Bicyclic peptide ligands specific for epha2 and uses thereof

Abstract

The present invention relates to a Bicycle toxin conjugate BT5528, or pharmaceutically acceptable salts thereof, or pharmaceutical compositions thereof, and uses thereof.

Description

BICYCLIC PEPTIDE LIGANDS SPECIFIC FOR EphA2 AND USES THEREOFTECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to Bicycle toxin conjugates, or pharmaceutically acceptable salts thereof, or pharmaceutical compositions thereof. The present invention also provides uses of Bicycle toxin conjugates, or pharmaceutically acceptable salts thereof, or pharmaceutical compositions thereof, for preventing or treating a disease, disorder, or condition characterized by overexpression of EphA2 in diseased tissue.BACKGROUND OF THE INVENTION

[0002] Cyclic peptides are able to bind with high affinity and target specificity to protein targets and hence are an attractive molecule class for the development of therapeutics. In fact, several cyclic peptides are already successfully used in the clinic, as for example the antibacterial peptide vancomycin, the immunosuppressant drug cyclosporine or the anti-cancer drug octreotide (Driggers et al. (2008), Nat Rev Drug Discov 7 (7), 608-24). Good binding properties result from a relatively large interaction surface formed between the peptide and the target as well as the reduced conformational flexibility of the cyclic structures. Typically, macrocycles bind to surfaces of several hundred square angstrom, as for example the cyclic peptide CXCR4 antagonist CVX15 (400 A2; Wu et al. (2007), Science 330, 1066-71), a cyclic peptide with the Arg-Gly-Asp motif binding to integrin aVb3 (355 A2) (Xiong et al. (2002), Science 296 (5565), 151-5) or the cyclic peptide inhibitor upain-1 binding to urokinase-type plasminogen activator (603 A2; Zhao et al. (2007), J Struct Biol 160 (1), 1-10).

[0003] Due to their cyclic configuration, peptide macrocycles are less flexible than linear peptides, leading to a smaller loss of entropy upon binding to targets and resulting in a higher binding affinity. The reduced flexibility also leads to locking target-specific conformations, increasing binding specificity compared to linear peptides. This effect has been exemplified by a potent and selective inhibitor of matrix metalloproteinase 8, (MMP-8) which lost its selectivity over other MMPs when its ring was opened (Chemey et al. (1998), J Med Chem 41 (11), 1749- 51). The favorable binding properties achieved through macrocyclization are even more pronounced in multicyclic peptides having more than one peptide ring as for example in vancomycin, nisin and actinomycin.

[0004] Different research teams have previously tethered polypeptides with cysteine residues to a synthetic molecular structure (Kemp and McNamara (1985), J. Org. Chem; Timmerman et al. (2005), ChemBioChem). Meloen and co-workers had used tris(bromomethyl)benzene and related molecules for rapid and quantitative cyclisation of multiple peptide loops onto synthetic scaffolds for structural mimicry of protein surfaces (Timmerman et al. (2005), ChemBioChem). Methods for the generation of candidate drug compounds wherein said compounds are generated by linking cysteine containing polypeptides to a molecular scaffold as for example TATA (1,T,1"-(1,3,5- triazinane-l,3,5-triyl)triprop-2-en-l-one, Heinis etal. Angew Chem, Int Ed. 2014; 53:1602-1606).

[0005] Phage display-based combinatorial approaches have been developed to generate and screen large libraries of bicyclic peptides to targets of interest (Heinis et al. (2009), Nat Chem Biol 5 (7), 502-7 and WO 2009 / 098450). Briefly, combinatorial libraries of linear peptides containing three cysteine residues and two regions of six random amino acids (Cys-(Xaa)6-Cys-(Xaa)e-Cys) were displayed on phage and cyclised by covalently linking the cysteine side chains to a small molecule scaffold.SUMMARY OF THE INVENTION

[0006] According to one aspect, the invention provides a method for treating a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528.

[0007] In another aspect, the invention provides a method for treating a solid tumor in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528. The invention also provides BT5528 or a pharmaceutical composition comprising BT5528 for use in a method of treating a solid tumor in a human patient.

[0008] In another aspect, the invention provides a method for maintaining or reducing the volume of a solid tumor in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient.

[0009] In a further aspect, the invention provides BT5528, or a pharmaceutical composition comprising BT5528, for use in a method of treating a solid tumor in a patient, wherein the method comprises administering to the patient BT5528 or a pharmaceutical composition thereof.

[0010] In another aspect, the invention provides BT5528, or a pharmaceutical composition comprising BT5528, for use in a method of maintaining or reducing the volume of a solid tumorin a patient, wherein the method comprises administering to the patient BT5528 or a pharmaceutical composition comprising BT5528.

[0011] In another aspect, the invention provides BT5528 or a pharmaceutically acceptable salt thereof for use in the manufacture of a medicament for use in a method of treating a solid tumor in a patient, wherein the method comprises administering to the patient the BT5528.

[0012] In another aspect, the invention provides BT5528 or a pharmaceutically acceptable salt thereof of use in the manufacture of a medicament for use in a method of maintaining or reducing the volume of a solid tumor in a human patient, wherein the method comprises administering to the patient the BT5528.DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS1. Compounds and Definitions:

[0013] The term “BT5528,” as used herein, is a Bicycle toxin conjugate having a structure as shown below, wherein the molecular scaffold is l,l',l"-(l,3,5-triazinane-l,3,5-triyl)triprop-2-en- 1-one (TATA), and the peptide ligand comprises the amino acid sequence:(P-Ala)-Sano-A(HArg)D-Ci(HyP)LVNPLCiiLHP(D-Asp)W(HArg)Ciii (SEQ ID NO: 1) wherein Sar is sarcosine, HArg is homoarginine, and HyP is hydroxyproline.

[0014] As used herein, the term “pharmaceutically acceptable salt” refers to those salts which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response and the like, and are commensurate with a reasonable benefit / risk ratio. Pharmaceutically acceptable salts are well known in the art. For example, S. M. Berge et aL, describe pharmaceutically acceptable salts in detail in J. Pharmaceutical Sciences, 1977, 66, 1-19, incorporated herein by reference. Pharmaceutically acceptable salts of the compounds of this invention include those derived from suitable inorganic and organic acids and bases. Examples of pharmaceutically acceptable, nontoxic acid addition salts are salts of an amino group formed with inorganic acids such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid and perchloric acid or with organic acids such as acetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid or malonic acid or by using other methods used in the art such as ion exchange. Other pharmaceutically acceptable salts include adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate,cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate, glucoheptonate, glycerophosphate, gluconate, hemisulfate, heptanoate, hexanoate, 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, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, p-toluenesulfonate, undecanoate, valerate salts, and the like.BT5528

[0015] Salts derived from appropriate bases include alkali metal, alkaline earth metal, ammonium and N1(C i 4alkyl )4 salts. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like. Further pharmaceutically acceptable salts include, when appropriate, nontoxic ammonium, quaternary ammonium, and amine cations formed using counterions such as halide, hydroxide, carboxylate, sulfate, phosphate, nitrate, lower alkyl sulfonate and aryl sulfonate. It will be appreciated that salt forms are within the scope of this invention, and references to peptide ligands include the salt forms of said ligands.

[0016] The salts of the present invention can be synthesized from the parent compound that contains a basic or acidic moiety by conventional chemical methods such as methods described in Pharmaceutical Salts: Properties, Selection, and Use, P. Heinrich Stahl (Editor), Camille G. Wermuth (Editor), ISBN: 3-90639-026-8, Hardcover, 388 pages, August 2002. Generally, such salts can be prepared by reacting the free acid or base forms of these compounds with the appropriate base or acid in water or in an organic solvent, or in a mixture of the two.

[0017] As used herein, the term “about” shall have the meaning of within 10% of a given value or range. In some embodiments, the term “about” refers to within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1% of a given value.

[0018] Unless otherwise stated, structures depicted herein are also meant to include all isomeric (e.g., enantiomeric, diastereomeric, and geometric (or conformational)) forms of the structure; for example, the R and S configurations for each asymmetric center, Z and E double bond isomers, and Z and E conformational isomers. Therefore, single stereochemical isomers as well as enantiomeric, diastereomeric, and geometric (or conformational) mixtures of the present compounds are within the scope of the invention. Unless otherwise stated, all tautomeric forms of the compounds of the invention are within the scope of the invention. Additionally, unless otherwise stated, structures depicted herein are also meant to include compounds that differ only in the presence of one or more isotopically enriched atoms. For example, compounds having the present structures including the replacement of hydrogen by deuterium or tritium, or the replacement of a carbon by a13C- or14C-enriched carbon are within the scope of this invention. Such compounds are useful, for example, as analytical tools, as probes in biological assays, or as therapeutic agents in accordance with the present invention.2. Methods of Treatment

[0019] In one aspect, the invention provides a method, or a use, for treating a solid tumor in a human patient. In some embodiments, the solid tumor is an advanced malignancy, comprising administering to the patient BT5528 or a pharmaceutical composition comprising BT5528 to the patient. In some embodiments, the solid tumor or advanced tumor is associated with EphA2- expression.

[0020] In some embodiments, the methods of the invention comprise the administration of BT5528. In some embodiments, the methods of the invention comprise the administration of a pharmaceutically acceptable salt of BT5528. In some embodiments, the methods of the invention comprise the administration of a pharmaceutical composition comprising BT5528, or a pharmaceutically acceptable salt thereof

[0021] In some embodiments, the present invention provides methods for maintaining or reducing the volume of a solid tumor in a patient. In some embodiments, the invention provides methods for maintaining or reducing the volume of a solid tumor in a patient, wherein the method comprises the administration of BT5528 or a pharmaceutically acceptable salt thereof. In some embodiments, the invention provides methods for maintaining or reducing the volume of a solid tumor in a patient, wherein the method comprises the administration of a pharmaceutical composition comprising BT5528.

