Pharmaceutical composition

Abstract

Pharmaceutical composition for pain relief for topical use and action, comprising as active ingredient, one or more peptide(s) of the ω-conotoxin family, of natural or synthetic origin, or one of their variant(s), natural or synthetic, functionally active, for use in a method of treating acute or chronic pain, of a nociceptive, neuropathic or nociplastic nature, such as intense chronic inflammatory and neuropathic pain, characterized in that it is administered locally, by cutaneous route, near and at the level of the free cutaneous endings of the nociceptors innervating the skin. Figure 1C

Description

Title of the invention: Pharmaceutical composition

[0001] The present invention falls within the field of pharmaceutical compositions, comprising as active ingredient one or more peptide(s) of the co-conotoxin family, for use in the treatment of acute or chronic pain, of a nociceptive, neuropathic or nociplastic nature, such as for example intense chronic inflammatory and neuropathic pain.

[0002] The invention particularly relates to a pharmaceutical composition comprising a co-conotoxin, for example of the MVIIA type, for use in a method of treating severe chronic inflammatory and neuropathic pain, which is administered locally, via the skin, near the terminals of the sensory fibers of the cutaneous nociceptors innervating the skin.

[0003] Co-conotoxins are toxins produced either naturally by marine molluscs of the genus Conus, or synthetically by any peptide synthesis methods known to those skilled in the art.

[0004] Naturally occurring co-conotoxins identified in marine cones such as Conus cactus, Conus magus and Conus geographus, Conus striatus, Conus tulipa, Conus consors, Conus textile, Conus radiatus and Conus fulmen are generally peptides with between 10 and 30 amino acid residues, which may have post-translational modifications such as an amidated C-terminus and up to six cysteine ​​residues arranged to form a three-dimensional four-loop structure.

[0005] Co-conotoxins act on so-called "voltage-dependent calcium channels" or "Cavs", particularly including N-type voltage-dependent calcium channels present in abundance in the dorsal horn region of the spinal cord.

[0006] Cavs help transmit the nociceptive message from the peripheral nervous system to the central nervous system. Cavs are one of the main pathways for calcium entry into the nerve cell in response to an action potential, which involves the release of neurotransmitters into the synapse, and consequently, the transmission of the pain signal. Cavs are therefore key players in the transmission of the nociceptive signal (Hoppanova, L et al, (2022) Pflugers Arch - Eur J Physiol 474, 421-434, DOI 10.1007 / s00424-022-02666-y) and a pharmacological target of choice for analgesics.

[0007] Consequently, co-conotoxins, targeting N-type Cavs, involved in the synaptic transmission of the nociceptive signal, are of great therapeutic interest, particularly as an alternative to opiates in the treatment of pain.

[0008] However, peptides of the co-conotoxin family, impacting Cavs, are peptides potentially sensitive to proteases and peptidases. This sensitivity limits their bioavailability in the body and complicates their administration in order to act on a defined therapeutic target.

[0009] In order to increase their stability in vivo, in particular to avoid alteration by proteases, or to facilitate their distribution, it has been envisaged to synthesize modified co-conotoxins, such as for example cyclic co-conotoxins, comprising modified amino acids or coupled with protective groups. Nevertheless, this synthesis of modified peptides is complex because a modification of the three-dimensional structure of the peptide or its physicochemical characteristics (charge, polarity, molecular weights) does not guarantee the conservation of its biological activity. In particular, modifying the biochemical structure of a peptide of the co-conotoxin family can complicate its administration, impact its selectivity and specificity of action on Cavs or even increase its toxicity with respect to the organism.

[0010] Still with the aim of using co-conotoxins in therapy, as an alternative to opiates which can generate addiction, it has been considered to administer co-conotoxins directly and as close as possible to the therapeutic target, in particular by parenteral routes.

[0011] For example, it is known to treat severe chronic pain with ziconotide, which is a synthetic equivalent of co-conotoxin MVIIA, isolated from Conus magus.

[0012] Ziconotide is a peptide that inhibits N-type Cavs present on neurons. Ziconotide prevents calcium from penetrating into nerve endings, which then no longer release their mediators.

[0013] Ziconotide is marketed under the name PRIALT® as a centrally acting analgesic drug. When delivered to the spinal cord and arriving in the dorsal horns, ziconotide blocks presynaptic Cav2.2 and prevents the entry of calcium in response to action potentials traveling through nociceptive afferent fibers, and the release of neurotransmitters and neuropeptides into the synapse. There is therefore no stimulation of the postsynaptic neurons, which prevents the transmission of the pain signal to the brain. Under the action of ziconotide, the transmission of the pain message at the synaptic level in the dorsal horns of the spinal cord is reduced.

[0014] Inactivated by enzymatic hydrolysis via peptidases, and unable to cross the blood-brain barrier, ziconotide has been granted marketing authorization to treat severe, refractory chronic pain resistant to opioids. However, ziconotide is authorized only for administration as an intraspinal solution, i.e. administration by infusion via a catheter of a ziconotide solution directly between the spinal cord and the dura- mother, which allows rapid mixing and diffusion into the cerebrospinal fluid. Intraspinal administration of ziconotide generates an analgesic action.

[0015] By intraspinal route, ziconotide acts permanently, as close as possible to the Cav2.2 target at the level of the posterior horn of the spinal cord, where it will then inhibit the release of mediators such as substance P or glutamate, thus reducing pain.

[0016] Nevertheless, taking into account its galenic form and its intraspinal administration method, ziconotide PRIALT® remains of limited prescription, of last resort for the treatment of intense chronic pain and reserved for patients for whom even intrathecal morphine does not provide relief.

[0017] Indeed, ziconotide in solution, administered intraspinally, presents several risks of undesirable effects.

[0018] Following its administration by intraspinal route, ziconotide can cause central side effects, such as neuropsychiatric disorders or a confusional state but also hallucinations, memory loss, anxiety attacks, anxiety, balance disorders, dysarthria, or even nausea, vomiting, abdominal pain and myalgia, and physiological effects in certain patients such as an asymptomatic elevation of Creatine Phospho Kinase.

[0019] In addition to these central, cognitive and physiological disorders, intraspinal administration is an invasive route of administration for the organism to be treated. Indeed, the intraspinal route presents in itself an infectious risk, in particular through the placement of the catheter itself, or associated with the implantable or external pump.

[0020] Furthermore, in addition to the risk of infection, intraspinal administration requires the intervention of a healthcare professional and does not allow the patient to manage their pain by controlling the dosage of the ziconotide solution.

[0021] Consequently, in order to avoid the use of opiates and with the aim of treating pain with peptides of the co-conotoxin genus, while limiting the side effects and the risks of infection, the present invention aims to overcome the drawbacks of the state of the art by proposing a pain-relieving pharmaceutical composition for topical use and action, comprising as active ingredient, one or more peptide(s) of the co-conotoxin family, of natural or synthetic origin, or one of their variant(s), natural or synthetic, functionally active, for use in a method of treating acute or chronic pain, of a nociceptive, neuropathic or nociplastic nature, such as intense chronic inflammatory and neuropathic pain.Specifically to the invention, said composition is administered locally, via the skin, near and at the level of the free cutaneous endings of the nociceptors innervating the skin.

[0022] Preferably, the composition of the invention comprises a single type of peptide from the co-conotoxin family, preferably of synthetic origin.

[0023] According to the invention, pain is classified according to its duration over time.

[0024] “Acute pain” means a warning symptom, transient in time, which corresponds to an unpleasant sensory physiological response linked to the stimulation of peripheral nociceptors by mechanical, thermal, or chemical stimuli.

[0025] In contrast, "chronic pain" is pain that lasts over time, at least beyond 3 months, and which persists even if the cause of the pain has disappeared. In the case of chronic pain, the sensation of pain is no longer a warning signal but becomes a disease in its own right with physical, moral and social consequences.

[0026] In addition, pain is also classified according to its nature.

[0027] In the present invention, a distinction is made between “nociceptive pain”, “neuropathic pain” and “nociplastic pain”.

[0028] "Nociceptive pain" is that linked to the stimulation of nociceptors by a chemical (e.g., inflammation), thermal (e.g., heat source generating, for example, a burn) or mechanical (e.g., crushing / cut) stimulus. Nociceptive pain is a response to an attack on the body or its dysfunction in response to trauma, injury, or infection damaging tissues or organs and creating an abnormality. Nociceptive pain generally disappears quickly after the cause of the pain is removed.

[0029] “Neuropathic pain” is caused by an injury or dysfunction of the central or peripheral nervous system. This injury or dysfunction follows, for example, trauma (section or crushing of a nerve, etc.), hypoxia (stroke, compression of a nerve, etc.), a metabolic disease (diabetes), a neurodegenerative pathology, an infection (HIV) or exposure to a toxic agent (cancer chemotherapy).

[0030] “Nociplastic pain” results from an alteration of nociception, without the origin of the alteration being obvious (lesion, inflammation), without stimulation of peripheral nociceptors, or characterized nervous damage.

[0031] By way of example, the composition of the invention is suitable for use in a method of treating acute nociceptive pain such as post-traumatic pain (due to shock, cut, burn, fracture, etc.), pain resulting from a medical procedure (post-surgical, dressing change, suture, catheter placement, etc.), or pain linked to inflammation of a tissue or organ, for example in response to a metabolic dysfunction (gout), a tumor, an infection by a pathogen or the presence of a foreign body.

[0032] Furthermore, the composition of the invention is also suitable for use in a method of treating chronic nociceptive pain such as low back pain, rheumatoid arthritis, osteoarthritis, chronic primary orofacial pain, autonomic trigerminal headaches, chronic musculoskeletal pain, chronic post-operative pain (such as after amputation, thoracotomy, spinal surgery, etc.) or chronic post-traumatic pain (such as burns and musculoskeletal injuries, etc.).

