Methods of treating cancer with oral dosage forms of estrogen receptor-alpha inhibitors

Abstract

The present invention relates to pharmaceutical compositions comprising an inhibitor of human ERa, and methods of cancer treatment using ERa inhibitors. In particular, described herein are doses of H3B-6545 with defined pharmacokinetic (PK) profiles that allow for the effective and safe administration of the inhibitor to human subjects in need thereof.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 852,751, filed May 24, 2019, and U.S. Provisional Patent Application No. 62 / 853,498, filed May 28, 2019. The above applications are incorporated by reference into the present application as if fully set out herein. BACKGROUND

[0003] Altered estrogen receptor (hereinafter referred to as ER) signaling is known to play a critical role in the development of multiple types of breast cancer. Activation of ER signaling is typically dependent on the expression and ability of endogenous steroid hormones, such as estradiol, to permeate into the cell and interact with intracellular ER. ER signaling, once activated, can promote a variety of cellular processes, such as proliferation, angiogenesis, metabolism, and cell survival (Toss A. et al., 2017, Int. J. Mol. Sci., 18(1): 85). During tumorigenesis, mutations develop in different ERs, which confer the ability to the cancer cells to activate the ER signaling pathway in a ligand-independent manner. ERa is one particular ER known to be involved in breast cancer tumorigenesis, which is a hormone-regulated transcription factor present in 50% of all breast cancers (Lumachi F., Curr. Med Chem. 2013; 20: 596-604).

[0004] The hormone-regulated transcription factor estrogen receptor alpha (ERa, ESR1) is expressed in about 70% of breast cancers. Lumachi F., Curr. Med. Chem. 2013; 20: 596-604. Multiple ERa-directed therapies have been developed. Resistance to ERa antagonists is common in the clinic and involves several mechanisms. As one mechanism, ERa mutations occur in 20-40% of endocrine therapy-resistant metastases. Li S, Cell Rep. 2013; 4: 1116-1130; Robinson DR, Nat Genet. 2013; 45: 1446-1451; Toy W, Nat Genet. 2013; 45: 1439-1445; Chandarlapaty S, JAMA Oncol. 2016; 2: 1310-1315; Spoerke JM, Nat Commun. 2016; 7: 11579. Mutations in ERa lead to ligand-independent activation of the ERa pathway.

[0005] Endocrine therapy is a frontline treatment method for treating or curing breast cancer. Endocrine therapy is a therapy that involves promoting or inhibiting the expression or function of hormones in the body to treat a particular disease. Endocrine therapy targeting ERa has shown to be ineffective in the long-term treatment method of breast cancer, the reason for which is that 20 to 40% of all ERa-expressing breast cancers acquire mutations in ERa that render the receptor unresponsive to conventional endocrine therapy after prolonged endocrine therapy (Robinson, D. R., Nat. Genet. 2013; 45: 1446-1451). Therefore, in the field of chemotherapy, there is a need to develop new treatment methods capable of effectively targeting the mutant isoforms of ERa that confer endocrine therapy resistance to cancer.

[0006] In the process of seeking to develop new treatment methods for endocrine therapy-resistant breast cancer, a new class of ERa inhibitors has been discovered, which are referred to as selective estrogen receptor covalent antagonists (hereinafter SERCas). SERCas inactivate ER signaling by targeting cysteine residues on ER that are not present in other nuclear hormone receptors (Puyang, X., Cancer Discov. 2018, 8(9): 1176-1193). One of the SERCas that emerged during this period is (E)-N,N-dimethyl-4-[2-[5-[(Z)-4,4,4-trifluoro-1-(3-fluoro-1H-indazol-5-yl)-2- phenylbut-1-enyl]pyridin-2-yl]oxyethylamino]but-2-enamide, which is shown in the following Formula I:

[0007]