[0022] In some embodiments, maintaining the volume of a solid tumor refers to an increase in the volume of the tumor by no more than 75%, no more than 50%, no more than 25%, no more than 10% or no more than 5%. In some embodiments, maintaining the volume of a solid tumor refers to the volume of the tumor being unchanged.

[0023] In some embodiments, reducing the volume of a solid tumor refers to a reduction in the volume of the tumor by 100%, by at least 95%, at least 90%, at least 85%, at least 80%, at least 75% or at least 70%, at least 65%, at least 60%, at least 55%, at least 50%, at least 45%, at least 40%, at least 35%, at least 30%, at least 25%, at least 20%, at least 15%, at least 10% or at least 5%.

[0024] Optionally, the change in the volume of the tumor is a change relative to the volume of the tumor prior to the commencement of treatment.

[0025] In some embodiments, reference to a volume of a tumor may refer to a sum of volumes of two or more tumors in a patient (e.g. two, three, four, five, six, seven, eight, nine or ten or moretumors). In some embodiments, this can be determined by measuring the sum of an axis (e.g. a short axis or the longest diameter) of two or more solid tumors in the patient.

[0026] In some embodiments, reference to a volume of a tumor may refer to an average volume of two or more tumors in a patient (e.g. two, three, four, five, six, seven, eight, nine or ten or more tumors). In some embodiments, this can be determined by measuring the sum of an axis (e.g. a short axis or the longest diameter) of two or more solid tumors (e.g. two, three, four, five, six, seven, eight, nine or ten or more tumors) in the patient and dividing the sum by the number of tumors measured.

[0027] Thus, in some embodiments, maintaining or reducing the volume of a solid tumor in a patient as described herein may refer to maintaining or reducing the sum or average volume of two or more solid tumors (e.g. two, three, four, five, six, seven, eight, nine or ten or more tumors) in a patient.

[0028] Thus, in some embodiments, maintaining the volume of a solid tumor refers to an increase in the sum or average volume of two or more tumors (e.g. two, three, four, five, six, seven, eight, nine or ten or more tumors) of no more than 75%, no more than 50%, no more than 25%, no more than 10% or no more than 5%. In some embodiments, maintaining the volume of a solid tumor refers to the sum or average volume of the tumors being unchanged.

[0029] In some embodiments, reducing the volume of a solid tumor refers to a reduction in the sum or average volume of two or more tumors (e.g. two, three, four, five, six, seven, eight, nine or ten or more tumors) by 100%, by at least 95%, at least 90%, at least 85%, at least 80%, at least 75% or at least 70%, at least 65%, at least 60%, at least 55%, at least 50%, at least 45%, at least 40%, at least 35%, at least 30%, at least 25%, at least 20%, at least 15%, at least 10% or at least 5%.

[0030] Optionally, the change in the sum or average volume of the tumor is a change relative to the sum or average volume of the tumor prior to the commencement of treatment.

[0031] The volume of the tumor (or tumors) can be maintained or reduced for a period of time until disease progression is documented. In some embodiments, disease progression refers to a measurement of the volume of the tumor of greater than a 75% increase in the volume of the tumor relative to the volume of the tumor prior to the commencement of treatment. In some embodiments, disease progression refers to a measurement of the length of an axis of a tumor (or the sum or average of two or more tumors) of greater than 20%. Optionally, the volume of thetumor is maintained or reduced for at least 8 weeks, at least 9 weeks, at least 10 weeks, at least 11 weeks, at least 12 weeks, at least 13 weeks, at least 14 weeks at least 15 weeks, at least 16 weeks, at least 17 weeks, at least 18 weeks, at least 19 weeks, at least 20 weeks, at least 6 months, at least 9 months, at least 12 months, at least 15 months, at least 18 months, at least 21 months or at least 24 months.

[0032] In some embodiments, the volume of a solid tumor over time may be measured by determining the length of an axis of the tumor. In some embodiments, the volume of a solid tumor over time may be measured by determining the length of the longest diameter of the solid tumor. In some embodiments, the volume of a solid tumor over time may be measured by determining the length of the short axis of a tumor. By way of representative embodiment, a 20% increase in the length of an axis or diameter of a solid tumor corresponds to an increase in the volume of the solid tumor of approximately 75% (i.e. 1.23).

[0033] The length of an axis of a tumor may be determined, for example, by a CT scan slice, MRI scan slice, caliper measurement or X-ray.

[0034] In other embodiments, the volume of a solid tumor over time may be measured by volumetric assessment e.g. using a three-dimensional scan such as a CT scan or MRI scan.

[0035] In some embodiments, the treatment of a cancer or of a solid tumor may cause a complete response of the cancer or solid tumor to said treatment, i.e. the disappearance of all target lesions and all non-target lesions and normalization of tumor marker level. Optionally, the treatment of a cancer or solid tumor may cause a partial response of the cancer or solid tumor to said treatment, i.e. at least a 30% decrease in the sum of the lengths of an axis (e.g. the longest diameter (LD)) of the target lesions, taking as reference the baseline sum of the lengths of the axis (e.g. longest diameters) of the lesions. Optionally, the treatment of a cancer or solid tumor may result in stable disease, i.e. not more than a 30% decrease in the sum of the axis (e.g. LD), but less than a 20% increase in the sum of the axis (e.g. LD), with no new lesions.

[0036] 3. Combination Therapies

[0037] In some embodiments, the invention provides a combination use of BT5528 and an anti-PD-1 antibody or an anti-PD-Ll antibody, for treating a solid tumor. In some embodiments, a method of treatment of the present invention comprises the administration of BT5528, or apharmaceutical composition comprising BT5528, and the further administration of an anti-PD-1 antibody or an anti-PD-L 1 antibody to the human patient.

[0038] In some embodiments, the anti-PD-1 antibody is selected from the list consisting of pembrolizumab, nivolumab, cemiplimab, dostarlimab, retifanlimab, vopratelimab, spartalizumab, camrelizumab, sintilimab, tislelizumab, toripalimab, INCMGA00012, AMP-224, AMP-514 and acrixolimab.

[0039] In some embodiments, the anti-PD-L 1 antibody is selected from the list consisting of atezolizumab, avelumab, durvalumab, KN035 and cosibelimab.

[0040] In some embodiments, the methods of the invention comprise the administration of BT5528, or a pharmaceutical composition comprising BT5528, and the further administration of nivolumab to the human patent.

[0041] Nivolumab can be administered as described on the label, which can be found at https: / / www.opdivohcp.com / dosing / dosing-schedules, the content of which is incorporated herein by reference in its entirety. In some embodiments, Nivolumab is administered 240 mg every 2 weeks. In some embodiments, Nivolumab is administered 480 mg every 4 weeks. In some embodiments, Nivolumab is administered as a 30-minute IV infusion.

[0042] In some embodiments of a combination use, a patient is not previously known being intolerant to an immune checkpoint inhibitor. In some embodiments of a combination use, a patient is not known being hypersensitivity to checkpoint inhibitor therapy. In some embodiments of a combination use, a patient has no prior organ transplant. In some embodiments of a combination use, a patient is not previously diagnosed with clinically relevant immunodeficiency. In some embodiments of a combination use, a patient does not have active systemic infection requiring therapy. In some embodiments of a combination use, a patient does not take more than 10 mg daily prednisone equivalent or other strong immunosuppressant. In some embodiments of a combination use, a patient does not have a history of autoimmune disease except alopecia or vitiligo. In some embodiments of a combination use, a patient does not have a history of interstitial lung disease.

[0043] In some embodiments of a combination use, BT5528 or the pharmaceutical composition comprising BT5528 and nivolumab are administered separately. In some embodiments, BT5528 or the pharmaceutical composition comprising BT5528 and nivolumab are administered sequentially. In some embodiments, BT5528 or the pharmaceutical compositioncomprising BT5528 is administered first followed by nivolumab. In some embodiments, nivolumab is administered first followed by BT5528 or the pharmaceutical composition comprising BT5528.

[0044] In some embodiments, BT5528 and nivolumab are administered by separate infusions. In some embodiments, BT5528 and nivolumab are administered by sequential infusions. In some embodiments, BT5528 is administered by a first infusion followed by nivolumab. In some embodiments, nivolumab is administered by a first infusion followed by BT5528.4. General Description of Certain Embodiments of the Invention

[0045] In some embodiments, the methods of the invention comprise the administration of a pharmaceutical composition comprising BT5528, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient or carrier. In some embodiments, the pharmaceutical composition comprises about 21.2 mg BT5528, or a pharmaceutically acceptable salt thereof.

[0046] In some embodiments, the pharmaceutical composition is a solid pharmaceutical composition. In some embodiments, a solid pharmaceutical composition of the invention is powders. In some embodiments, a pharmaceutical composition of the invention is lyophilized powder. In some embodiments, a solid pharmaceutical composition of the invention is granules.

[0047] In some embodiments, the pharmaceutical composition is a liquid pharmaceutical composition. In some embodiments, a liquid pharmaceutical composition of the invention is a pharmaceutical formulation in an acceptable vehicle or solvent. In some embodiments, an acceptable vehicle or solvent is selected from sterile water, Ringer’s solution, U.S.P. and isotonic sodium chloride solution. In some embodiments, an acceptable vehicle or solvent is sterile water. In some embodiments, an acceptable vehicle or solvent is a sterile injectable medium. In some embodiments, a liquid pharmaceutical composition comprises about 2-4 mg / mL BT5528, or a pharmaceutically acceptable salt thereof.