[0033] For example, the composition of the invention is also suitable for use in a method of treating chronic peripheral neuropathic pain in indications such as cancer, iatrogenic neuropathies induced by chemotherapy, post-radiation or linked to chronic pathologies such as diabetes or AIDS. Among chronic neuropathic pain, there are for example surgical scars, peripheral sequelae pain, radiculopathies, trigerminal or post-shingles neuralgia, lesions of a peripheral nerve, polyneuropathy, neurodegeneration, multiple sclerosis, complex regional pain syndrome type I (soft tissue or bone lesions) or type II (nerve lesion) and mechanical or thermal allodynia, hyperpathia.

[0034] For example, the composition of the invention is also suitable for treating pruritus.

[0035] According to another example, the composition of the invention is also suitable for use in a method of treating chronic nociplastic pain such as fibromyalgia, endometriosis and algodystrophy.

[0036] Preferably, the pharmaceutical composition of the invention is for use in a method of treating inflammatory pain, post-surgical pain or neuropathic pain.

[0037] According to the invention, the term "topical use and action" means that the pharmaceutical composition is for local use, not systemic, and the active peptide ingredient of co-conotoxin is not intended to pass into the blood system.

[0038] "By cutaneous route" is meant the fact that the composition is administered by cutaneous route, at the skin level, with a view to a local action of its active peptide ingredient of co-conotoxin, as opposed to a route of administration involving a general, systemic action, with passage into the blood system. For the purposes of the invention, the term "cutaneous route" excludes transdermal or percutaneous routes. The term "cutaneous route" also does not imply parenteral routes of administration requiring, for example, the use of a needle injection through the skin and therefore excludes transcutaneous routes of administration of the subcutaneous type.

[0039] The term "nociceptors innervating the skin" means sensory receptors innervating the skin. Nociceptors are in the form of nerve fibers called "sensory fibers" having a free peripheral ending and a spinal ending. Nociceptors correspond in particular to the free nerve endings of the primary afferent nerves, which are capable of acquiring and then transmitting the stimuli generating painful sensitivity. These free endings are sensory receptors sensitive to mechanical and / or chemical and / or thermal stimuli which can be located in particular in the epidermis, the dermis and the hypodermis; we then speak of "free" cutaneous "endings" or "fibers" of the nociceptors innervating the skin.

[0040] The nociceptors innervating the skin are in direct contact with the environment and allow, following stimulation, the creation and then the transmission of an electrochemical signal called “nerve impulse” or “action potential”.

[0041] Nociceptors can be of three types: A[3, Aô “fibers” and C fibers.

[0042] The Aô fibers are myelinated and rapidly conduct the action potential (at a average speed of 20 m / s). The initial message carried by the Aô fibers corresponds to the first stage of the pain felt, which is an acute intense pain that fades quickly.

[0043] C fibers are unmyelinated and conduct the action potential more slowly than Aô fibers. The initial message carried by C fibers corresponds to the second stage of pain, which is a more diffuse, less intense, less localized pain that lasts longer.

[0044] The A[3 fibers are moderately myelinated and conduct the action potential at an average speed of 30 to 120 m / s.

[0045] The local administration, by cutaneous route, of the pharmaceutical composition of the invention comprising one or more peptide(s) of the co-conotoxin family is a non-invasive solution. Consequently, the composition of the invention advantageously makes it possible to overcome the infectious risks linked to an invasive parenteral route, in particular with a catheter, of the intraspinal or subcutaneous administration type.

[0046] It has been unexpectedly found that local administration, via the skin, of the composition of the invention comprising as active ingredient a co-conotoxin, for example MVIIA, near and at the level of the peripheral free endings of cutaneous nociceptors, makes it possible to eliminate the secondary risks observed with parenteral administration, in particular intraspinal administration, while retaining the known pain-relieving effect linked to an action on the Cavs.

[0047] Furthermore, according to other characteristics of the invention, the pain-relieving pharmaceutical composition of the invention has a peripheral analgesic effect involving a local action mechanism of said peptide(s) at the level of the free cutaneous A[3 and / or Aô and / or C endings of the nociceptors innervating the skin.

[0048] The term "cutaneous nociceptor" means all types of nociceptors, innervating the skin, responding to one or more stimuli of mechanical, thermal or chemical origin by the transmission of a nervous message perceived as a sensation of pain by the body.

[0049] Examples of "cutaneous nociceptors" innervating the skin include mechano-nociceptors, thermo-nociceptors or polymodal nociceptors.

[0050] “Mechano-nociceptors” respond and are sensitive to mechanical stimuli such as deformation, pressure, rupture, cutting or incision in the skin.

[0051] “Thermal nociceptors” respond and are sensitive to a variation in hot or cold temperature, perceived at the skin level.

[0052] “Polymodal nociceptors” respond and are sensitive to several mechanical, thermal or chemical stimuli.

[0053] Advantageously, the composition of the invention makes it possible to treat pain by a peripheral analgesic action of the co-conotoxin peptide(s), at the level of the free cutaneous endings of the A[3 and / or Aô and / or C fibers.

[0054] Indeed, the analgesic effect on the sensation of pain has been observed by simple administration, by cutaneous route, of the composition of the invention, comprising one or more co-conotoxin peptide(s). Thus, the analgesic effect obtained in the presence of the co-conotoxin peptide does not require its diffusion into the blood and a systemic action.

[0055] According to another characteristic of the anti-pain pharmaceutical composition of the invention, said peptide(s) target(s), physiologically, the free endings of the cutaneous nociceptors impacting the function of the voltage-dependent calcium channels called "Cav" involved in the generation and transmission of the nervous message at the origin of the sensation of pain, preferably N-type Cav voltage-dependent calcium channels, more preferably Cav2.2 voltage-dependent calcium channels.

[0056] According to an embodiment of the analgesic pharmaceutical composition of the invention, said active principle essentially comprises one or more peptide(s) selected from the following list of peptides: MVIIA of SEQ ID NO 1, MVIIB of SEQ ID NO 2, MVIIC of SEQ ID NO 2, MVIIC of SEQ ID NO 3, ID NO 4, GVIA of SEQ ID NO 5, GVIIA (SNX -178) of SEQ ID NO 6, GVIIB of SEQ ID NO 7, SVIA of SEQ ID NO 8, SVIA mutl of SEQ ID NO 9, SVIA mut2 of SEQ ID NO 10, SVIB of SEQ ID NO 11, SOVIA of SEQ ID NO 12, SOVIA of SEQ ID NO 13, CnVIIB of SEQ ID NO 14, CnVIIC of SEQ ID NO 15, CnVIIH of SEQ ID NO 16, Bu8 of SEQ ID NO 17, C116a of SEQ ID NO 18, Mo VIA of SEQ ID NO 19, MoVIB of SEQ ID NO 20, PnVIA of SEQ ID NO 21, PnVIB of SEQ ID NO 12 22, RsXXVIA of SEQ ID NO 23, TVIA of SEQ ID NO 24, CVIA of SEQ ID NO 25, CVIB of SEQ ID NO 26, CVIC of SEQ

[0057] ID NO 27, CVID of SEQ ID NO 28, CVIE of SEQ ID NO 29, CVIF of SEQ ID NO 30, RVIA of SEQ ID NO 31 and FVIA of SEQ ID NO 32, or one of their variant(s), natural or synthetic, functionally active, exhibiting between 80% and 99% sequence homology. Selon un mode de réalisation privilégié de la composition pharmaceutique de l'invention, ledit principe actif est constitué d'un ou plusieurs peptide(s) choisi(s) parmi la liste suivante de peptides : MVIIA de SEQ ID NO 1, MVIIB de SEQ ID NO 2, MVIIC de SEQ ID NO 3, MVIID de SEQ ID NO 4, GVIA de SEQ ID NO 5, GVIIA (SNX -178) de SEQ ID NO 6, GVIIB de SEQ ID NO 7, SVIA de SEQ ID NO 8, SVIA mutl de SEQ ID NO 9, SVIA mut2 de SEQ ID NO 10, SVIB de SEQ ID NO 11, SO3 de SEQ ID NO 12, CnVIIA de SEQ ID NO 13, CnVIIB de SEQ ID NO 14, CnVIIC de SEQ ID NO 15, CnVIIH de SEQ ID NO 16, Bu8 de SEQ ID NO 17, C116a de SEQ ID NO 18, Mo VIA de SEQ ID NO 19, MoVIB de SEQ ID NO 20, PnVIA de SEQ ID NO 21, PnVIB de SEQ ID NO 22, RsXXVIA de SEQ ID NO 23, TVIA de SEQ ID NO 24, CVIA de SEQ ID NO 25, CVIB de SEQ ID NO 26, CVIC de SEQ ID NO 27, CVID de SEQ ID NO 28, CVIE de SEQ ID NO 29, CVIF de SEQ ID NO 30, RVIA de SEQ ID NO 31 et FVIA de SEQ ID NO 32 , ou, un de leur(s) variant(s), naturel(s) ou synthetic(s),functionally active(s) exhibiting between 80% and 99% sequence homology.

