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 25]; GNDCLGFWX20ACNPKNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 26]; GNDCLGFWSACNPRNDKCCANLVCSSKHKX18CKAX17L [SEQ ID NO: 27]; GNDCLGFWSACNPKNDKCCANLVCSKKHKX18CKAX17L [SEQ ID NO: 28]; GNDCLGFWSACNPKNDKCCANLVCSSRHKX18CKAX17L [SEQ ID NO: 29]; GNDCLGFWSACNPKNDKCCANLVCSSKHRX18CKAX17L [SEQ ID NO: 30]; GNDCLGFWSACNPKNDKCCANLVCSSKHX22X18CKAX17L [SEQ ID NO: 31]; GNDCLGFWSACNPKNDKCCANLVCSSKHX21X18CKAX17L [SEQ ID NO: 32]; GNDCLGX19WSACNPKNDKCCANLVCSKKHKWCKAX17L [SEQ ID NO: 33]; GNDCLGAWSACNPKNDKCCANLVCSSKHX21WCKAX17L [SEQ ID NO: 51]; GNDCLGX19WSACNPKNDKCCANAVCSSKHX21WCKAX17L [SEQ ID NO: 52]; GNDCLGX19WSACNPKNDKCCANLVCSSKHX21ACKAX17L [SEQ ID NO: 53]; and GNDCLGX19WSACNPKNDKCCANAVCSSKHX21ACKAX17L [SEQ ID NO: 54], wherein: X17 is Orn; X18 is Bpa; X19 is Bip; X20 is hS; X21 is Dab; and X22 is hR.

18. The molecule according to claim 17, wherein the molecule comprises, consists or consists essentially of an amino acid sequence represented by any one of SEQ ID NOs: 2-11, 52 and 53.

19. The molecule according to any one of claims 1-18, wherein the six cysteine residues in the molecule are bonded in pairs to form three disulfide bonds, whereinthe disulfide bonds are formed between the side chains of Cys 1 and Cys 16, Cys 8 and Cys 21, and Cys 15 and Cys 28 (numbered in accordance with the amino acid sequence of Formula I).

20. The molecule according to any one of claims 1-19, wherein the molecule comprises a C-terminal amide.

21. A composition comprising, consisting or consisting essentially of a molecule according to any one of claims 1-20 and a pharmaceutically acceptable excipient.

22. A molecule according to any one of claims 1-20 for use in therapy.

23. A method of treating or at least partially inhibiting the development of a condition in which inhibiting Nav1.1 and / or Nav1.7 activity is associated with effective treatment or inhibition of the condition, comprising administering an effective amount of the molecule according to any one of claims 1-20.

24. The method according to claim 23, wherein the condition is pain.

25. The method according to claim 23, wherein the condition is anxiety.

26. A method of treating or at least partially inhibiting the development of pain in a subject, comprising administering an effective amount of the molecule according to any one of claims 1-20 to the subject.

27. The method according to claim 26, wherein the pain is chronic pain.

28. The method according to claim 26 or claim 27, wherein the pain is selected from the group consisting of inflammatory pain, mechanical pain, visceral pain, abdominal pain and nociceptive pain.

29. The method according to claim 28, wherein the pain is visceral pain.

30. The method according to claim 28, wherein the pain is abdominal pain, endometrial pain or bladder pain.

31. The method according to any one of claims 28-30, wherein the pain is associated with irritable bowel syndrome, inflammatory bowel disease, gastrointestinal inflammation, a gastric motility disorder, endometriosis or a urinary tract infection.

32. A method of antagonising Nav1.1 and / or Nav1.7, comprising contacting Nav1.1 and / or Nav1.7 with a molecule according to any one of claims 1-20.

33. Use of a molecule according to any one of claims 1-20 as an analgesic.

34. An abdominal pain analgesic comprising a molecule having a voltage- gated sodium channel inhibitory profile characterised by an IC50 of 100 nM or less for Nav1.1 and Nav1.7, and an IC50 for Nav1.1 at least two-fold lower than the IC50 for Nav1.

6.

35. The abdominal pain analgesic according to claim 34, wherein the molecule comprises, consists or consists essentially of an amino acid sequence that isdistinguished from the amino acid sequence of SEQ ID NO: 1 by at least one amino acid modification: NDCLGFWSACNPKNDKCCANLVCSSKHKWCKGKL [SEQ ID NO: 1].

Images