[0048] In some embodiments, a pharmaceutically acceptable excipient or carrier comprises a buffering agent. In some embodiments, a buffering agent is selected from phosphates, glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinyl pyrrolidone, cellulose-based substances, polyethylene glycol, sodium carboxymethylcellulose, polyacrylates, waxes, polyethylene-polyoxypropylene-block polymers, polyethylene glycol andwool fat. In some embodiments, a buffering agent is histidine hydrochloride. In some embodiments, a buffering agent is sodium hydroxide. In some embodiments, a buffering agent is hydrochloric acid.

[0049] In some embodiments, a buffering agent is at an amount to adjust pH of a pharmaceutical composition of the invention to about 6-8. In some embodiments, a buffering agent is histidine hydrochloride at an amount of about 1-3 mg per mg of BT5528, or a pharmaceutically acceptable thereof. In some embodiments, histidine hydrochloride is at an amount of about 1.31 or 2.62 mg per mg of BT5528, or a pharmaceutically acceptable thereof. In some embodiments, a liquid pharmaceutical composition of the invention comprises histidine hydrochloride at a concentration of about 5.24 mg / mL.

[0050] In some embodiments, a liquid pharmaceutical composition of the invention is at a pH of about 6-8. In some embodiments, a liquid pharmaceutical composition of the invention is at a pH of about 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, or 8.0. In some embodiments, a liquid pharmaceutical composition of the invention is at a pH of about 6.5 or 7.0.

[0051] In some embodiments, a pharmaceutically acceptable excipient or carrier comprises an inert pharmaceutically acceptable excipient or carrier. In some embodiments, an inert pharmaceutically acceptable excipient or carrier is sodium citrate or dicalcium phosphate. In some embodiments, an inert pharmaceutically acceptable excipient or carrier is a filler or extender. In some embodiments, a filler or extender is starches, lactose, sucrose, glucose, mannitol, or silicic acid. In some embodiments, an inert pharmaceutically acceptable excipient or carrier is a binder. In some embodiments, a binder is carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidinone, sucrose, or acacia. In some embodiments, an inert pharmaceutically acceptable excipient or carrier is selected from sucrose, trehalose, dextrose, or a combination thereof. In some embodiments, an inert pharmaceutically acceptable excipient or carrier is sucrose.

[0052] In some embodiments, an inert pharmaceutically acceptable excipient or carrier (e.g., sucrose) is at an amount of about 10-35 mg per mg of BT5528, or a pharmaceutically acceptable thereof. In some embodiments, an inert pharmaceutically acceptable excipient or carrier (e.g., sucrose) is at an amount of about 15 or 30 mg per mg of BT5528, or a pharmaceutically acceptable thereof. In some embodiments, a liquid pharmaceutical composition comprises an inertpharmaceutically acceptable excipient or carrier (e.g., sucrose) at a concentration of about 60 mg / mL.

[0053] In some embodiments, a pharmaceutically acceptable excipient or carrier comprises a surfactant. In some embodiments, a surfactant is a polysorbate (e.g., polysorbate-20, polysorbate- 40, polysorbate-60, polysorbate-65, polysorbate-80, polysorbate-85, or a combination thereof). In some embodiments, a surfactant is selected from poloxamers (e.g., poloxamer 188); Triton™; sodium dodecyl sulfate (SDS); sodium laurel sulfate; sodium octyl glycoside; lauryl-sulfobetaine, myristyl-sulfobetaine, linoleyl-sulfobetaine, stearyl-sulfobetaine, lauryl-sarcosine, myristylsarcosine, linoleyl-sarcosine, stearyl-sarcosine, linoleyl-betaine, myristyl- betaine, cetyl-betaine, lauroamidopropyl-betaine, cocamidopropyl-betaine, linoleamidopropyl-betaine, myristamidopropyl-betaine, palmidopropyl- betaine, isostearamidopropyl-betaine (e.g. lauroamidopropyl), myristamidopropyl-, palmidopropyl-, or isostearamidopropyl- dimethylamine; sodium methyl cocoyl-, or disodium methyl ofeyl-taurate; and the Monaquat™ series (Mona Industries, Inc., Paterson, N.J. ), poly ethyl glycol, polyp ropyl glycol, and copolymers of ethylene and propylene glycol (e.g. pluronics, PF68). In some embodiments, a surfactant is Polysorbate 20.

[0054] In some embodiments, a surfactant (e.g., Polysorbate 20) is at an amount of about 0.01- 0.15 mg per mg of BT5528, or a pharmaceutically acceptable thereof. In some embodiments, a surfactant (e.g., Polysorbate 20) is at an amount of about 0.025, 0.05, or 0.1 mg per mg ofBT5528, or a pharmaceutically acceptable thereof. In some embodiments, a liquid pharmaceutical composition comprises a surfactant (e.g., Polysorbate 20) at a concentration of about 0.1 or 0.2 mg / mL.

[0055] In some embodiments, a pharmaceutically acceptable excipient or carrier comprises an isotonicity adjusting agent. In some embodiments, an isotonicity adjusting agent is sodium chloride, dextrose, calcium chloride, or a combination thereof. In some embodiments, an isotonicity adjusting agent is dextrose. In some embodiments, an isotonicity adjusting agent is sodium chloride. In some embodiments, an isotonicity adjusting agent is a combination of sodium chloride and dextrose.

[0056] In some embodiments, the invention provides a pharmaceutical composition comprising BT5528, or a pharmaceutically acceptable salt thereof, histidine hydrochloride,sucrose, and Polysorbate 20. In some embodiments, a pharmaceutical composition of the invention comprises:BT5528, or a pharmaceutically acceptable salt thereof; about 1.31-2.62 mg histidine hydrochloride per mg of BT5528, or a pharmaceutically acceptable thereof; about 15-30 mg sucrose per mg of BT5528, or a pharmaceutically acceptable thereof; and about 0.05-0.1 mg Polysorbate 20 per mg of BT5528, or a pharmaceutically acceptable thereof.

[0057] In some embodiments, the invention provides a solid pharmaceutical composition, which is a lyophilized powder, comprising: about 21.2 mg BT5528, or a pharmaceutically acceptable salt thereof; about 55.5 mg histidine hydrochloride per mg of BT5528, or a pharmaceutically acceptable thereof; about 636 mg sucrose per mg of BT5528, or a pharmaceutically acceptable thereof; and about 1.06-2.12 mg Polysorbate 20 per mg of BT5528, or a pharmaceutically acceptable thereof.

[0058] In some embodiments, the invention provides a solid pharmaceutical composition, which is a lyophilized powder, comprising: about 21.2 mg BT5528, or a pharmaceutically acceptable salt thereof; about 27.8 mg histidine hydrochloride per mg of BT5528, or a pharmaceutically acceptable thereof; about 318 mg sucrose per mg of BT5528, or a pharmaceutically acceptable thereof; and about 1.06 mg Polysorbate 20 per mg of BT5528, or a pharmaceutically acceptable thereof.

[0059] In some embodiments, the invention provides a liquid pharmaceutical composition comprising: about 2-4 mg / mL BT5528, or a pharmaceutically acceptable salt thereof; about 5.25 mg / mL histidine hydrochloride; about 60 mg / mL sucrose; andabout 0.1 -0.2 mg / mL Polysorbate 20.

[0060] In some embodiments, the invention provides a liquid pharmaceutical composition prepared by dissolving a solid pharmaceutical composition of the invention in water. In some embodiments, the invention provides a liquid pharmaceutical composition prepared by dissolving a solid pharmaceutical composition of the invention in an injectable medium (e.g., saline or 5% dextrose). In some embodiments, the invention provides a liquid pharmaceutical composition prepared by reconstitute a solid pharmaceutical composition of the invention in water, followed by dilution with 5% dextrose. In some embodiments, a liquid pharmaceutical composition is diluted into a 5% dextrose IV bag for IV administration. In some embodiments, a liquid pharmaceutical composition in a 5% dextrose IV bag is stored under room temperature (about 20- 25°C) for up to about 4 hours before IV administration. In some embodiments, a liquid pharmaceutical composition in a 5% dextrose IV bag is stored under refrigerated (about 2-8°C) conditions for up to about 20 hours before IV administration. In some embodiments, a liquid pharmaceutical composition in a 5% dextrose IV bag is stored under refrigerated (about 2-8°C) conditions for up to about 20 hours, followed by storage under room temperature (about 20-25°C) for up to about 4 hours, before IV administration.

[0061] In some embodiments, the invention provides a solid pharmaceutical composition comprising BT5528, or a pharmaceutically acceptable salt thereof, histidine hydrochloride, sucrose, Polysorbate 20, and dextrose. In some embodiments, the invention provides a liquid pharmaceutical composition comprising BT5528, or a pharmaceutically acceptable salt thereof, histidine hydrochloride, sucrose, Polysorbate 20, dextrose, and water. In some embodiments, the components of the pharmaceutical compositions are at the amount, concentration, and ratio as described above.