[0008] The free base form of (E)-N,N-dimethyl-4-[2-[5-[(Z)-4,4,4-trifluoro-1-(3-fluoro-1H- indazol-5-yl)-2-phenylbut-1-enyl]pyridin-2-yl]oxyethylamino]but-2-enamide is sometimes referred to as H3B-6545. H3B-6545 is a covalent small molecule inhibitor that inactivates both wild-type ERa (ERa-WT) and mutant ERa (ERa-mut) without degrading the receptor. H3B-6545 is able to interact with the Cys530 residue of ERa, thereby causing the receptor to adopt a unique conformation that inhibits the ability of the receptor to promote transduction of ligand-independent ERa signaling (Puyang, X., Cancer Discov. 2018, 8(9): 1176-1193). H3B-6545 has been shown to be able to elicit potent chemo therapeutic properties in various breast cancer cell lines and patient-derived xenograft models in nude mice (Smith, P. G. et al., Cancer Res. 2017).

[0009] While H3B-6545 has shown efficacy in in vitro and in vivo models, there remains a need to determine the manner in which to administer H3B-6545 to human breast cancer patients in need of treatment. Thus, there is a need to design formulations and dosage regimens of H3B-6545 such that the inhibitor is more effectively and safely administered to human subjects in need thereof. The pharmacokinetic (hereinafter PK) results and PK profiles described below demonstrate their general use in methods of treatment of human breast cancer. SUMMARY

[0011] Some embodiments can provide, for example, an oral dosage form comprising a compound of Formula I or a pharmaceutically acceptable salt thereof and at least one pharmaceutically acceptable excipient, wherein the Formula I is (E)-N,N-dimethyl-4-[2-[5-[(Z)-4,4,4-trifluoro-1-(3-fluoro-1H-indazol-5-yl)-2- phenylbut-1-enyl]pyridin-2-yl]oxyethylamino]but-2-enamide; wherein the oral dosage form is formulated to achieve a mean C max of about 1 ng / mL to about 4 ng / mL in a human subject when orally administered once daily. max In some embodiments, the mean C max of about 2 ng / mL to about 4 ng / mL for each mg of Formula I in the dose. In some embodiments, the mean C max of about 3 ng / mL to about 4 ng / mL for each mg of Formula I in the dose. In some embodiments, the mean C max of about 3 ng / mL to about 4 ng / mL for each mg of Formula I in the dose.

[0012] In other embodiments, the dosage form is formulated to achieve a mean t max of the mean C max of about 3 hours to about 7 hours. In other embodiments, the dosage form is formulated to achieve a mean t max of the mean C max of about 3.5 hours to about 4.5 hours. In other embodiments, the dosage form is formulated to achieve a mean t max of the mean C max of about 5.5 hours to about 6.5 hours. In other embodiments, the dosage form is formulated to achieve a mean t max of the mean C max .

[0013] In some embodiments, as reported previously, the dosage form comprises a total equivalent amount of about 100 mg to about 600 mg of Formula I. In some embodiments, the dosage form comprises a total equivalent amount of about 450 mg of Formula I.

[0014] Other embodiments provide an oral dosage form comprising a compound of Formula I, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient, wherein the Formula I is (E)-N,N-dimethyl-4-[2-[5-[(Z)-4,4,4-trifluoro-1-(3-fluoro-1H-indazol-5-yl)-2- phenylbut-1-enyl]pyridin-2-yl]oxyethylamino]but-2-enamide, wherein the oral dosage form is formulated to achieve a mean AUCo-24 of about 16 h*ng / mL to about 44 h*ng / mL per mg of Formula I in the dose when orally administered once daily to human subjects. In some embodiments, the mean AUCo-24 is about 27 h*ng / mL to about 44 h*ng / mL per mg of Formula I in the dose. In some embodiments, the mean AUCo-24 is in the range of 80% to 125% of 30 h*ng / mL to 80% to 125% of 44 h*ng / mL per mg of Formula I in the dose. In some embodiments, the dosage form comprises a total equivalent amount of about 100 mg to about 600 mg of Formula I. In some embodiments, the dosage form comprises a total equivalent amount of about 450 mg of Formula I.