[0058]

[0059] Table 1 below lists the aforementioned peptide sequences, which are either of natural or synthetic origin. SE Qi DN O Name Peptide sequences Comments 1 MVIIA CKGKGAKCSRLMYDCCTGSC RSGKC 2 MVIIB CKGKGASCHRTSYDCCTGSC NRGKC 3 MVIIC CKGKGAPCRKTMYDCCSGSC GRRGKC 4 MVIID CQGRGASCRKTMYNCCSGSC NRGRC 5 GVIA CKSXGSSCSXTSYNCCRSCNX YTKRCY 6 GVIIA (S NX-178) CKSXGTXCSRGMRDCCTSCL LYSNKCRRY X en position 4 et 7= 4-hydroxyproli ne 4Hyp 7 GVIIB CKSXGTXCSRGMRDCCTSCL SYSNKCRRY X en position 4 et 7= 4-hydroxyproli ne 4Hyp 8 SVIA CRSSGSXCGVTSICCGRCYRG KCT 9 SVIA mu tl CRPSGSPCGVTSICCGRCYRG KCT 10 SVIA mu t2 CRPSGSPCGVTSICCGRCSRG KCT 11 SVIB CKLKGQSCRKTSYDCCSGSC GRSGKC 12 SO3 CKAAGKPCSRIAYNCCTGSCR SGKC 13 CnVIIA CKGKGAXCTRLXYDCCHGSC SSSKGRC X en position 7= 4-hydroxyproline 4 Hyp X en position 12=oxomethionine 14 CnVIIB CKGKGASCRRTSYDCCTGSC RSGKC 15 CnVIIC CKGTGKXCSRIAYNCCTGSC RSGKC X en position 7= 4-hydroxyproline 4 Hyp 16 CnVIIH CKGKGAXCTRLXYDCCHGSC SSSKGRCG X en position 7= 4-hydroxyproline 4 Hyp X en position 12=oxométhionin e 17 Bu8 CKRKGSSCRRTSYDCCTGSCR NGKC 18 Cl 16a NCPAGCRSQGCCM 19 MoVIA CKPXGSKCSXSMRDCCTTCIS YTKRCRKYYN X en position 4 et 10= 4-hydroxypro line 4Hyp 20 MoVIB CKPXGSKCSXSMRDCCTTCIS YTKRCRKYY X en position 4 et 10= 4-hydroxypro line 4Hyp 21 PnVIA GCLEVDYFCGIPFANNGLCCS GNCVFVCTPQ 22 PnVIB DDDCEPPGNFCGMIKIGPPCC SGWCFFACA 23 RsXXVIA CKGQSCSSCSTKEFCLSKGSR LMYDCCTGSCCGVKTAGVT 24 TVIA CLSXGSSCSXTSYNCCRSCNX YSRKC CKSTGASCRRTSYDCCTGSCR SGRC 26 CVIB CKGKGASCRKTMYDCCRGSC RSGRC 27 CVIC CKGKGQSCSKLMYDCCTGSC SRRGKC 28 CVID CKSKGAKCSKLMYDCCSGSC SGTVGRC 29 CVIE CKGKGASCRRTSYDCCTGSC RSGRC 30 CVIF CKGKGASCRRTSYDCCTGSC RLGRC 31 RVIA CKPXGSXCRVSSYNCCSSCKS YNKKCG

[0060] Selon un exemple particulier de l'invention, le ou les peptides d'co-conotoxine cible(ent) specifiquement les Cav 2.2 et correspond au peptide MVIIA de SEQ ID NO 1 et / ou GVIA de SEQ ID NO 5 et / ou CVID de SEQ ID NO 28 pris seul, ou, en mélange.

[0061] For the purposes of the invention, the term "peptide" designates a chain of amino acids linked together by a peptide bond or amide bond. The term "amino acids" designates all amino acids known to those skilled in the art, both in their levorotatory (L) and dextrorotatory D form, preferably in their natural L form.

[0062] The standard 1-letter amino acid code is used in the figures to define the peptide sequence listing, as defined by Table 2 below.

[0063] Table 2: Symbol Definition Symbol Definition A Alanine F Phenylalanine R Arginine P Proline N Asparagine 0 Pyrrolysine D Aspartic Acid (Aspartate) S Serine C Cysteine ​​U Selenocysteine ​​Q Glutamine T Threonine E Glutamic Acid (Glutamate) W Tryptophan G Glycine Y Tyrosine H Histidine V Valine I Isoleucine B Aspartic Acid or Asparagi ne L Leucine Z Glutamine or Glutamic Acid K Lysine J Leucine or Isoleucine MM Methionine XA or R or N or D or C or Q or E or G or H or I or L or K or M or F or P or 0 or S or U or T or W or Y or V; unknown or other

[0064] The term "natural or synthetic variant" means an amino acid sequence, of natural or synthetic origin, having one or more amino acids modified with respect to one of SEQ ID NO 1 to SEQ ID NO 31. The variant may have "conservative" modifications, in which a substituted amino acid has similar structural or chemical properties, such as for example the replacement of leucine by isoleucine. A variant may also have "non-conservative" modifications, such as for example the replacement of a glycine by a tryptophan. Analogous minor variations may also include additions or deletions of amino acids, or both.

[0065] The term "functionally active variant" means a peptide sequence which retains the biological pain-relieving activity involving a local mechanism of action, at the level of the free cutaneous endings A[3 and / or Aô and / or C of the nociceptors innervating the skin, that is to say a peptide variant whose peripheral analgesic effect is preserved. A person skilled in the art is able to determine, using known computer programs or other methods of the state of the art, which amino acid residues can be substituted, inserted, deleted or modified without abolishing the analgesic effect observed following the administration, by the cutaneous route, of the composition of the invention comprising the peptide or its variant. The biological activity and the analgesic effect of the peptide, or its variant, can be tested by a person skilled in the art using known techniques for assessing the pain tolerance threshold such as, for example, the Hargreaves test (Menghon et al, 2017, DOI: 10.21769 / BioProtoc.2506) or the Von Frey test (Matthew JG Bradman et al, 2015, DOI: 10.1016 / j; jneumeth.2015.08.010).

[0066] The term "sequence identity" or "homology" refers to the sequence identity or sequence similarity between two polypeptides. When a position in the two peptide sequences being compared is occupied by the same amino acid monomer, then the peptides are homologous or identical at that position. The percentage of homology / identity between two sequences is a function of the number of matching positions shared by the two peptide sequences divided by the number of positions being compared multiplied by 100. For example, if 6 of the 10 positions in two sequences match then the two sequences are 60% identical. Generally, a comparison is performed when two peptide sequences are aligned to give maximum homology / identity.

[0067] According to a first embodiment of the composition of the invention, the peptide or its variant is a peptide of natural origin, extracted from a mollusc of the genus Conus.

[0068] Table 3 below gives for each peptide, of natural origin, the organism from which it is extracted.

[0069] Table 3:

[0070]

[0071] It should be noted that all of the co-conotoxins in Table 3 have the known physiological target of N-type Cavs, more particularly type Cav2.2.

[0072] According to a particular embodiment, the composition of the invention comprises one or more natural peptide(s), comprising or consisting of one or other of SEQ ID NO 1 to SEQ ID NO 31, or one of their natural variant(s), secreted by a mollusc of the genus Conus, as mentioned in Table 1.

[0073] According to another embodiment of the composition of the invention, said peptide(s) or their functionally active variant(s) is / are of synthetic origin.

[0074] Par exemple, les peptides synthétiques suivants, présentant des séquences telle que définie dans le tableau 1, sont susceptibles d'être utilisés dans l'invention : MVIIA de SEQ ID NO 1, MVIIB de SEQ ID NO 2, MVIIC de SEQ ID NO 3, MVIID de SEQ ID NO 4, GVIA de SEQ ID NO 5, GVIIA (SNX -178) de SEQ ID NO 6, GVIIB de SEQ ID NO 7, SVIA de SEQ ID NO 8, SVIA mutl de SEQ ID NO 9, SVIA mut2 de SEQ ID NO 10, SVIB de SEQ ID NO 11, SO3 de SEQ ID NO 12, CnVIIA de SEQ ID NO 13, CnVIIB de SEQ ID NO 14, CnVIIC de SEQ ID NO 15, CnVIIH de SEQ ID NO 16, Bu8 de SEQ ID NO 17, C116a de SEQ ID NO 18, Mo VIA de SEQ ID NO 19, MoVIB de SEQ ID NO 20, PnVIA de SEQ ID NO 21, PnVIB de SEQ ID NO 22, RsXXVIA de SEQ ID NO 23, TVIA de SEQ ID NO 24, CVIA de SEQ ID NO 25, CVIB de SEQ ID NO 26, CVIC de SEQ ID NO 27, CVID de SEQ ID NO 28, CVIE de SEQ ID NO 29, CVIF de SEQ ID NO 30, RVIA de SEQ ID NO 31 and FVIA de SEQ ID NO 32.

[0075] As an illustration and not a limitation of the invention, Table 4 gives examples of peptide variants, of synthetic origin, which are capable of being used in the composition of the invention.

[0076] Table 4:

[0077]

[0078] According to a preferred embodiment of the composition of the invention, said active ingredient is a co-conotoxin MVIIA of sequence SEQ ID NO 1; or; one of its variants, natural or synthetic, functionally active having between 80% and 99% sequence homology with SEQ ID NO 1.

[0079] Indeed, it has been shown that co-conotoxin, in particular of the synthetic MVIIA type, administered via the skin using a pharmaceutical composition of the invention, causes the blocking of Cav2.2 channels by acting locally at the level of the endings of the cutaneous sensory fibers and by reducing neuronal hyperexcitability in an inflammatory and physiological context.

[0080] Thus, local administration, via the skin, of the composition of the invention makes it possible to act on pain sensitivity, and to treat acute or chronic pain, of a nociceptive, neuropathic or nociplastic nature, in particular intense chronic inflammatory or neuropathic pain induced by chemotherapy, by exposing / applying the co-conotoxin to the peripheral rather than central synaptic endings than at the level of the synapses of the sensory fibers.

[0081] The composition of the invention, comprising co-conotoxin, is a peripheral analgesic, reducing or even eliminating the sensation of pain by a peripheral action of co-conotoxin at the level of the endings of the cutaneous sensory fibers expressing Cavs, in particular Cav 2.2.