[0062] In some embodiments, a method of the invention comprises administering to a patient intravenously a pharmaceutical composition as described herein. In some embodiments, a pharmaceutical composition of the invention is administered by an IV injection. In some embodiments, a pharmaceutical composition of the invention is administered by an IV infusion. In some embodiments, an IV infusion of a pharmaceutical composition of the invention lasts about 5-30 minutes. In some embodiments, an IV infusion of a pharmaceutical composition of the invention lasts about 30-90 minutes. In some embodiments, an IV infusion of a pharmaceutical composition of the invention lasts about 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90 minutes.In some embodiments, an IV infusion of a pharmaceutical composition of the invention lasts about 60 minutes. In some embodiments, an IV infusion of a pharmaceutical composition of the invention lasts about 2, 2.5, 3, 3.5, or 4 hours.5. Dosage Regimens

[0063] In some embodiments, BT5528 or a pharmaceutical composition comprising BT5528 is administered to a patient once every 1, 2, 3, 4, 5, 6, or 7 days. In some embodiments, a pharmaceutical composition of the invention is administered to a patient weekly. In some embodiments, a pharmaceutical composition of the invention is administered to a patient once every two weeks.

[0064] In some embodiments, a treatment cycle is 4 weeks, i.e., a 28-day treatment cycle. In some embodiments, BT5528 is administered weekly on a 28-day treatment cycle, for example, on days 1, 8, 15, and 22. In some embodiments, BT5528 is administered once every two weeks on a 28-day cycle, for example, on days 1 and 15. In some embodiments, BT5528 is administered as a liquid formulation or a liquid unit dosage form.

[0065] In some embodiments, a treatment cycle is 3 weeks, i.e., a 21 -day treatment cycle. In some embodiments, BT5528 is administered in week 1 and week 2, but not in week 3, of a 21 -day treatment cycle. In some embodiments, BT5528 is administered on days 1 and 8 of a 21 -day treatment cycle. In some embodiments, BT5528 is administered once weekly of a 21-day treatment cycle. In some embodiments, BT5528 administered on days 1, 8, and 15 of a 21-day treatment cycle.

[0066] In some embodiments, BT5528 is administered at a dose (measured by the amount of the API: BT5528) of about 1-27 mg / m2. In some embodiments, BT5528 is administered at a dose of about 2-20 mg / m2. In some embodiments, BT5528 is administered at a dose of about 2-15 mg / m2. In some embodiments, BT5528 is administered at a dose of about 2-10 mg / m2. In some embodiments, BT5528 is administered at a dose of about 4-8 mg / m2, optionally at a dose of about 5-7 mg / m2, optionally at a dose of about 6.5 mg / m2. In some embodiments, BT5528 is administered at a dose of about 3-7 mg / m2, optionally at a dose of about 4-6 mg / m2, optionally at a dose of about 5 mg / m2. In some embodiments, BT5528 is administered at a dose of about 2.2, 4.4, 7.3, 11, 14.6, or 19.4 mg / m2. In some embodiments, BT5528 is administered at a dose of about 1.5-3.5, 3.5-5.5, 6.5-8.5, 10-12, 13.5-15.5, or 18.5-20.5 mg / m2. In some embodiments,BT5528 is administered at a dose of about 1-10 or 10-20 mg / m2. In some embodiments, BT5528 is administered at a dose of about 21, 22, 23, 24, 25, 26, or 27 mg / m2.

[0067] In some embodiments, the methods of the invention comprise administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient every two weeks at a dose of about 4-8 mg / m2, optionally a dose of about 5-7 mg / m2, optionally a dose of about 6.5 mg / m2.

[0068] In some embodiments, the methods of the invention comprise administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient weekly at a dose of about 3-7 mg / m2, optionally at a dose of about 4-6 mg / m2, optionally at a dose of about 5 mg / m2.

[0069] In some embodiments, the invention provides a method for treating a solid tumor in a human patient, comprising administering BT5528 to the patient every two weeks at a dose of about 4-8 mg / m2, optionally a dose of about 5-7 mg / m2, optionally a dose of about 6.5 mg / m2.

[0070] In some embodiments, the invention provides a method for treating a solid tumor in a human patient, comprising administering BT5528 to the patient weekly at a dose of about 3-7 mg / m2, optionally at a dose of about 4-6 mg / m2, optionally at a dose of about 5 mg / m2.

[0071] In some embodiments, the methods of the invention comprise administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient every two weeks at a dose of about 6.5 mg / m2.

[0072] In some embodiments, the methods of the invention comprise administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient weekly at a dose of about 5 mg / m2.

[0073] In some embodiments, the invention provides a method for treating a solid tumor in a human patient, comprising administering BT5528 to the patient every two weeks at a dose of about 6.5 mg / m2.

[0074] In some embodiments, the invention provides a method for treating a solid tumor in a human patient, comprising administering BT5528 to the patient weekly at a dose of about 5 mg / m2.

[0075] In some embodiments, the invention provides a method for treating urothelial cancer in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient every two weeks at a dose of about 4-8 mg / m2, optionally at a dose of about 5-7 mg / m2, optionally at a dose of about 6.5 mg / m2. In some embodiments, the urothelial cancer is EphA2-positive, i. e. is associated with EphA2 expression.

[0076] In some embodiments, the invention provides a method for treating urothelial cancer in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient weekly at a dose of about 3-7 mg / m2, optionally at a dose of about 4-6 mg / m2, optionally at a dose of about 5 mg / m2. In some embodiments, the urothelial cancer is EphA2 -positive, i.e. is associated with EphA2 expression.

[0077] In some embodiments, the invention provides a method for treating urothelial cancer in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient every two weeks at a dose of about 6.5 mg / m2. In some embodiments, the urothelial cancer is EphA2 -positive, i.e. is associated with EphA2 expression.

[0078] In some embodiments, the invention provides method for treating urothelial cancer in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient weekly at a dose of about 5 mg / m2. In some embodiments, the urothelial cancer is EphA2 -positive, i.e. is associated with EphA2 expression.

[0079] In some embodiments, the invention provides a method for treating ovarian cancer in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient every two weeks at a dose of about 4-8 mg / m2, optionally at a dose of about 5-7 mg / m2, optionally at a dose of about 6.5 mg / m2. In some embodiments, the ovarian cancer is EphA2 -positive, i. e. is associated with EphA2 expression.

[0080] In some embodiments, the invention provides a method for treating ovarian cancer in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient weekly at a dose of about 3-7 mg / m2, optionally at a dose of about 4-6 mg / m2, optionally at a dose of about 5 mg / m2. In some embodiments, the ovarian cancer is EphA2- positive, i.e. is associated with EphA2 expression.

[0081] In some embodiments, the invention provides a method for treating ovarian cancer in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient every two weeks at a dose of about 6.5 mg / m2. In some embodiments, the ovarian cancer is EphA2-positive, i. e. is associated with EphA2 expression.

[0082] In some embodiments, the invention provides a method for treating ovarian cancer in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient weekly at a dose of about 5 mg / m2. In some embodiments, the ovarian cancer is EphA2 -positive, i.e. is associated with EphA2 expression.

[0083] In some embodiments, the invention provides a method for treating non-small cell lung cancer (NSCLC) in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient every two weeks at a dose of about 4-8 mg / m2, optionally at a dose of about 5-7 mg / m2, optionally at a dose of about 6.5 mg / m2. In some embodiments, the NSCLC is EphA2 -positive, i.e. is associated with EphA2 expression.

[0084] In some embodiments, the invention provides a method for treating NSCLC in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient weekly at a dose of about 3-7 mg / m2, optionally at a dose of about 4-6 mg / m2, optionally at a dose of about 5 mg / m2. In some embodiments, the NSCLC is EphA2 -positive, i.e. is associated with EphA2 expression.

[0085] In some embodiments, the invention provides a method for treating NSCLC cancer in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient every two weeks at a dose of about 6.5 mg / m2. In some embodiments, the NSCLC is EphA2 -positive, i.e. is associated with EphA2 expression.

[0086] In some embodiments, the invention provides a method for treating NSCLC in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient weekly at a dose of about 5 mg / m2. In some embodiments, the NSCLC is EphA2- positive, i.e. is associated with EphA2 expression.

[0087] In some embodiments, the invention provides a method for treating head and neck cancer in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient every two weeks at a dose of about 4-8 mg / m2, optionally at a dose of about 5-7 mg / m2, optionally at a dose of about 6.5 mg / m2. In some embodiments, the head and neck cancer is EphA2-positive, i. e. is associated with EphA2 expression.

[0088] In some embodiments, the invention provides a method for treating head and neck cancer in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient weekly at a dose of about 3-7 mg / m2, optionally at a dose of about 4-6 mg / m2, optionally at a dose of about 5 mg / m2. In some embodiments, the head and neck cancer is EphA2 -positive, i.e. is associated with EphA2 expression.

[0089] In some embodiments, the invention provides a method for treating head and neck cancer in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient every two weeks at a dose of about 6.5 mg / m2. In someembodiments, the head and neck cancer is EphA2 -positive, i.e. is associated with EphA2 expression.

[0090] In some embodiments, the invention provides a method for treating head and neck cancer in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient weekly at a dose of about 5 mg / m2. In some embodiments, the ovarian cancer is EphA2-positive, i. e. is associated with EphA2 expression.

[0091] embodiments, the invention provides a method for treating gastric or upper GI cancer in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient every two weeks at a dose of about 4-8 mg / m2, optionally at a dose of about 5-7 mg / m2, optionally at a dose of about 6.5 mg / m2. In some embodiments, the gastric or upper GI cancer is EphA2 -positive, i.e. is associated with EphA2 expression.

[0092] In some embodiments, the invention provides a method for treating gastric or upper GI cancer in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient weekly at a dose of about 3-7 mg / m2, optionally at a dose of about 4-6 mg / m2, optionally at a dose of about 5 mg / m2. In some embodiments, the gastric or upper GI cancer is EphA2 -positive, i.e. is associated with EphA2 expression.