[0015] Other embodiments provide an oral dosage form comprising a compound of Formula I, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient, wherein the Formula I is (E)-N,N-dimethyl-4-[2-[5-[(Z)-4,4,4-trifluoro-1-(3-fluoro-1H-indazol-5-yl)-2- phenylbut-1-enyl]pyridin-2-yl]oxyethylamino]but-2-enamide, wherein the oral dosage form is formulated to achieve a mean t 1 / 2 of about 8 hours to about 22 hours of the Formula I of the dosage form when orally administered once daily to human subjects. In other embodiments, the mean t 1 / 2 of about 8 hours to about 12 hours. In other embodiments, the mean t 1 / 2 of about 9 hours to about 11 hours. In some embodiments, the dosage form comprises a total equivalent amount of about 100 mg to about 600 mg of Formula I. In some embodiments, the dosage form comprises a total equivalent amount of about 450 mg of Formula I.

[0016] Other embodiments provide an oral dosage form comprising a compound of Formula I, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient, wherein the compound of Formula I is (E)-N,N-dimethyl-4-[2-[5-[(Z)-4,4,4-trifluoro-1-(3-fluoro-1H-indazol-5-yl)-2- phenylbut-1-enyl]pyridin-2-yl]oxyethylamino]but-2-enamide, wherein the oral dosage form is formulated to achieve a mean AUC of about 21 h*ng / mL to about 67 h*ng / mL per mg of Formula I in the dose when orally administered once daily to a human subject 0-inf In some embodiments, the mean AUC per mg of Formula I in the dose is about 29 h*ng / mL to about 67 h*ng / mL. 0-inf In some embodiments, the mean AUC per mg of Formula I in the dose is about 29 h*ng / mL to about 67 h*ng / mL. 0-inf In some embodiments, the mean AUC per mg of Formula I in the dose is about 29 h*ng / mL to about 67 h*ng / mL.

[0017] Still other embodiments can include the dosage forms described herein having means to achieve the pharmacokinetic values described herein.

[0018] Another embodiment provides an oral dosage form comprising a compound of Formula I, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient, wherein the compound of Formula I is (E)-N,N-dimethyl-4-[2-[5-[(Z)-4,4,4-trifluoro-1-(3-fluoro-1H-indazol-5-yl)-2- phenylbut-1-enyl]pyridin-2-yl]oxyethylamino]but-2-enamide, wherein the oral dosage form is formulated to achieve a mean AUC of about 16 h*ng / mL to about 41 h*ng / mL per mg of Formula I in the dose when orally administered once daily to a human subject 0-t In another embodiment, the mean AUC per mg of Formula I in the dose is about 16 h*ng / mL to about 41 h*ng / mL. 0-t In another embodiment, the mean AUC per mg of Formula I in the dose is about 16 h*ng / mL to about 41 h*ng / mL.

[0019] In other embodiments, the dosage form as previously reported can be a capsule comprising an inner phase comprising Formula I or a pharmaceutically acceptable salt, lactose monohydrate, low-substituted hydroxypropyl cellulose, microcrystalline cellulose, hydroxypropyl cellulose, colloidal anhydrous silica, and magnesium stearate; and an outer phase comprising magnesium stearate. In some embodiments, the capsule is a hypromellose capsule. In some embodiments, the capsule comprises a mono-HCl salt form of Formula I.

[0020] In some embodiments as previously reported, the oral dosage form is a tablet comprising an inner phase comprising Formula I or a pharmaceutically acceptable salt, lactose monohydrate, low-substituted hydroxypropyl cellulose, hydroxypropyl methylcellulose, colloidal silica, and purified water; an outer phase comprising microcrystalline cellulose and magnesium stearate; and a film coating comprising hydroxypropyl methylcellulose, talc, titanium dioxide, propylene glycol, iron oxide, and purified water. In other embodiments, the tablet comprises a mono-HCl salt form of Formula I.