[0082] Advantageously, the composition of the invention does not cause systemic exposure of the co-conotoxin, its diffusion in the bloodstream is limited. This results in a reduction or absence of side effects linked to the administration of the co-conotoxin by intraspinal route. Compared to the intraspinal route, local administration, by cutaneous route of the co-conotoxin via the composition of the invention did not present any acute toxicity or notable side effects, even at high concentrations of co-conotoxin in animals, as will be shown by the experimental results below.

[0083] The pharmaceutical composition, comprising a co-conotoxin, administered locally via the skin, is an alternative to known methods of treating severe chronic pain using co-conotoxins, which overcomes the problems of toxicity, the risks of infections and the side effects linked to intraspinal administration or other administration with systemic action.

[0084] According to a preferred embodiment of the invention, said pain-relieving pharmaceutical composition comprises, in mass percentage, relative to its total mass, between 0.0002% and 6% of said co-conotoxin peptide(s), preferably between 0.0004% and 4.1%.

[0085] In these proportions, no acute toxicity was observed in vivo in animals, after cutaneous application of the pain-relieving composition of the invention. In particular, the performance of the mice was evaluated by the horizontal bar test which analyzes the behavior of the mouse and its motor capacity to raise all four legs onto a horizontal bar after administration of the treatment. In addition, during the duration of the experiments, the behavior and general condition of the animals was also evaluated by the continuous visual observation test. Nevertheless, a person skilled in the art knows how to test the toxicity of the composition of the invention by any other known methods.

[0086] According to the invention, said pharmaceutical composition is in a pharmaceutically and dermatologically acceptable galenic form, for use by the cutaneous route and for topical action.

[0087] For the purposes of the invention, the “galenic form” or “pharmaceutical form” corresponds to the form in which the composition is presented (cream, ointment) which is specially designed for the route of administration for which the composition is intended (cutaneous route and topical action).

[0088] "Pharmaceutically acceptable" means that which is useful in the preparation of the composition and which is safe, stable, non-toxic biologically, nor otherwise undesirable and which is acceptable for human or animal pharmaceutical use.

[0089] The term "dermatologically acceptable" means compatibility with the skin, that is to say anything useful in the preparation of the composition which is non-toxic, following cutaneous administration to humans or animals, in particular by topical application. In other words, this corresponds to anything which can be applied to the skin and / or mucous membranes, without risk of causing a reaction such as, for example, an allergic or inflammatory reaction.

[0090] “Cutaneous use” means use for cutaneous administration by application to the skin and / or mucous membranes.

[0091] The term "topical action" means an action of the active ingredient of the composition, after direct application, on the skin and / or mucous membranes, preferably on the surface of the skin and / or mucous membranes, which is a non-systemic local action.

[0092] According to a preferred embodiment, said pain-relieving pharmaceutical composition is compatible with the skin, for direct cutaneous administration.

[0093] The composition of the invention may be in the form of creams, oil-in-water emulsions, water-in-oil or multiple emulsions, solutions, suspensions, or even powders, suitable for application to the skin. The composition of the invention may be more or less fluid and have the appearance of a cream, a lotion, a milk, a serum, an ointment, a gel, a paste or a mousse. It may also be in solid form, such as a stick, or be applied to the skin in the form of an aerosol.

[0094] Preferably, said pain-relieving pharmaceutical composition of the invention is in a galenic form of paste, ointment, cream, gel, balm, mousse, body milk, emulsion, solution, lotion or powder.

[0095] According to another aspect of the invention, the pain-relieving pharmaceutical composition comprises one or more excipients, chosen for example from pharmaceutically and dermatologically acceptable emollients, humectants, antioxidants, emulsifiers, surfactants.

[0096] The term "excipient" means all substances without impact on the physicochemical properties and the therapeutic action of the active ingredient, which are necessary for establishing the galenic form of the pain-relieving composition of the invention, not conferring its therapeutic properties but playing a role in its stability and its assimilation by the body for local administration and by the cutaneous route.

[0097] According to the invention, the excipients are inert and have no activity towards the co-conotoxin. The excipients do not in any way alter the biological action and the peripheral analgesic effect of the co-conotoxin, following its cutaneous application via the pain-relieving composition of the invention.

[0098] Of course, the person skilled in the art will take care to choose the nature of the excipients and their proportions, so that the advantageous therapeutic properties of the co-conotoxin or its variant are not, or not significantly, altered by the proposed addition.

[0099] According to the invention, these excipients can be used alone or in a mixture to formulate the composition of the invention for its local administration, via the skin, allowing topical use and action.

[0100] According to a particular embodiment of the invention, the pain-relieving composition is for use in the treatment of channelopathies, such as the treatment of channelopathies involving N-type calcium channels, preferably Cav2.2 N-type calcium channels.

[0101] The term “channelopathy” means a disease related to a dysfunction or alteration of one or more functions of membrane ion channels.

[0102] Preferably, the pharmaceutical composition of the invention is administered by spreading, via a localized massage action, on the hands and / or feet and / or the painful area of ​​skin to be treated for pain, at least twice a day, preferably morning and evening, preferably with a therapeutically effective amount of between 0.1 mg and 1000 mg, preferably between 3.8 and 396 mg of co-conotoxin peptide(s) / liter of pharmaceutical composition.

[0103] “Therapeutically effective amount” means the amount of peptide(s) sufficient or effective to prevent, treat (stop, prevent progression, inhibit, reduce or slow down) pain and its sensations, including the symptoms and diseases resulting therefrom.

[0104] According to the invention, the “therapeutically effective quantity” corresponds to the quantity of peptides to be administered to the surface of the skin by massage using the composition of the invention, making it possible to obtain a beneficial effect in the patient, reducing or eliminating their sensation of pain, while respecting the administration dosage.

[0105] The present invention is described in more detail by means of examples and scientific results demonstrating the effect of the composition of the invention. These should not, however, be considered as limiting the scope of the present invention.

[0106] Thus, other characteristics and advantages of the invention will emerge from this detailed description, with reference to the appended figures, in which:

[0107] - [Fig 1] [Fig 1] schematically represents an overview of the routes of transmission of the nervous message involved in the sensation of pain, with in particular the role of Cav2.2 in the spinal synaptic transmission of the pain signal in the absence of treatment ([Fig.lA]), after administration of ziconotide by intraspinal route ([Fig.lB]) or after administration of the composition of the invention by cutaneous route ([Fig.lC]),

[0108] - [Fig.2] [Fig.2] schematically represents a sectional view of the different layers of skin tissue, with the position of the sensory endings of cutaneous nociceptors,

[0109] - [Fig.3] [Fig.3] represents the number of action potentials / second traveling mouse saphenous nerve, measured in vitro, on a nerve-skin preparation treated with a solution of MVIIA or lidocaine before the addition of a cocktail of pro-inflammatory compounds,

[0110] - [Fig.4] [Fig.4] represents the effect of administration, intra-plantar or intrathecal, of a solution of MVIIA or morphine, on the pain threshold of mice, assessed in the Hargreaves test, in an in vivo model of inflammation with carrageenan,

[0111] - [Fig.5] [Fig.5] represents the number of action potentials / second traveling the mouse saphenous nerve as a function of time, measured in vivo in a carrageenan inflammation model in anesthetized animals, after local application, via the skin, of a cream composition of the invention comprising MVIIA and after thermal stimulation (Figure 5A) (infrared laser) or mechanical stimulation of the skin of the treated area (Figure 5B) (Von Frey test),

[0112] - [Fig.6] [Fig.6] represents the effect of the local application, by cutaneous route, of a cream composition of the invention comprising MVIIA, on the pain threshold, in an in vivo model of carrageenan inflammation, evaluated in the Hargreaves test,

[0113] - [Fig.7] [Fig.7] represents the effect of the local application, by cutaneous route, of a cream composition of the invention comprising MVIIA, on the pain threshold, in an in vivo model of post-surgical pain inflammation, after thermal stimulation in the Hargreaves test (Figure 7A) or after mechanical stimulation in the Von Frey test (Figure 7B),

[0114] - [Fig.8] Figure 8 represents the effect of local application, by cutaneous route, of a cream composition of the invention comprising MVIIA, on the pain threshold in an in vivo model of post-traumatic neuropathic pain, measured by the paw immersion test in cold water (Figure 8A) or in hot water (Figure 8B) or in response to mechanical stimulation in the Von Frey test (Figure 8C).

[0115] In a known manner, as visible in [Fig. 1A], the sensation of pain can have different origins. For example, at the level of the thumb 1, a pain message can be induced by a thermal stimulus 2 (example: burn), a chemical stimulus 3 (example: contact with an acid, a stinging or algogenic substance of the venom type; or the release of pro-inflammatory molecules or other chemical mediators by the injured tissues or the immune cells), or a mechanical stimulus 4 (example: pinching of the skin) or an event causing injury 5, or dysfunction of a tissue.

[0116] In [Fig.lA], in enlargement 1', at the level of the skin layers 6, the mechanical 4, thermal 2, chemical 3 (example: inflammatory cytokines 91 secreted by the immune cells 8) stimulation of the nociceptor receptors will lead to the modulation of the activity of ion channels and a membrane depolarization, or receptor potential 10'. The subsequent regulation of the sodium channels, the potassium channels and the Cav 7 will generate the action potentials 10 which will propagate to the spinal cord 11, then to the brain 12. They correspond to the nervous message which codes and transports the pain signal.