[0093] In some embodiments, the invention provides a method for treating gastric or upper GI cancer in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient every two weeks at a dose of about 6.5 mg / m2. In some embodiments, the gastric or upper GI cancer is EphA2 -positive, i.e. is associated with EphA2 expression.

[0094] In some embodiments, the invention provides a method for treating gastric or upper GI cancer in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient weekly at a dose of about 5 mg / m2. In some embodiments, the gastric or upper GI cancer is EphA2 -positive, i.e. is associated with EphA2 expression.

[0095] In some embodiments, the invention provides a method for treating triple negative breast cancer (TNBC) in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient every two weeks at a dose of about 4-8 mg / m2, optionally at a dose of about 5-7 mg / m2, optionally at a dose of about 6.5 mg / m2. In some embodiments, the TNBC is EphA2 -positive, i.e. is associated with EphA2 expression.

[0096] In some embodiments, the invention provides a method for treating TNBC in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient weekly at a dose of about 3-7 mg / m2, optionally at a dose of about 4-6 mg / m2, optionally at a dose of about 5 mg / m2. In some embodiments, the TNBC is EphA2 -positive, i.e. is associated with EphA2 expression.

[0097] In some embodiments, the invention provides a method for treating TNBC in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient every two weeks at a dose of about 6.5 mg / m2. In some embodiments, the TNBC is EphA2 -positive, i. e. is associated with EphA2 expression.

[0098] In some embodiments, the invention provides a method for TNBC in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient weekly at a dose of about 5 mg / m2. In some embodiments, the TNBC is EphA2 -positive, i. e. is associated with EphA2 expression.

[0099] In some embodiments, the methods of treating solid tumors of the invention provide methods for maintaining or reducing the volume of a solid tumor in a patient. In some embodiment, the cancer is TNBC. In some embodiments, the cancer is NSCLC. In some embodiments, the cancer is gastric or upper GI cancer. In some embodiments, the cancer is head and neck cancer. In some embodiments, the cancer is ovarian cancer.

[0100] In some embodiments, the invention provides a method for maintaining or reducing the volume of a solid tumor in a human patient, comprising administering BT5528 to the patient weekly at a dose of about 5 mg / m2. In some embodiments, the invention provides a method for maintaining or reducing the volume of a solid tumor in a human patient, comprising administering BT5528 to the patient every two weeks at a dose of about 6.5 mg / m2. In some embodiment, the cancer is TNBC. In some embodiments, the cancer is NSCLC. In some embodiments, the cancer is gastric or upper GI cancer. In some embodiments, the cancer is head and neck cancer. In some embodiments, the cancer is ovarian cancer.6. A Patient with a Solid Tumor

[0101] In some embodiments, the solid tumor or advanced malignancy is selected from lung cancer (e.g., NSCLC), ovarian cancer, fallopian tube cancer, breast cancer (e.g., TNBC), head and neck cancer, gastric / upper gastrointestinal (GI), pancreatic, urothelial cancer (e.g. bladder cancer,urethra cancer, urinary bladder cancer and urothelial carcinoma), bone cancer, rectal cancer, stomach cancer and squamous cancer of unknown origin. In some embodiments, the solid tumor or advanced malignancy associated with EphA2 -expression is an adenocarcinoma subtype of NSCLC (adeno-NSCLC).

[0102] In one embodiment, the solid tumor or advanced malignancy is lung cancer. In one embodiment, the lung cancer is NSCLC.

[0103] In one embodiment, the solid tumor or advanced malignancy is ovarian cancer. In one embodiment, the solid tumor or advanced malignancy is fallopian tube cancer.

[0104] In one embodiment, the solid tumor or advanced malignancy is breast cancer. In one embodiment, the breast cancer is triple-negative breast cancer.

[0105] In one embodiment, the solid tumor or advanced malignancy is head and neck cancer.

[0106] In one embodiment, the solid tumor or advanced malignancy is gastric cancer. In one embodiment, the solid tumor or advanced malignancy is upper gastrointestinal (GI) cancer.

[0107] In one embodiment, the solid tumor or malignancy is pancreatic cancer.

[0108] In one embodiment, the solid tumor or malignancy is urothelial cancer. In one embodiment, the urothelial cancer is bladder cancer. In one embodiment, the urothelial cancer is urethra cancer. In one embodiment, the urothelial cancer is urinary bladder cancer. In one embodiment, the urothelial cancer is urothelial carcinoma.

[0109] In one embodiment, the solid tumor or advanced malignancy is stomach cancer.

[0110] In one embodiment, the solid tumor or advanced malignancy is rectal cancer.

[0111] In one embodiment, the solid tumor or advanced malignancy is squamous cancer of unknown origin.

[0112] In some embodiments, the solid tumor or advanced malignancy is associated with EphA2 expression.

[0113] In some embodiments, BT5528 is administered to a patient at least 18 years-of-age. Put another way, in some embodiments, the patient is an adult patient.

[0114] In some embodiments, the patient is a patient having an Eastern Cooperative Oncology Group (ECOG) Performance Status score of 0 or 1. The ECOG Performance Status scores of 0 and 1 are described in Example 1.

[0115] In some embodiments, the patient is a patient having measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) vl.l.

[0116] In some embodiments, the patient is a patient having acceptable organ function. In some embodiments, a patient having acceptable organ function has laboratory data selected from the following:Renal function: creatinine clearance of >50 mL / min by the Cockcroft- Gault equation or as measured by 24-hour urine collection;Total bilirubin <1.5 x ULN (upper limit of normal);Serum albumin >2.5 g / dL;Aspartate aminotransferase (AST) <2.5 x ULN or <5 x ULN in the presence of liver metastases;Alanine aminotransferase (ALT) <2.5 x ULN or <5 x ULN in the presence of liver metastases; andInternational normal ratio (INR) <1.3 or < institutional ULN (anticoagulants not allowed).

[0117] In some embodiments, the patient is a patient having acceptable hematologic function. In some embodiments, a patient having acceptable hematologic function has laboratory data selected from the following:Hemoglobin >9 g / dL;Absolute neutrophil count (ANC) >1500 cells / mm3; andPlatelet count >75,000 cells / mm3.

[0118] In some embodiments, the patient has no red blood cell or platelet transfusions or growth factors within 4 weeks of the first dose of a pharmaceutical composition of the invention.

[0119] In some embodiments, the patient is a patient who is a woman of childbearing potential (WOCBP) that has a negative pregnancy test (negative serum test at screening and negative urine or serum test within 3 days prior to the first dose of BT5528).

[0120] In some embodiments, the patient has a metastatic recurrent histologically confirmed malignant solid tumor, and has exhausted all appropriate treatment options per local guidelines and must have failed at least one prior line of therapy with evidence of radiographic progression on the most recent line of therapy.

[0121] In some embodiments, the patient has received prior immunotherapy and has received the last dose at least 28 days prior to the first dose of BT5528.

[0122] In some embodiments, the patient has metastatic recurrent disease histologically confirmed to be non-small cell lung cancer (NSCLC), ovarian cancer, triple-negative breast cancer(TNBC), gastric / upper gastrointestinal (GI), cancer, head and neck cancer, or urothelial cancer are eligible; and has failed or is ineligible for all appropriate treatment options per local guidelines; and has evidence of radiographic progression on the most recent line of therapy.

[0123] In some embodiments, the patient has urothelial cancer and has previously received treatment with enfortumab vedotin (EV). In some embodiments, the patient showed disease progression within 6 months of EV treatment start.

[0124] In some embodiments, the patient has an adenocarcinoma subtype of NSCLC (adeno- NSCLC), and has exhausted all standard treatment options including progression on or after platinum-based chemotherapy, and / or has failed at least one prior line of therapy with evidence of radiographic progression on the most recent line of therapy. In some embodiments, a patient has EGFR, ALK, NTRK, ROS1 or other genomic tumor aberrations. In some embodiments, a patient has not received appropriate treatment for driver mutation disease. In some embodiments, a patient has not received immunotherapy at least 28 days prior to the first dose of a pharmaceutical composition of the invention. In some embodiments, the patient has not had a chemotherapy treatment within 14 days prior to first dose of a pharmaceutical composition of the invention. In some embodiments, a patient has not had an anticancer treatment within 28 days or 5 half-lives, whichever shorter, prior to first dose of a pharmaceutical composition of the invention. In some embodiments, a patient has prior toxicities which have resolved to grade 1 per Common Terminology Criteria for Adverse Events (CTCAE) v 5.0 (except alopecia which must be no greater than Grade 2).

[0125] In some embodiments, the patient has not had an experimental treatment within 4 weeks of first dose of a pharmaceutical composition of the invention.

[0126] In some embodiments, a patient does not have a current treatment with strong inhibitors or inducers of CYP3A4 or strong inhibitors of P-gp including herbal- or food-based.

[0127] In some embodiments, the patient does not have any sensitivity to any of the ingredients of a pharmaceutical composition of the invention, or to monomethyl auristatin E (MMAE).

[0128] In some embodiments, the patient does not have any significant medical condition, lifethreatening illness, active uncontrolled infection or organ system dysfunction (such as ascites, coagulopathy, encephalopathy).

[0129] In some embodiments, the patient has not had any major surgery (excluding placement of vascular access) within 4 weeks of first dose of a pharmaceutical composition of the invention.

[0130] In some embodiments, the patient has not received a live vaccine within 30 days of first dose of a pharmaceutical composition of the invention.

[0131] In some embodiments, the patient does not have uncontrolled, symptomatic brain metastases. In some embodiments, the patient has stable neurologic status following local therapy for at least 4 weeks without using steroids or on stable or decreasing dose of less than or equal to 10 mg daily prednisone or equivalent.