[0021] Other embodiments provide a method of treating cancer in a human subject, the method comprising administering to the subject an oral dosage form comprising a therapeutically effective amount of a compound of Formula I or a pharmaceutically acceptable salt thereof, at least one pharmaceutically acceptable excipient, wherein the Formula I is (E)-N,N-dimethyl-4-[2-[5-[(Z)-4,4,4-trifluoro-1-(3-fluoro-1H-indazol-5-yl)-2- phenylbut-1-enyl]pyridin-2-yl]oxyethylamino]but-2-enamide, wherein the therapeutically effective amount is a single daily dose in a range of about 100 mg to 600 mg, wherein the oral dosage form has a mean Cmax of about 1 ng / mL to about 4 ng / mL in the subject’s plasma for each mg of Formula I in the dose, wherein the oral dosage form has a mean t max In some embodiments, the mean Cmax is about 2 ng / mL to about 4 ng / mL for each mg of Formula I in the dose. max In some embodiments, the mean Cmax is about 2 ng / mL to about 4 ng / mL for each mg of Formula I in the dose. max In some embodiments, the mean Cmax is about 2 ng / mL to about 4 ng / mL for each mg of Formula I in the dose. max In some embodiments, the mean Cmax is about 2 ng / mL to about 4 ng / mL for each mg of Formula I in the dose. max In some embodiments, the oral dosage form has a mean t max In some embodiments, the oral dosage form has a mean t max In some embodiments, the oral dosage form has a mean tmax In some embodiments, the dosage form has a mean Cmaxof the Formula I of about 3.5 hours to about 4.5 hours. max In some embodiments, the mean t max In some embodiments, the dosage form has a mean Cmaxof the Formula I of about 5.5 hours to about 6.5 hours. max In some embodiments, the mean t max .

[0022] Other embodiments provide a method of treating cancer in a human subject, the method comprising administering to the subject an oral dosage form comprising a therapeutically effective amount of a compound of Formula I or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient, wherein the compound of Formula I is (E)-N,N-dimethyl-4-[2-[5-[(Z)-4,4,4-trifluoro-1-(3-fluoro-1H-indazol-5-yl)-2- phenylbut-1-enyl]pyridin-2-yl]oxyethylamino]but-2-enamide, and wherein the oral dosage form has a mean AUCo-24 of about 16 h*ng / mL to about 44 h*ng / mL per mg of Formula I in the dose. 0-24 In other embodiments, the mean AUCo-24 is about 27 h*ng / mL to about 44 h*ng / mL per mg of Formula I in the dose. 0-24 In other embodiments, the mean AUCo-24 is in the range of 80% to 125% of 30 h*ng / mL to 80% to 125% of 44 h*ng / mL per mg of Formula I in the dose.

[0023] Other embodiments provide a method of treating cancer in a human subject, the method comprising administering to the subject an oral dosage form comprising a therapeutically effective amount of a compound of Formula I or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient, wherein the compound of Formula I is (E)-N,N-dimethyl-4-[2-[5-[(Z)-4,4,4-trifluoro-1-(3-fluoro-1H-indazol-5-yl)-2- phenylbut-1-enyl]pyridin-2-yl]oxyethylamino]but-2-enamide, and wherein the oral dosage form has a mean t 1 / 2 In some embodiments, the mean t 1 / 2 is about 8 hours to about 12 hours. In some embodiments, the mean t 1 / 2 is about 9 hours to about 11 hours.

[0024] Other embodiments provide methods of treating cancer in a human subject, the method comprising administering to the subject an oral dosage form comprising a therapeutically effective amount of a compound of Formula I or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient, wherein the compound of Formula I is (E)-N,N-dimethyl-4-[2-[5-[(Z)-4,4,4-trifluoro-1-(3-fluoro-1H-indazol-5-yl)-2- phenylbut-1-enyl]pyridin-2-yl]oxyethylamino]but-2-enamide, wherein the oral dosage form has a mean AUC of about 21 h*ng / mL to about 67 h*ng / mL for each mg of Formula I in the dose 0-inf In some embodiments, the mean AUC for each mg of Formula I in the dose is about 29 h*ng / mL to about 67 h*ng / mL. 0-inf In some embodiments, the mean AUC for each mg of Formula I in the dose is about 29 h*ng / mL to about 67 h*ng / mL. 0-inf In some embodiments, the mean AUC for each mg of Formula I in the dose is about 29 h*ng / mL to about 67 h*ng / mL.