[0117] In enlargement 11', at the synapse 13 between the presynaptic afferent neuron NAP and the postsynaptic neuron NP, the nerve message will be transmitted to the postsynaptic neuron NP present in the spinal cord 11. In response to the electrical signal (action potentials 10), the N-type Cav 7 of the NAP, in particular the Cav2.2, open and allow extracellular calcium to enter. This results in an increase in the intracellular calcium concentration in the presynaptic afferent neuron NAP, which induces the fusion of the synaptic vesicles 14 with the plasma membrane and the release of excitatory neurotransmitters 15 into the synapse 13.These neurotransmitters 15 will act on their channel receptors 71 present on the postsynaptic neuron NP, which will lead to its depolarization and the generation of new action potentials 10 which will be propagated towards the brain 12, where they will be decoded and integrated and will induce the cognitive and emotional aspects of pain.

[0118] In a known manner, as visible in [Fig. 1B], the intraspinal administration 16 of ziconotide 17 in the cerebrospinal fluid, in the immediate vicinity of the presynaptic nerve terminal 11' of the primary NAP afferent neuron, blocks the opening of Cav 7 of type Cav2.2, reducing the influx of calcium into the neuron. Consequently, the neurotransmitters 15 are not released by the vesicles 14 in the synapse 13 and the propagation of the nerve signal to the postsynaptic neuron NP is blocked. Thus, the intraspinal administration 16 of ziconotide 17 makes it possible to attenuate the perception of pain by blocking the transmission of the nerve signal at the synapse 13.

[0119] Surprisingly, as visible in [Fig. IC], it has been shown that the pharmaceutical composition 18 of the invention comprising a co-conotoxin 19, administered locally, by cutaneous route 20, close to and at the level of the free endings of the cutaneous nociceptors, exhibits a peripheral analgesic effect involving a local action mechanism. The peripheral analgesic effect obtained by cutaneous administration 20 of the composition of the invention 18 suggests the involvement of Cav 7 of type Cav 2.2 at the level of the free endings of cutaneous nociceptors.

[0120] More specifically, the present invention has shown that administration, via the skin, at the level of the endings of cutaneous nociceptors impacts the generation and transmission of the nerve pain message, even though the co-conotoxin is not present near the spinal presynaptic nerve ending.

[0121] The present invention has made it possible to show that the administration of co-conotoxin by intraspinal route directly at the presynaptic terminal is not necessary to obtain an analgesic effect. Indeed, a local, non-systemic peripheral action of co-conotoxin, administered by cutaneous route, also makes it possible to limit the transmission of the nerve pain message as confirmed by the experimental results below.

[0122] As seen in [Fig.2], the sensory fiber endings of cutaneous nociceptors, for example of the Aô fiber or C fiber or A[3 fiber type, have projections into the dermis and epidermis. The present invention shows the role of these projections, in the presence of co-conotoxin, in a nociceptive pathway involving the Cavs and the emission of a pain signal.

[0123] Advantageously, the results of experiments below have shown that the local administration, via the skin, of the composition of the invention comprising a co-conotoxin peptide, impacts the propagation of the pain message, this by simple administration near the free endings of the cutaneous nociceptors.

[0124] In other words, the free nerve endings and projections of cutaneous nociceptors at the level of the epidermis and dermis are sensitive to co-conotoxin peptides, when they are applied locally using the composition of the invention via the cutaneous route.

[0125] Example of a pain-relieving pharmaceutical composition for local administration, via the skin.

[0126] Lipophilic emulsion:

[0127] Water, Liquid Paraffin, Paraffin, Sorbitan Isostearate, Petrolatum, Sorbitan Laurate, Hydrogenated Castor Oil, PEG-25, Beeswax, Hydrogenated Castor Oil, Polysorbate 20, Benzyl Alcohol, Magnesium Sulfate, Phenoxyethanol, Stearic Acid, Potassium Sorbate, Perfume, Citric Acid, Alpha-Alpha-Isomethyl Ionone, Alpha-Amylcinnamic Aldehyde, Benzyl Benzoate, Benzyl Salicylate, Limonene, which corresponds to a lipophilic emulsion, water in occlusive oil with emollient power, with a lipid content of 54% and water of 46% marketed under the name Excipial Lipocrème CR T / 50G and forming the cream support base, to which synthetic MVIIA is added in addition in solution at different concentrations.

[0128] The above composition is given as an example, without however limiting the scope of protection of the invention.

[0129] The experimental results below are intended to demonstrate the peripheral analgesic effect obtained by application to the skin of a composition of the invention, in particular by implementing the scientific tests and observations described below.

[0130] Principle of the Hargreaves test (thermal stimulation):

[0131] Thermal stimulation by infrared radiation consists of the Hargreaves plantar test which makes it possible to evaluate the thermal pain threshold. This test makes it possible to measure the nociceptive threshold of an animal, of the rodent type, whose plantar surface is subjected to an infrared thermal stimulus. The animals are placed in a transparent cage. An infrared beam makes it possible to locally stimulate the paw, in particular the inflamed paw. The pain threshold in response to this thermal stimulation is evaluated by measuring the paw withdrawal time or "withdrawal latency". A longer withdrawal latency after treatment means an increase in the nociceptive threshold and therefore an increased tolerance to pain. In the present invention, the implementation of the Hargreaves test is carried out in accordance with the protocol described in the publication by Menghon et al, 2017, DOI: 10.21769 / BioProtoc.2506, the contents of which must be considered as part of this application.

[0132] Principle of the Von Frey test (mechanical stimulation):

[0133] The Von Frey tactile sensitivity test (with a method for calculating Chaplan's tactile sensitivity described in the publication SR Chaplan et al, 1994, Journal of Neuroscience Methods, DOI: doi.org / 10.1016 / 0165-0270(94)90144-9) consists of placing rodent-type animals individually in cages with a wire mesh floor, then applying a painful model perpendicular to the paw, for example on a paw sensitized by inflammation, mechanical pressure by calibrated monofilaments of different mechanical forces. Any reaction of the animal such as withdrawal of the paw, licking or vocalization is considered a positive response, following perceived pain. In the present invention, the implementation of the Von Frey test is carried out in accordance with the protocol described in the publication of Matthew JG Bradman et al, 2015, DOI: 10.1016 / j; jneumeth.2015.08.010, the contents of which must be considered as part of this application.

[0134] Principle of the horizontal bar test (motor coordination):

[0135] This test consists of presenting a raised horizontal bar to an animal, of the rodent type, held by the tail so that it grasps it with its forelimbs, then measuring the time necessary for the animal to recover with its four supports on this bar. A drop in performance (increase in time necessary to recover) will suggest a potential adverse effect of the treatment on one or more physiological or behavioral functions such as motor coordination, muscle strength, motivation or alertness of the animal.

[0136] Principle of the visual observation test (side effect on behavior):

[0137] This test consists of regularly observing, during in vivo experiments, the general behavior of the mice in order to identify unforeseen and significant effects resulting from the treatment or procedure in progress. For example, it is observed whether the animal maintains normal movement or reaction activity or exhibits abnormal behavior. This test is carried out by a qualified experimenter who is familiar with the behaviors and normal activity expected in the animal. For example, behavior close to sedation or prostration, excessive grooming, random exploration or movement, piloerection, scratching, vocalizations, straightness / rigidity of the tail may be observed.

[0138] These tests were implemented in the experiments below. The results obtained show the effect of local administration, by cutaneous route, near the endings of the fibers of the cutaneous nociceptors of a pharmaceutical composition comprising MVIIA in a method of treating intense chronic inflammatory and neuropathic pain.

[0139] A) Demonstration of the effect of an MVIIA solution on the activity of peripheral sensitive fibers in response to inflammatory chemical stimulation, in an ex vivo electrophysiological peripheral model ([Fig.3])

[0140] The study aims to record the action potentials running through the saphenous nerve, on an ex vivo model of a dissected paw, after chemical stimulation of the internal face of the skin by an “inflammatory cocktail”, in the presence or absence of MVIIA or lidocaine.

[0141] The experiments were carried out on commercial male C57B1 / 6J mice (Janvier Labs) aged 5-8 weeks, with a total weight between 20-25g.

[0142] The measurement of the action potentials of the nerve ex vivo is carried out in a KREBS solution dedicated to this purpose.

[0143] MVIIA co-conotoxin is a solution of commercial MVIIA diluted in a suitable KREBS solution, which is at a concentration of 10 pM.

[0144] Lidocaine is a solution diluted in said KREBS solution at a concentration of 10 mM. Lidocaine serves as a positive control in this experiment. Lidocaine is known as a local anesthetic, inhibitor of any nerve impulse, acting by blocking voltage-dependent sodium channels.

[0145] The inflammatory context is simulated by a cocktail of pro-inflammatory compounds called “inflammatory cocktail” comprising a mixture of bradykinin, prostaglandin E2, serotonin, histamine and potassium chloride. The administration of the inflammatory cocktail stimulates different receptors and generates an increase in the frequency of emission of action potentials in the saphenous nerve.

[0146] After sacrificing the mice, a dissection and removal of the saphenous nerve with the skin are carried out. The measurement of the action potential is carried out directly ex vivo on the nerve-skin dissection.

[0147] The results obtained are visible in [Fig.3].

[0148] The neuronal activity, representative of a nervous message generated in response to inflammatory stimulation, results in the detection of action potentials which are measured using any device known to those skilled in the art.

[0149] [Fig.3] represents the emission frequency of action potentials as a function of time, measured in the nerve-skin model, after stimulation by the inflammatory soup, in the presence of MVIIA, lidocaine or the dilution solution (KREBS solution).

[0150] As seen in [Fig.3], in this ex vivo peripheral electrophysiological model, treatment with MVIIA solution has an inhibitory effect on the activity of the saphenous nerve stimulated by the inflammatory soup, just like the positive control lidocaine.

[0151] These results confirm that MVIIA has a peripheral neuroinhibitory effect on the endings of cutaneous sensory fibers stimulated by inflammatory or inflammation-mimicking molecules.