[0132] In some embodiments, the patient does not have untreated CNS metastases. In some embodiments, the patient has treated CNS metastases and a) CNS metastases have been clinically stable for at least 6 weeks prior to screening; b) If requiring steroid treatment for CNS metastases, the subject is on a stable or decreasing dose of <20 mg / day of prednisone or equivalent for at least 2 weeks; c) Baseline scans show no evidence of new or enlarged brain metastasis; d) Subject does not have leptomeningeal disease; and e) Subject must be without neurologic dysfunction that would confound the evaluation of neurologic and other AEs.

[0133] In some embodiments, the patient does not have uncontrolled hypertension (systolic blood pressure [BP] >139 mmHg; diastolic BP >89 mmHg) prior to first dose of a pharmaceutical composition of the invention. In some embodiments, a patient has hypertension which has been in stable control for at least 3 months prior to first dose of a pharmaceutical composition of the invention.

[0134] In some embodiments, the patient does not have uncontrolled hypertension (systolic blood pressure [BP] >160 mmHg; diastolic BP >100 mmHg that is not responsive to intervention) at screening or prior to first dose of a pharmaceutical composition of the invention. In some embodiments, a patient has hypertension which has been in stable control for at least 3 months prior to first dose of a pharmaceutical composition of the invention.

[0135] In some embodiments, the patient does not have a history of a cerebral vascular event (stroke or transient ischemic attack), unstable angina, myocardial infarction, congestive heart failure or symptoms of New York Heart Association Class III-IV documented within 6 months prior to first dose of a pharmaceutical composition of the invention.

[0136] In some embodiments, the patient does not have mean resting corrected QT interval (QTcF) >470 msec within 6 months prior to first dose of a pharmaceutical composition of the invention.

[0137] In some embodiments, the patient does not have, within 6 months prior to first dose of a pharmaceutical composition of the invention, any factors that increase the risk of QTc prolongation or risk of arrhythmic events such as heart failure, hypokalemia, congenital long QT syndrome, family history of long QT syndrome or unexplained sudden death under 40 years-of- age, or any concomitant medication known to prolong the QT interval.

[0138] In some embodiments, the patient does not have, within 6 months prior to first dose of a pharmaceutical composition of the invention, any clinically important abnormalities in rhythm, conduction, or morphology of resting electrocardiograms (ECGs), e.g., complete left bundle branch block, third degree heart block.

[0139] In some embodiments, the patient does not have human immunodeficiency virus (HIV) or acquired immune deficiency syndrome (AIDS).

[0140] In some embodiments, the patient has well controlled HIV and meets all the following criteria at inclusion: a. CD4+ counts > 350 cells / uL; b. HIV viral load < 400 copies / mL; c. Without a history of opportunistic infection within the last 12 months; d. On established ART for at least 4 weeks. Use of ART should be discussed with the Medical Monitor on a case-by-case basis.

[0141] In some embodiments, the patient does not have a positive hepatitis B surface antigen and / or anti-hepatitis B core antibody.

[0142] In some embodiments, the patient has a negative polymerase chain reaction (PCR) assay and has an appropriate antiviral therapy.

[0143] In some embodiments, the patient has an active hepatitis C infection with positive viral load if hepatitis C virus (HCV) antibody positive.

[0144] In some embodiments, the patient has been treated for hepatitis C infection and has sustained virologic response of >12 weeks.

[0145] In some embodiments, the patient does not have thromboembolic events and / or bleeding disorders within 3 months (e.g., deep vein thrombosis [DVT] or pulmonary embolism [PE]) prior to the first dose of a pharmaceutical composition of the invention.

[0146] In some embodiments, the patient does not have another malignancy within 3 years before the first dose of a pharmaceutical composition of the invention. In some embodiments, apatient does not have any residual disease from a previously diagnosed malignancy (excluding adequately treated with curative intent basal cell carcinoma, squamous cell of the skin, cervical intraepithelial neoplasia / cervical carcinoma in situ or melanoma in situ or ductal carcinoma in situ of the breast).

[0147] In some embodiments, the patient does not have systemic anti-infective treatment or fever within the last 14 days prior to first dose of a pharmaceutical composition of the invention.EXEMPLIFICATIONExample 1. Phase I / II Study of the Safety, Pharmacokinetics, and Preliminary Clinical Activity of BT5528 in Patients with Advanced Malignancies Associated with EphA2 Expression2.1 ObjectivesPrimary Objectives

[0148] The primary objectives of the escalation (Parts A-l and A-2) are:• To assess safety and tolerability of BT5528 administered weekly in patients with advanced solid tumor malignancies associated with EphA2-expression and / or specified tumors identified as positive for EphA2 tumor expression as a monotherapy (Part A-l) and in combination with nivolumab (Part A-2).To define MTD of BT5528, if observed, and determine one or more recommended phase 2 dose(s) (RP2D) as a monotherapy (Part A- 1) and in combination with nivolumab (Part A-2).

[0149] The primary objectives of the expansions (Part B) are:To assess the clinical activity of BT5528 as monotherapy in patients with solid tumors historically known for high expression of EphA2 (Cohort B-l : urothelial cancers, Cohort B-2: ovarian cancer, Cohort B-3: NSCLC, Cohort B-4: head and neck, Cohort B-5: TNBC, and Cohort B-6: gastric / upper GI) at one or more R2PD dosing regimens.Secondary Objectives

[0150] The secondary objectives of the escalation (Parts A-l and A-2) this study are:

[0151] To assess preliminary signals of anti-tumor activity achieved with BT5528 administration in patients with advanced solid tumor malignancies associated with EphA2- expression and / or specified tumors identified as positive for EphA2 tumor expression as amonotherapy (Parts A-l) and in combination with nivolumab (Parts A-2)The secondary objectives of the expansion (Part B) study are:• To assess safety and tolerability of BT5528 as monotherapy in patients with tumors historically known for high expression of EphA2To investigate whether tumor EphA2 expression levels are predictive of clinical activity with BT5528 monotherapy in patients with tumors historically known for high expression of EphA2

[0152] The secondary objectives of all parts of the study are:• To determine pharmacokinetic (PK) parameters of BT5528 and MMAE (as appropriate)• To determine incidence of anti-drug antibody (ADA)2.2. Study Design

[0153] This study is a Phase I / II, first-in-human, open-label dose-escalation study of BT5528 given as a single agent (Parts A-l and B) and in combination with nivolumab (Part A-2). There are two parts to this study: Part A, dose escalation and Part B, dose expansion.2.3. Study Drugs, Doses, and Modes of Administration:BT5528, in ascending doses, administered intravenously as infusion over Ih in Part A; as per RP2D in Part B. Nivolumab administered 480 mg intravenously every 4 weeks or 240 mg every 2 weeks in Part A2.4. Inclusion Criteria - All Patients:Patients must meet the following criteria to be included in the research study:Written informed consent, according to local guidelines, signed and dated by the patient or by a legal guardian prior to the performance of any study-specific procedures, sampling, or analysesIf a patient declines to participate in any voluntary component of the study (e.g., tumor biopsy), there will be no penalty or loss of benefit to the patient, and he / she will not be excluded from other aspects of the study. At least 18 years-of-age at the time of signature of the informed consent form Eastern Cooperative Oncology Group (ECOG) Performance Status score of 0 or 1Patients must have measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) v 1.1 Acceptable organ function, as evidenced by the following laboratory data:- Renal function, as follows: creatinine clearance of >50 mL / min by the Cockcroft-Gault equation or as measured by 24-hour urine collection.- Total bilirubin <1.5 x ULN (upper limit of normal)- Serum albumin >2.5 g / dL- Aspartate aminotransferase (AST) <2.5 x ULN or <5xULN in the presence of liver metastases- Alanine aminotransferase (ALT) <2.5 x ULN or <5 x ULN in the presence of liver metastases- International normal ratio (INR) <1.3 or < institutional ULN6. Acceptable hematologic function (no red blood cell or platelet transfusions or growth factors are allowed within 4 weeks of the first dose of BT5528):- Hemoglobin >9 g / dL- Absolute neutrophil count (ANC) >1500 cells / mm3- Platelet count >75,000 cells / mm37. Negative pregnancy test for women of childbearing potential (WOCBP) (negative serum test at screening and negative urine or serum test within 3 days prior to the first dose of BT5528). Male patients with female partners of childbearing potential and female patients of childbearing potential are required to follow highly effective contraception (oral and hormonal contraceptives allowed) at least as conservative as CTFG recommendations for less than 1% failure rate during their participation in the study and for 6 months following last dose of BT5528 (BT5528 IB) or 5 months following last dose of nivolumab (Nivolumab USPI or SmPC) for patients continuing treatment with nivolumab only after stopping treatment with BT5528. Male patients must also refrain from donating sperm during their participation in the study and for 5 or 6 months following last dose of either nivolumab or BT5528, respectively, and women must not breastfeed during that time or donate eggs.8. All patients must have tumor tissue (fresh or archived) available for analysis of EphA2 tumor expression and other biomarkers. In the absence of available tumor tissue, patients must be willing to undergo a biopsy to provide fresh tumor samples. Specifications on tissue requirements are provided in the laboratory manual.9. Life expectancy >12 weeks after the start of BT5528 treatment according to the Investigator’s judgment.10. Must be willing and able to comply with the protocol and study procedures.Additional Inclusion Criteria - Part A Only11. Patients with metastatic recurrent histologically confirmed malignant solid tumor who must have exhausted all appropriate treatment options per local guidelines and must have failed at least one prior line of therapy with evidence of radiographic progression on the most recent line of therapy. If applicable, for patients who received prior immunotherapy,the last dose must have been at least 28 days prior to the first dose of BT5528 study treatment.Patients with pancreatic cancer are allowable but are planned for less than 50% of total patients enrolled in each escalation cohort.The Sponsor or SRC may decide to require enrollment of specific tumor types or subtypes at any point during the escalation if it is felt necessary to enrich the evaluation of biomarkers, safety, or PK in a specific tumor type.12. Patients enrolling in Cohort A 1-8 or later for the Part A-l monotherapy or enrolling in Cohort A2-3 or later for the Part A-2 combination therapy must have tumor tissue (fresh or archived) available for central laboratory for prospective or retrospective analysis of EphA2 tumor expression but may be enrolled without prior confirmation of EphA2 expression. .Additional Inclusion Criteria - Part B monotherapy cohorts13. Patients with metastatic recurrent disease histologically confirmed to be non-small cell lung cancer (NSCLC), ovarian cancer, triple-negative breast cancer (TNBC), gastric / upper gastrointestinal (GI), cancer, head and neck cancer, or urothelial cancer are eligible; and must have failed or are ineligible for all appropriate treatment options per local guidelines; and must have evidence of radiographic progression on the most recent line of therapy.14. Patients with urothelial cancer who have previously received treatment with enfortumab vedotin (EV) are eligible to the study. Patients who received EV and showed disease progression within 6 months of treatment start are planned for less than 50% of total patients enrolled in the cohort.2.5. Exclusion Criteria - All Patients:

[0154] Patients who meet any of the following criteria will be excluded from study entry:1. Chemotherapy treatments within 14 days prior to first dose of study treatment. For other anticancer treatments, treatment within 28 days or 5 half-lives, whichever is shorter. For immunotherapy, including immune checkpoint inhibitors, treatment within 28 days prior to the first dose of study treatment.2. Experimental treatments within 4 weeks of first dose of BT5528 study treatment.3. Prior toxicities must have resolved to Grade 1 per Common Terminology Criteria for Adverse Events (CTCAE) v 5.0 (except alopecia which can be Grade 2).4. Current treatment with strong inhibitors or inducers of CYP3A4 or strong inhibitors of P- gp including herbal- or food-based.5. Known sensitivity to any of the ingredients of the investigational product or monomethyl auristatin E (MMAE).6. Significant medical condition, life-threatening illness, active uncontrolled infection or organ system dysfunction (such as ascites, coagulopathy, encephalopathy), or other reasons which, in the Investigator’s opinion, could compromise the patient’s safety, or interfere with or compromise the integrity of the study outcomes including consideration of gastrointestinal, skin and pulmonary co-morbidities and including review of screening chest CT to ensure no clinically significant co-morbidities.7. Major surgery (excluding placement of vascular access) within 4 weeks of first dose of BT5528 study treatment and must have recovered adequately prior to starting study therapy8. Receipt of live vaccine within 30 days of study treatment9. Untreated CNS metastases. Subjects with treated CNS metastases are permitted on study if all the following are true: a. CNS metastases have been clinically stable for at least 6 weeks prior to screening b. If requiring steroid treatment for CNS metastases, the subject is on a stable or decreasing dose of <20 mg / day of prednisone or equivalent for at least 2 weeks c. Baseline scans show no evidence of new or enlarged brain metastasisd. Subject does not have leptomeningeal disease e. Subject must be without neurologic dysfunction that would confound the evaluation of neurologic and other AEs. Uncontrolled hypertension (systolic BP >160 mmHg or diastolic BP >100 mm Hg that is not responsive to intervention) at screening or prior to initiation of study drug. History or current evidence of any condition, therapy or laboratory abnormality that might confound the results of the study, interfere with the patient’s participation, or is not in the best interest of the patient to participate in the opinion of the Investigator including but not limited to: a. Patients with history of a cerebral vascular event (stroke or transient ischemic attack), unstable angina, myocardial infarction, congestive heart failure or symptoms of New York Heart Association Class III-IV documented within 6 months prior to first dose of BT5528 or: i. Mean resting corrected QT interval (QTcF) >470 msec ii. Any factors that increase the risk of QTc prolongation or risk of arrhythmic events such as heart failure, hypokalemia, congenital long QT syndrome, family history of long QT syndrome or unexplained sudden death under 40 years-of-age, or any concomitant medication known to prolong the QT interval iii. Any clinically important abnormalities (as assessed by the Investigator) in rhythm, conduction, or morphology of resting electrocardiograms (ECGs), e.g., complete left bundle branch block, third degree heart block Known human immunodeficiency virus (HIV) or acquired immune deficiency syndrome (AIDS)Note: Well controlled HIV will be allowed if the patient meets all the following criteria at inclusion: a) CD4+ T-cell (CD4+) counts >350 cells / uL; b) HIV viral load <400 copies / mLc) Without a history of opportunistic infection within the last 12 months. d) On established antiretroviral therapy (ART) for at least 4 weeks. Use of antiretroviral therapy is permitted but should be discussed with the Medical Monitor on a case-by-case basis.13. Patients with a positive hepatitis B surface antigen and / or anti-hepatitis B core antibody. Patients with a negative polymerase chain reaction (PCR) assay are permitted with appropriate antiviral therapy14. Active hepatitis C infection with positive viral load if hepatitis C virus (HCV) antibody positive (if antibody is negative then viral load not applicable). Patients who have been treated for hepatitis C infection can be included if they have documented sustained virologic response of >12 weeks.15. Thromboembolic events and / or bleeding disorders within 3 months (e.g., deep vein thrombosis [DVT] or pulmonary embolism [PE]) prior to the first dose of BT5528 study treatment.16. Prior history of pneumonitis with presence of residual symptoms.17. History of another malignancy within 3 years before the first dose of BT5528, or any evidence of residual disease from a previously diagnosed malignancy (excluding adequately treated with curative intent basal cell carcinoma, squamous cell of the skin, cervical intraepithelial neoplasia / cervical carcinoma in situ or melanoma in situ or ductal carcinoma in situ of the breast).18. Systemic anti-infective treatment or fever within the last 14 days prior to first dose of BT5528 study treatment.19. Psychological, familial, sociological, or geographical conditions that do not permit compliance with the protocol and / or follow-up procedures outlined in the protocol.Additional Exclusion Criteria Part A-2 Nivolumab Combination Cohort20. Prior intolerance to immune checkpoint inhibitor21. Known hypersensitivity to checkpoint inhibitor therapy22. Prior organ transplant (including allogeneic)23. Diagnosis of clinically relevant immunodeficiency24. Active systemic infection requiring therapy25. More than 10 mg daily prednisone equivalent or other strong immunosuppressant26. History of autoimmune disease except alopecia or vitiligo2.6 Correlative Testing:

[0155] All patients will be required to provide archive tumor material or fresh tumor biopsy for assessment of expression levels of EphA2 and additional molecular genetic characterization (i.e. assessment of specific somatic mutations, etc.). This material should be provided as a tissue block or 10-15 paraffin-dipped unstained slides.

[0156] Part A-l monotherapy or enrolling in Cohort A2-3 or later for the Part A-2 combination therapy must have tumor tissue (fresh or archived) submitted to central laboratory for prospective or retrospective analysis of EphA2 tumor expression but may be enrolled without prior confirmation of EphA2 expression. The SRC may review the requirement for EphA2 expression prior to starting therapy where individual tumor types or subtypes have already demonstrated signs of efficacy.

[0157] For Part B (all expansion cohorts), analysis of EphA2 expression will be initially performed retrospectively and confirmation of EphA2 expression will not be required before study treatment. However, if the efficacy analysis performed on each individual indication or cohort indicates requirement for enrichment of patients with EphA2 expression in specific tumor indication cohort(s), confirmation of EphA2 expression before starting study treatment will be required for those cohort(s).

[0158] To investigate intratumoral PK / pharmacodynamic effects of BT5528, tumor biopsies will be collected after dosing per patient consent. Post-dose tumor biopsies are optional for all patients. The post-dose tumor biopsy will be collected from 4 hours of end of infusion (EOI) to 7 days after any BT5528 infusion within Cycle 1 or if not feasible then any later cycle is acceptable. Refer to the schedule of assessments (SoA) for further details.

[0159] Pre- and post-dose blood samples will also be collected to assess pharmacodynamic, response, and treatment resistance biomarkers, such as somatic mutations in circulating tumor DNA (ctDNA), ADA and pharmacogenomic analysis.2.7. Statistical Methodology:

[0160] Dose-escalation (applies separately to A-l and A-2): The actual number of dose levels to be explored in this study will depend on determination of the non-tolerable dose based on dose-limiting toxicities (DLTs). The MTD will be defined based on DLTs (see Section Error! Reference source not found.). Other safety data, as well as PK profiles observed during the conduct of the study and any trends for anti-tumor activity will be used to determine the RP2D which will be no greater than the MTD (or, in the absence of declaration of MTD, no greater than the maximum administrated dose [MAD], which is defined as the highest dose studied per escalation).

[0161] A 3+3 design will be used for the first two dose levels. At least 3 evaluable patients will be enrolled at each dose level and will be evaluated for 28 days before escalation to the next dose level can occur. After confirmation of tolerability in dose level 1 , dose escalation of no more than 100% will be allowed to dose level 2. Treatment cycles will occur consecutively as per the SoA. If one patient experiences a DLT an additional 3 patients will be treated with the same dose. Evaluation of a cohort of at least 3 patients completing 1 cycle of treatment (28 days) is required prior to proceeding to the next dose level. Additional details are found in Section 5.