[0152] B) Effect of the administration, by intraplantar or intrathecal route, of a solution of MVIIA or morphine on the pain threshold in an in vivo inflammation model ([Fig.4])

[0153] On an in vivo inflammatory model, the study aims to measure the pain threshold in response to thermal stimulation (via the Hargreaves test), after induction of inflammation by carrageenan, and administration of an MVIIA solution either intra-plantarly or intrathecally.

[0154] The objective is to show that the peripheral and local intra-plantar injection of MVIIA, in the inflamed paw of an animal, induces a modification of the threshold of pain perceived in response to thermal stimulation.

[0155] The experiment implements the aforementioned Hargreaves test.

[0156] This experiment shows the difference in action of MVIIA on perceived pain, depending on the method of administration. The experiment shows the effect of MVIIA after a local intra-plantar injection in the periphery and the effect of a central intrathecal injection of MVIIA.

[0157] The experiments were carried out on commercial CD1 male and female mice (Janvier Labs) with a total weight between 20-25g.

[0158] In this experiment, the induction of inflammation is carried out by injecting into the left hind paw of mice in vivo a 2% carrageenan solution diluted in physiological serum so as to obtain an inflamed paw.

[0159] MVIIA co-conotoxin is a solution of commercial synthetic MVIIA diluted in physiological saline (0.9% NaCl). Morphine is also diluted in physiological saline. The physiological saline corresponds to the vehicle and serves as a negative control.

[0160] Morphine serves as a positive control, this substance being known as an inhibitor of the sensation of pain perceived in response to thermal stimulation.

[0161] For the experiment, the mice are placed individually in the Hargreaves test chambers for its implementation. The pain threshold of the mice is evaluated by thermal stimulation of the inflamed paw by the IR beam, before induction of inflammation (T-210), and 3 hours 30 minutes after induction of inflammation (peak inflammation of the paw) and application of the treatment (T0), then at different times after treatment with MVIIA, morphine or the control vehicle. The withdrawal time or latency time is measured every 15 min during the first hour after treatment, then every 30 min, as visible in [Fig.4].

[0162] As seen in [Fig.4], intraplantar administration of MVIIA leads to an increase in the withdrawal latency of the inflamed paw, in response to thermal stimulation. In particular, 30 min after treatment, the pain sensitivity observed for an intraplantar injection of 1500 pmol of MVIIA is comparable to that observed after the intraplantar injection of 10.5 nmol of morphine.

[0163] The results in [Fig.4] show that local peripheral administration of an MVIIA solution induces an analgesic effect in vivo.

[0164] In parallel with the results of [Fig.4] allowing the determination of the in vivo analgesic effect of the local application of MVIIA, the effect of the different treatments on the general behavior of the mice was evaluated, throughout the experiment, by implementing the horizontal bar test and the visual observation test mentioned above.

[0165] Under the conditions of the experiment in [Fig.4], no major behavioral changes were observed in the animal following intra-plantar treatment with MVIIA or morphine. On the contrary, the general behavior of the animal was negatively impacted when administered intrathecally with MVIIA or morphine. These results suggest a narrow therapeutic margin for these two treatments using the intrathecal administration route.

[0166] For the purposes of the invention, the therapeutic margin corresponds to the safety margin of a drug, that is to say to the difference between the therapeutic threshold of a drug (minimum concentration below which no activity is obtained) and its toxic threshold (maximum concentration beyond which adverse effects appear). Drugs with a narrow therapeutic margin are characterized by toxic concentrations close to effective concentrations.

[0167] During the experiment in [Fig.4], the visual observation test and the horizontal bar test were implemented. The results of these tests showed that the performance of animals treated with intraplantar injection of MVIIA did not decrease. No notable behavioral changes were observed in these two tests during the experiment.

[0168] These results suggest better tolerance of treatment by local injection of MVIIA by intraplantar route than by intrathecal route.

[0169] All of these results (Hargreaves test) demonstrate the peripheral analgesic action of intraplantar administration of MVIIA on the sensation of pain caused by thermal stimulation of an inflamed paw. Furthermore, during this experiment, the intraplantar application of a therapeutic dose of MVIIA does not have a significant effect on the general behavior of the animal or its performance in the horizontal bar test, contrary to what was observed after administration of MVIIA by intraspinal route, or of morphine. These results suggest an increase in the therapeutic margin of MVIIA administered by cutaneous route, at the periphery.

[0170] C) Effect of the administration, by cutaneous route, of a pharmaceutical composition of cream containing MVIIA according to the invention ([Fig.5]) on nerve signaling in vivo, in anesthetized animals, in models of thermal or mechanical hypersensitivity induced by inflammation

[0171] The study aims to test the effect of peripheral application, by the cutaneous route, of MVIIA in the form of a cream, in a carrageenan-induced inflammatory pain model in anesthetized animals. The effect of peripheral application is observed by measuring the action potentials traveling along the saphenous nerve in response to mechanical stimulation (Von Frey test) or thermal stimulation (application of an infrared laser).

[0172] In this experiment, in vivo, on an anesthetized animal, the behavioral response to mechanical stimulation caused by the Von Frey filament is replaced by a recording of the action potentials of the entire saphenous nerve on the partially dissected leg.

[0173] As seen in Figures 5A, the action potentials traveling along the saphenous nerve in response to nociceptive stimulation of the inflamed area are recorded in vivo in anesthetized animals. The action potentials of the saphenous nerve are recorded following thermal stimulation of approximately 50°C induced by a laser. infrared at the wavelength of 980 nm (Figure 5A) and during mechanical stimulation of the skin, innervated by the nerve, with a Von Frey filament calibrated to apply a force of 10.0 g (Figure 5B).

[0174] The experiments were carried out on commercial CD1 male and female mice (Janvier Labs) with a weight of 20-25g.

[0175] In this experiment, the induction of inflammation is carried out by intra-plantar injection into a mouse hind paw in vivo of a 2% carrageenan solution, diluted in physiological serum.

[0176] The anesthetic mixture consists of ketamine and xylazine diluted in physiological serum.

[0177] The administration of MVIIA is done by cutaneous route. MVIIA is presented in the form of a cream consisting of mixing, volume by volume, 1 / 3 of a solution of MVIIA diluted in water, with 2 / 3 of a cream carrier base “Excipial lipocrème CR T / 50G” of composition as above for respective final concentrations of MVIIA in the cream of 1.5pM, 0.15pM or 0.015pM. These mixtures represent specific examples of pharmaceutical composition according to the invention.

[0178] After induction of inflammation with intraplantar carrageenan, 100pL of the aforementioned pharmaceutical compositions are administered to the animal by cutaneous massage of the inflamed paw for 60 seconds. Then, the animals are anesthetized and positioned on a platform with demonstration of the saphenous nerve and the saphenous vein by partial dissection of the inflamed paw.

[0179] Recording of nerve action potentials is performed by stimulating the skin with a Von Frey filament calibrated at 10.0g or with the infrared laser (wavelength 980nm). The results are shown in Figures 5A and 5B.

[0180] The results show that in an in vivo inflammatory model, the local application, via the skin, of a composition of the invention in the form of a cream, induces a reduction in the frequency of emission of action potentials, at the highest dose, on the two types of stimulation, mechanical and thermal, applied to the inflamed skin.

[0181] The reduction in the measured electrical signal (frequency of action potentials) reflects a reduction in the generation and transmission of the nociceptive nerve message which will result in a reduction in the sensation of pain in the animal.

[0182] The application of a composition of the invention comprising MVIIA, in a localized manner, by cutaneous administration, makes it possible to reduce the electrical activity at the origin of the sensation of pain.

[0183] These results suggest the analgesic effect of cutaneous administration of MVIIA, certainly involving local inhibition of Cav2.2 at the peripheral level.

[0184] D) In ​​vivo effect of the administration, by cutaneous route, of a pharmaceutical composition of cream containing MVIIA according to the invention in a model of inflammatory pain with thermal stimulation (Hargreaves test) ([Fig.6])

[0185] The study aims to measure the analgesic effect induced by the peripheral and local administration, via the skin, of a pharmaceutical composition of the invention comprising MVIIA, on thermal hypersensitivity caused by inflammation, with evaluation of the nociceptive threshold by the aforementioned Hargreaves test.

[0186] The experiments are carried out on commercial male and female CD1 mice (Janvier Labs) aged 5 to 8 weeks and weighing 20 to 25g.

[0187] Induction of inflammation is done by intra-plantar injection of a 2% carrageenan solution so as to obtain an inflamed paw.

[0188] The administration of MVIIA is done by cutaneous route. MVIIA is presented in the form of a cream consisting of mixing, volume by volume, 1 / 3 of a solution of MVIIA diluted in water, with 2 / 3 of a cream carrier base “Excipial lipocrème CR T / 50G” of composition as above for final concentrations of 1.5pM, 0.15pM or 0.015pM. These mixtures represent specific examples of pharmaceutical composition according to the invention.

[0189] As a first positive control, a lidocaine cream with a final lidocaine concentration of 10 mM is prepared by mixing 1 / 3 water and 2 / 3 “Excipial lipocrème CR T / 50G” cream support base, then administered with a volume of 100pL on the inflamed paw by skin massage for approximately 1 minute.

[0190] As a 2nd positive control, morphine is diluted in physiological serum at a concentration of 26.3 mM for intraperitoneal injection at a dose of 10pL / g.

[0191] For the experiment, the mice are evaluated in the Hargreaves test device before, then 3h30 after induction of inflammation by intra-plantar injection of carrageenan in one of the hind paws. Then, 100pL of the aforementioned MVIIA pharmaceutical compositions and the different controls are administered to the animal by skin massage for approximately 60 seconds at the level of the inflamed paw or intraperitoneally for morphine. The pain threshold of the mice will then be regularly evaluated by thermal stimulation of the inflamed paw with the infrared beam. The paw withdrawal latency is measured every 15 min during the first hour post-treatment, then every 30 min during the remaining time of the experiment, as visible in [Fig.6].

[0192] As seen in [Fig.6], cutaneous application of MVIIA in cream form significantly increases the nociceptive threshold in mice, with a latency withdrawal of the inflamed paw equivalent to that observed before induction of inflammation, for example at T60 minutes.

[0193] A dose-effect of MVIIA applied in cream form is also visible with a maximum effect observed from the intermediate dose of 1.5 nmol of MVIIA. The effects of MVIIA are comparable to those observed with lidocaine (anesthetic) or with a high dose of morphine, while being more sustained over time.

[0194] Dose-response refers to the relationship between the dose and the observed biological effect. Increasing the dose may increase the intensity or severity of an effect. More specifically, dose-response refers to the relationship between the amount of exposure to a substance (dose) and the resulting changes in physiological functions or health (response).

[0195] These results demonstrate the efficacy of MVIIA in cutaneous application on thermal hypersensitivity induced by inflammation.

[0196] Throughout this experiment, the general condition and behavior of the mice was evaluated by the visual observation test and by measuring their performance in the horizontal bar test. The results obtained, in parallel with the Hargreaves test in [Fig.6], do not show any deviation in the behavior or general condition of the mice after treatment with MVIIA. No significant effect after treatment with MVIIA, whatever the dose applied, could be observed when performing the horizontal bar test or the visual observation test, unlike the treatment with morphine.

[0197] More specifically, in the horizontal bar test, no decrease in performance was observed in animals treated with MVIIA by cutaneous application, regardless of the dose applied. In particular, no decrease in performance was observed at the maximum dose tested, 10 times higher than the effective dose of 1.5 nmol. On the other hand, a significant alteration in the performance of mice treated with morphine could be observed in the horizontal bar test. Morphine by intraperitoneal route impacts, at the therapeutic doses tested, certain central or physiological functions of mice, unlike the tested doses of MVIIA by cutaneous administration.

[0198] All the results of the experiment in [Fig.6] (Hargreaves test, horizontal bar test, visual observation test) show that in an in vivo model of thermal hypersensitivity induced by inflammation, the cutaneous application of an MVIIA cream, at the doses tested (1.5 nmol) and (15 nmol), induces analgesia superior to the cream containing lidocaine (1 pmol). This analgesic effect is also comparable to the analgesia obtained by systemic (intraperitoneal) administration of a dose of morphine (7.5 mg / kg), without impact on the general condition and animal behavior. These results suggest an improved therapeutic margin compared to intrathecal administration of MVIIA.

[0199] These results confirm the analgesic effect that could be induced by inhibition of Cav2.2 at the peripheral level in an inflammatory model, without inducing significant side effects. The local (topical) application, by cutaneous route, of a pharmaceutical composition of the invention, facilitates the administration of the active principle of co-conotoxin, of type MVIIA, while avoiding the undesirable effects linked to an invasive route of administration of the intrathecal type.

[0200] E) Effect of the administration, by cutaneous route, on an in vivo model of post-surgical pain, of a pharmaceutical composition of cream containing MVIIA according to the invention with thermal and mechanical stimulation (Figures 7A and 7B)

[0201] The study aims to measure the analgesia induced following the administration, at the periphery of the body, by cutaneous route, of MVIIA in the form of a cream in an in vivo inflammatory model of post-surgical pain, with thermal stimulation (Hargreaves test Figure 7A) and mechanical stimulation (Von Frey test Figure 7B).

[0202] The experiments are carried out on commercial male and female mice (Janvier Labs) CD1 with a weight of 20-25g.

[0203] Post-surgical pain is induced by performing on each anesthetized animal (isoflurane) a surgical operation characterized by a subplantar incision and suture according to the known Brennan protocol (Brennan et al, 1996, DOI. 10.1016 / 0304-3959(95)01441-1) the contents of which must be considered as part of this application.

[0204] The administration of MVIIA is done by cutaneous route. MVIIA is presented in the form of a cream consisting of mixing, volume by volume, 1 / 3 of a solution of MVIIA diluted in water, with 2 / 3 of a cream carrier base “Excipial lipocrème CR T / 50G” of composition as above for respective final concentrations of MVIIA in the cream of 0.15 pM or 1.5 pM. These mixtures represent specific examples of pharmaceutical composition according to the invention.

[0205] After manual mixing, 100pL of one of the above-mentioned cream compositions are administered to the animal by cutaneous massage of the paw for 60 seconds, which corresponds to an applied quantity of 1.5 nmol or 0.15 nmol of MVIIA.

[0206] As an experimental control, the cream support base “Excipial lipocrème CR T / 50G”, with 1 / 3 water added volume to volume, is applied cutaneously under the same conditions.

[0207] Figure 7A: Measurement of the analgesic effect of MVIIA administered in cream form in a post-operative pain model (thermal modality: Hargreaves test)

[0208] The mice are placed in the Hargreaves test compartments. Then the measurement of the basic threshold, in response to thermal stimulation on the left hind paw, is carried out.

[0209] After determining the basic threshold, the mice are operated on according to the Brennan protocol and left to rest for 20 hours.

[0210] After this rest and 1 hour of conditioning in the Hargreaves test cage, the measurement of the nociceptive threshold is carried out at T0 by thermal stimulation.

[0211] Then, the mice are treated by skin massage with 100 μL of cream containing MVIIA, i.e. with an amount of 1.5 nmol or 0.15 nmol of MVIIA, or with the cream base control (vehicle).

[0212] After treatment and administration by cutaneous route, the analgesia is evaluated every 15 to 30 min by measuring the paw withdrawal latency in seconds under the effect of thermal stimulation.

[0213] The results are visible in Figure 7A and show an increase in the withdrawal latency time following the application of a composition of the invention, by cutaneous route. These results reflect an increase in the pain threshold in animals treated with a composition of the invention administered locally by cutaneous route.

[0214] Figure 7B: Measurement of the analgesic effect of MVIIA, administered in cream form, in a post-operative pain model (mechanical modality: Von Frey test and calculation of tactile sensitivity according to the Chaplan method)

[0215] The mice are put in the Von Frey test condition. The basic threshold of tactile sensitivity is determined by mechanical stimulation of the paw by filaments of increasing forces and calculated according to the Chaplan method (SR Chaplan et al, 1994, Journal of Neuroscience Methods, DOI: doi.org / 10.1016 / 0165-0270(94)90144-9) the content of which must be considered as part of the present application.

[0216] After determining the basic threshold, the mice are operated on according to the Brennan protocol and left to rest for 20 hours.

[0217] According to the Von Frey test, at time zero T0, the evaluation of the nociceptive threshold is carried out, by mechanical stimulation of the operated area, with filaments calibrated in accordance with the Von Frey test.

[0218] Then, the mice are treated by cutaneous massage of 100 μl of cream containing a quantity of 1.5 nmol or 0.15 nmol of MVIIA or with the cream base control. After treatment and administration by cutaneous route, the analgesia is evaluated every 30 min, by monofilaments calibrated in the Von Frey test and the sensitivity threshold calculated according to the Chaplan method.

[0219] The results presented in Figure 7B show an increase in withdrawal latency following the application of a composition of the invention by the cutaneous route.

[0220] In the experiments of Figure 7A and 7B, evaluating post-surgical thermal and mechanical sensitivity after cutaneous treatment with MVIIA, the general condition and behavior of the mice were monitored by the horizontal bar test and the visual observation test. In the context of these experiments, no deviations in the general condition and behavior of the treated animals were reported.

[0221] This study, which aimed to test MVIIA in the form of a pharmaceutical composition administered locally via the skin, on an in vivo model of post-operative pain with two stimulation modalities (thermal and mechanical), shows that this local administration method, via the skin, effectively induces an analgesic effect.

[0222] The pharmaceutical composition of the invention therefore induces an analgesic effect on post-surgical pain following local peripheral administration, via the skin.

[0223] F) Effect of the administration, by cutaneous route, on an in vivo model of traumatic neuropathic pain, of a pharmaceutical composition of cream containing MVIIA according to the invention, and evaluation of the thermal hypersensitivity with thermal stimulation of the immersion type of the paw at 10°C and 46°C (Figures 8A and 8B), or of the mechanical hypersensitivity (Von Frey test (Figure 8C)) resulting.

[0224] The study aims to measure the analgesia induced following peripheral administration, by the cutaneous route, of MVIIA in the form of a cream, in the in vivo model of chronic neuropathic pain induced by the spared nerve injury model, inducing allodynia (hypersensitivity) to thermal and mechanical stimulation.

[0225] Post-surgical neuropathic pain is induced by performing on each anesthetized animal a surgical operation to section the peroneal and tibial branches of the sciatic nerve as indicated in the publication by Anne Frédérique Bourquin et al, 2006, DOI: 10.1016 / j.pain.2005.10.036, the content of which is part of the present application.

[0226] This operation induces in a few days a mechanical and thermal hypersensitivity (allodynia) of the area innervated by the 3rd branch or sural nerve.

[0227] The experiments are carried out on commercial male and female mice (Janvier Labs) CD1 with a weight of 20-25g.

[0228] Ligation and section were performed under anesthesia (isoflurane) and the animals were left to recover with observation by the regular visual observation test. Evaluation of thermal or mechanical hypersensitivity was performed 14 days after induction of the model.

[0229] MVIIA is administered cutaneously. MVIIA is presented in the form of a cream consisting of a mixture, volume by volume, of 1 / 3 of a solution of MVIIA diluted in water, with 2 / 3 of a cream carrier base "Excipial lipocrème CR T / 50G » of composition as above for respective final concentrations of MVIIA in the cream at 1.5 pM or 0.15 pM. These mixtures represent specific examples of pharmaceutical composition according to the invention.