[0162] Following evidence of tolerability at the first two dose levels, all subsequent dose interval escalations will be based on a type of continual reassessment method (CRM) using a two-parameter Bayesian logistic regression model (BLRM) and the escalation with overdose control (EWOC) principle that the next higher escalated dose level will include the highest posterior probability of a DLT occurring in the target interval (20%, 33%) among doses fulfilling the overdose criterion that there exist <25% likelihood of the dose level being found unsafe (DLT rate >33%). The BLRM will be applied to cumulative DLT / safety data and results will be made available to the SRC and, upon review of these data, the SRC will make a recommendation regarding the precise dose escalation.

[0163] Each cohort of each RP2D of Part B will employ a Simon 2-stage design where pO = 0.11 and pl = 0.30 with a 1-sided alpha of 0.05 and 80% power, where pO and pl are the null and alternative hypotheses for the overall response rate (ORR). If 3 or more patients show an OR among the first 14 patients recruited, then the cohort will be considered by Sponsor whether it is feasible to proceed into the second stage to enroll a further 26 patients; otherwise, the cohort will be stopped. An additional 26 patients will be enrolled in up to two Part B cohorts only.The efficacy outcomes from Part A of the study may be used to inform the enrichment of specific cohorts according to EphA2 status. For all cases of Part B of the study, efficacy will be determined based on OR.As a result of these changes the maximum number of patients recruited into the study is 288: 72 from Part A- 1 , 24 from Part A-2 and up to 192 patients in the Part B cohorts if clinical efficacy criteria as per the Simon’s Stage 2 analysis described above are met for all indications tested.For ORR and CBR, estimates and the associated 95% Cis (based on the Clopper-Pearson method) will be calculated. For PFS and OS, Kaplan-Meier curves will be generated, and the median time- to-event and the associated 95% Cis will be provided.Example 3. End of Phase I escalation top-line resultsBT5528 demonstrates advanced anti-tumor activity in advanced solid tumors with a promising overall safety / tolerability profile. The anti-tumor activity of BT5528 was tested in heavily pretreated cancer patients. A 67% ORR was observed in urothelial cancer patients with tumors associated with EphA2 expression (Figure 2). There is an emerging relationship between antitumor activity and EphA2 expression (Figure 3A). BT5528 was also shown to reduce tumor volume in a female patient with urothelial cancer who has received 4 prior lines of therapy (Figure 4). The emerging safety profile of BT5528 distinguishes it from other EphA2-targeted molecules:- No IMP-related clinical bleeding / coagulopathy- No evidence of IMP-related eye toxicity or clinically meaningful skin toxicity- No reports of ILD / pneumonitis in Part B- No significant liver toxicity- GI and hematological toxicity dose-dependent and manageable• Improvement in rates / severity of CINV with anti-emetic prophylaxis• Use of growth factors uncommon- BP / vital signs: no trends of concern- ECG: no trends of concern for QT issuesExample 4. Combined Phase I / II resultsSubsequent to the end of the Phase I dose escalation, Phase II data were also collected for heavily treated patients. These data confirm the anti-tumor and safety / tolerability signals identified in Example 3.Phase II data were combined with the existing Phase I data, including combined demographic data (Figure 7A) and solid tumor type breakdown (Figure 7B). The safety profile of BT5528 remains promising (Figure 8A - BT5528 safety summary; Figure 8B - most frequent treatment- related adverse events (>15%) - acceptable tolerability a RP2D; Figure 8C - treatment-related adverse events of interest - low incidence across all doses).Promising early response data are provided for urothelial cancer (Figure 9A - waterfall plot for tumor responses; Figure 9B - Spider plot for tumor response). The urothelial cancer patientswere heavily pre-treated, and the prior treatment history of the seven responders with urothelial cancer is as follows:Prior therapies of the seven UC responders:All patients had received prior immunotherapy. Two patients had received ADCs, of which one had received enfortumab vedotin (EV)Efficacy evaluable set is used which is defined as all enrolled patients with measurable disease at baseline who received at least one dose of BT5528 and had at least one adequate post-baseline disease assessment. Four patients were excluded due to no post-baseline assessment. A fifth patient was excluded from the waterfall plot as target lesion data was non-evaluable in the single post-baseline assessment.Overall, of the 18 patients, seven patients (six confirmed) showed a partial response and three patients (one confirmed) had stable disease beyond four months. Eight patients showed progressive disease. The clinical benefit rate (CBR) (confirmed partial response or stabledisease) and objective response rate (ORR) (partial response) were 39%. Of these, for the 16 patients administered 6.5 mg / m2BT5528 once every two weeks, five patients (four confirmed) showed a partial response and three patients (one confirmed) had stable disease beyond four months. The CBR and ORR were 31%. When the B-l expansion cohort (6.5 mg / m2Q2W with prophylactic anti-emetics) are separated, an ORR of 45.5% was observed among efficacy evaluable patients (n=l 1).Tumor shrinkage (including formal responses) were also seen in patients with other tumors, including ovarian cancer (Figure 9C-D), head and neck cancer (Figure 9E) and gastric / upper GI cancer (Figure 9F). Stable disease was also seen in patients with NSCLC (Figure 9G) and TNBC (Figure 9H). The response data for urothelial cancer and ovarian cancer are summarized (Figure 91).Example 5. BT5528 dosing modelling.Simulations for MMAE PK profile were carried out for a 5 mg / m2weekly dose of BT5528. This was predicted to offer a 54% higher dose / exposure of MMAE compared to a 6.5 mg / m2dose administered every two weeks, simulated in a typical subject with BSA of 1.8 m2using the PK model as of the date of the data cut (Figure 10A-B). An exposure-safety relationship was observed for Grade >3 TRAE (Figure 11 A), dose modification due to treatment-related adverse events (AE) (Figure 1 IB) and Grade >3 neutropenia (Figure 11C) with MMAE Cmax. Exposureresponse analysis was based on available data as of the data cut. Exposure-response relationships were examined using logistic regression. Simulated adverse event rates were from logistic regression driven by MMAE Cycle 1 Cmax in a virtual patient population. Together, these data suggest that a 5 mg / m2weekly dosing regimen may be a promising dose for further investigational studies, and may offer greater efficacy whilst retaining an acceptable safety / tolerability profile.Example 6: BT5528 dose optimizationIn view of the dosing modelling work described herein, a further dose optimization study was conducted to investigate the safety / tolerability and efficacy of a 5 mg / m2weekly dose of BT5528. Patients in this cohort received prophylactic anti-emetics.Interim safety / tolerability data are shown in Figure 12A-C. The safety analysis population includes patients who received at least one dose of BT5528. These data suggest that BT5528 is well tolerated at the 5 mg / m2QW dose, and that the 5 mg / m2 QW dose shows comparable tolerability to the 6.5 mg / m2Q2W dose. Figure 12C includes a summary of related TEAEs for BT5528 at the 5 mg / m2QW dose and 6.5 mg / m2Q2W dose, with TEAEs for the 6.5 mg / m2reported as of a more recent data cut than in earlier Examples.Efficacy of the 5 mg / m2QW dose was also investigated. The efficacy evaluable population includes all patients who received at least one dose of BT5528 and had at least one post-baseline assessment. For ORR (CR+PR) and CBR (CR+PR+SD>4 months from C1D1), patients without a post-baseline tumor assessment will be classed as not evaluable (NE) and considered as nonresponders.As of the date of the data cut, 3 patients (27.3%) showed a partial response and 4 patients (36.4%) had stable disease beyond four months (Figure 13 A). Patient responses are shown graphically as a spider plot (Figure 13B) and as a waterfall plot (Figure 13C) The study is ongoing as of the date of the data cut: 3 patients are still receiving BT5528, including two patients with unconfirmed partial response and one patient with stable disease.On this basis, the 5 mg / m2QW dosage regime shows acceptable safety and tolerability, as well as signs of efficacy in urothelial cancer patients.

Claims

CLAIMS1. A method for treating a human patient, comprising administering to the patient BT5528 or a pharmaceutical composition comprising BT5528.

2. A method for treating a solid tumor in a human patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528.

3. A method for maintaining or reducing the volume of a solid tumor in a patient, comprising administering BT5528 or a pharmaceutical composition comprising BT5528.

4. The method of claim 2 or 3, wherein the solid tumor is an advanced malignancy.

5. The method of any one of claims 2 to 4 wherein the solid tumor or advanced malignancy is associated with EphA2 expression in a human patient6. The method of any one of claims 1 to 5, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient every two weeks at a dose of about 4-8 mg / m2, optionally a dose of about 5-7 mg / m2, optionally a dose of about 6.5 mg / m2.

7. The method of any one of claims 1 to 5, comprising administering BT5528 or a pharmaceutical composition comprising BT5528 to the patient weekly at a dose of about 3-7 mg / m2, optionally a dose of about 4-6 mg / m2, optionally a dose of about 5 mg / m2.

8. The method of any of claims 2-7, wherein the solid tumor or advanced malignancy is selected from the group consisting of lung cancer (e.g., NSCLC), ovarian cancer, fallopian tube cancer, breast cancer (e.g., TNBC), head and neck cancer, gastric / upper gastrointestinal (GI), pancreatic, urothelial cancer (e.g. bladder cancer, urethra cancer, urinary bladder cancer and urothelial carcinoma), bone cancer, rectal cancer, stomach cancer and squamous cancer of unknown origin.

9. The method of any one of claims 1 to 8, further comprising administering an anti-PD-1 antibody or an anti-PD-L 1 antibody to the patient, optionally wherein the anti-PD- 1 antibody is nivolumab.

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