[0230] After mixing, 100pL of the cream are administered to the animal by cutaneous massage of the paw for 60 seconds, i.e. to administer a quantity of 1.5 nmol or 0.15 nmol of MVIIA

[0231] As an experimental control, the cream support base “Excipial lipocrème CR T / 50G”, added volume to volume of 1 / 3 water, called “vehicle” is applied cutaneously.

[0232] Figure 8A and 8B: Measurement of the analgesic effect on neuropathic pain in a model of induced hot and cold thermal allodynia (hypersensitivity) (10°C or 46°C) (nerve spared model)

[0233] A mouse hind paw is immersed in cold (10°C) or warm (46°C) water. Then the measurement of the basic threshold of the time of withdrawal of the immersed paw from the water is carried out.

[0234] After determining the baseline threshold, the mice are operated on to sever the peroneal and tibial branches of the sciatic nerve. After the operation, the mice are left to rest for 14 days where post-operative monitoring by the visual observation test is carried out.

[0235] After this rest, the evaluation of thermal sensitivity is carried out (time T0) by measuring the withdrawal latency of the paw immersed in water at 10°C or 46°C.

[0236] Then, the mice are treated by skin massage with 100 μL of one of the creams of the invention either with a dose of 0.15 nmol or 1.5 nmol of MVIIA, in parallel with a control cream devoid of MVIIA.

[0237] After treatment and administration by cutaneous route, the evaluation of the induced analgesia is carried out every 30 min, by measuring the paw withdrawal latency in seconds under the effect of thermal stimulation by immersion in cold water at 10°C or hot water at 46°C.

[0238] The results are visible in Figure 8A (immersion in water at 10°C) and Figure 8B (immersion in water at 46°C).

[0239] These results show an increase in withdrawal latency time in response to the application of a pharmaceutical composition of the invention by cutaneous route on induced post-operative neuropathic pain.

[0240] Figure 8C: Measurement of the analgesic effect via mechanical stimulation (Von Frey test) in the context of post-operative neuropathic pain

[0241] The Von Frey test is performed on mice.

[0242] Then the measurement of the basic threshold is carried out. The basic threshold corresponds to the measurement of the mechanical pain threshold, calculated according to the Chaplan method, involving to assess the withdrawal of the leg, in response to the application of Von Frey filaments of increasing forces.

[0243] After determining the baseline threshold, the mice are operated on to sever the peroneal and tibial branches of the sciatic nerve in accordance with the protocol of the aforementioned publication by Anne Frédérique Bourquin et al, 2006. After the operation, the mice are left to rest for 14 days where post-operative monitoring is carried out.

[0244] After this rest, the evaluation of tactile sensitivity at time zero T0 is carried out after mechanical stimulation by Von Frey filaments of increasing strength and according to the Chaplan calculation method.

[0245] Then, the mice are treated by skin massage with 100 μL of one of the creams of the invention either with a dose of 0.15 nmol or 1.5 nmol of MVIIA or with the cream base control (vehicle).

[0246] After treatment and administration by cutaneous route, the analgesia is evaluated every 30 min, by evaluating the force inducing the withdrawal of the paw subjected to mechanical stimulation by Von Frey filaments of increasing forces.

[0247] The results are visible in Figure 8C.

[0248] These results show an increase in pain tolerance following the application of a composition of the invention, via the skin, in a model of mechanical allodynia induced by post-traumatic neuropathy.

[0249] Throughout the experiment, the general condition and behavior of the animals were regularly observed according to the aforementioned visual observation test. No notable deviant or unusual behavior was detected in these experiments evaluating the general condition of the animals, whether in the animals treated with MVIIA or the control.

[0250] All the results in [Fig.8] show that local administration, via the skin, of a composition of the invention comprising MVIIA, in an in vivo model of post-traumatic neuropathic pain, generates an analgesic effect on the pain caused by immersion in cold or hot water, or by mechanical stimulation of the hypersensitive area.

[0251] Study of the bioavailability of MVIIA in plasma, following the application of a composition of the invention, by cutaneous route:

[0252] The concentration of MVIIA in the plasma of mice was studied after local cutaneous application of the compositions of the invention used in the above-mentioned experiments.

[0253] The concentration of MVIIA is measured by quantification of MVIIA in the plasma of the treated mice, as a function of time, by mass spectrometry according to any methods known to those skilled in the art.

[0254] The results obtained show that MVIIA is not detected in the plasma samples taken from the treated mice, with a detection threshold of the order of 10 nM.

[0255] Thus, the analgesic and pain-relieving effect after application, by the cutaneous route, of a composition of the invention, is obtained without the need for the MVIIA to be present in the plasma and without systemic exposure.

[0256] Thus, all of these experimental results show that the local application, via the skin, of a pain-relieving pharmaceutical composition comprising a co-conotoxin, in particular of the MVIIA type, in the form of a cream, intended for topical application to the skin, makes it possible to relieve intense chronic inflammatory and neuropathic pain, by a peripheral analgesic effect via the sensory endings of the cutaneous nociceptors, in particular involving the Cavs, in particular of the Cav2.2 type.

[0257] The present pain-relieving pharmaceutical composition, administered locally via the skin, therefore consists of an alternative solution to the intraspinal route of treatment of intense chronic pain by a co-conotoxin and to the use of opioids in general.

[0258] This new mode of administration of co-conotoxin, involving an analgesic effect peripheral, advantageously allows to avoid the undesirable effects and infectious risks linked to treatment using the intraspinal route, while allowing direct management of pain by the patient capable of easily administering the composition by skin massage.

Claims

Claims

1. Pain-relieving pharmaceutical composition for topical use and action, comprising as active ingredient, one or more peptide(s) of the co-conotoxin family, of natural or synthetic origin, or one of their natural or synthetic variant(s), functionally active, for use in a method of treating acute or chronic pain, of a nociceptive, neuropathic or nociplastic nature, such as intense chronic inflammatory and neuropathic pain, characterized in that it is in a pharmaceutically and dermatologically acceptable galenic form, for cutaneous use and topical action, said form being suitable for local administration, cutaneously, near and at the level of the free cutaneous endings of the nociceptors innervating the skin.

2. Pain-relieving pharmaceutical composition, according to the preceding claim, characterized in that it has a peripheral analgesic effect involving a local action mechanism, of said peptide(s), at the level of the free cutaneous endings A[3 and / or Aô and / or C of the nociceptors innervating the skin.

3. Pain-relieving pharmaceutical composition according to any one of the preceding claims, characterized in that said peptide(s) physiologically target(s) the free endings of cutaneous nociceptors impacting the function of the voltage-dependent calcium channels known as "Cav" involved in the generation and transmission of the nerve message causing the sensation of pain, preferably N-type Cav voltage-dependent calcium channels, more preferably Cav2.2 voltage-dependent calcium channels.

4. Pharmaceutical anti-pain composition, according to one of the previous claims, characterized by the fact that the main action is made up of one or more peptide(s) chosen from the following list of peptides: MVIIA of SEQ ID NO 1, MVIIB of SEQ ID NO 2, MVIIC of SEQ ID NO 3, MVIID de SEQ ID NO 4, GVIA de SEQ ID NO 5, GVIIA (SNX -178) de SEQ ID NO 6, GVIIB de SEQ ID NO 7, SVIA de SEQ ID NO 8, SVIA mutl de SEQ ID NO 9, SVIA mut2 de SEQ ID NO 10, SVIB de SEQ ID NO 11, SO3 de SEQ ID NO 12, CnVIIA de SEQ ID NO 13, CnVIIB de SEQ ID NO 14, CnVIIC of SEQ ID NO 15, CnVIIH of SEQ ID NO 16, Bu8 of SEQ ID NO 17, C116a of SEQ ID NO 18, Mo VIA of SEQ ID NO 19, MoVIB of SEQ ID NO 20, PnVIA of SEQ ID NO 21, PnVIB of SEQ ID NO 22, RsXXVIA of SEQ ID NO 23, TVIA of SEQ ID NO 24, CVIA of SEQ ID NO 25, CVIB of SEQ ID NO 26, CVIC of SEQ ID NO 27, CVID of SEQ ID NO 28, CVIE of SEQ ID NO 29, CVIF of SEQ ID NO 30, RVIA of SEQ ID NO 31 and FVIA of SEQ ID NO 32, or, one of their variant(s), natural(s) or synthetic(s), functionally active(s) exhibiting between 80% and 99% sequence homology.

5. Pain-relieving pharmaceutical composition according to any one of the preceding claims, characterized in that said active ingredient is a co-conotoxin MVIIA of sequence SEQ ID NO 1; or; one of its natural or synthetic, functionally active variants having between 80% and 99% sequence homology with SEQ ID NO 1.

6. Pain-relieving pharmaceutical composition according to any one of the preceding claims, characterized in that it comprises, in mass percentage, relative to its total mass, between 0.0002% and 6% of said co-conotoxin peptide(s), preferably between 0.0004% and 4.1%.

7. Pain-relieving pharmaceutical composition according to any one of the preceding claims, characterized in that it is in a galenic form of paste, ointment, cream, gel, balm, mousse, body milk, emulsion, solution, lotion or powder.

8. Pain-relieving pharmaceutical composition according to any one of the preceding claims, characterized in that it is in a galenic form suitable for being administered by spreading, via a localized massage action, on the hands and / or feet and / or the painful area of ​​skin to be treated for pain, at least twice a day, preferably morning and evening, preferably with a therapeutically effective amount of between 0.1 mg and 1000 mg, preferably between 3.8 and 396 mg of co-conotoxin peptide(s) / liter of pharmaceutical composition.

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