[0025] Other embodiments provide methods of treating cancer in a human subject, the method comprising administering to the subject an oral dosage form comprising a therapeutically effective amount of a compound of Formula I or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient, wherein the compound of Formula I is (E)-N,N-dimethyl-4-[2-[5-[(Z)-4,4,4-trifluoro-1-(3-fluoro-1H-indazol-5-yl)-2- phenylbut-1-enyl]pyridin-2-yl]oxyethylamino]but-2-enamide, wherein the oral dosage form has a mean AUC of about 16 h*ng / mL to about 41 h*ng / mL for each mg of Formula I in the dose 0-t In some embodiments, the mean AUC for each mg of Formula I in the dose is about 29 h*ng / mL to about 67 h*ng / mL. 0-t In some embodiments, the mean AUC for each mg of Formula I in the dose is about 29 h*ng / mL to about 67 h*ng / mL.

[0026] In some embodiments of the methods reported herein, the dosage form comprises a total equivalent amount of Formula I of about 100 mg to about 600 mg. In other embodiments, the dosage form comprises a total equivalent amount of Formula I of about 200 mg to about 600 mg. In other embodiments, the dosage form comprises a total equivalent amount of Formula I of about 300 mg to about 600 mg. In other embodiments, the dosage form comprises a total equivalent amount of Formula I of about 450 mg.

[0027] In some embodiments of the methods reported herein, the oral dosage form is a capsule comprising an inner phase comprising a compound of Formula I or a pharmaceutically acceptable salt, lactose monohydrate, low-substituted hydroxypropylcellulose, microcrystalline cellulose, hydroxypropylcellulose, colloidal anhydrous silica, and magnesium stearate; and an outer phase comprising magnesium stearate. In some embodiments, the capsule is a hypromellose capsule. In some embodiments, the capsule comprises a mono-HCl salt form of Formula I.

[0028] In some embodiments reported herein, the oral dosage form is a tablet comprising an inner phase comprising a compound of Formula I or a pharmaceutically acceptable salt, lactose monohydrate, low-substituted hydroxypropylcellulose, hydroxypropylmethylcellulose, colloidal silica, and purified water; an outer phase comprising microcrystalline cellulose and magnesium stearate; and a film coating comprising hydroxypropylmethylcellulose, talc, titanium dioxide, propylene glycol, iron oxide, and purified water. In some embodiments, the tablet comprises a mono-HCl salt form of Formula I.

[0029] In some embodiments reported herein, the cancer is breast cancer. In some embodiments, the breast cancer is ERa-positive breast cancer. In some embodiments, the breast cancer expresses wild-type ERa. In some embodiments, the breast cancer expresses mutant ERa.

[0030] In some embodiments reported herein, the oral dosage form is administered once daily. In some embodiments, the oral dosage form is administered to a human in a fasted state. In some embodiments, the oral dosage form is administered to a human in a fed state.

[0031] Embodiments provide methods of treating a patient with a compound H3B-6545 or a pharmaceutically acceptable salt thereof:

[0032]

[0033] The methods comprise identifying whether a reduction in one or more mutant allele frequencies is observed in the blood of the patient, selecting the patient in which the reduction is observed, and administering to the selected patient a therapeutically effective amount of H3B-6545 or a pharmaceutically acceptable salt thereof. A mutant allele frequency is the relative frequency of a mutant allele (variant of a gene) at a particular locus in a population, and is expressed as a fraction or percentage.

[0034] H3B-6545 is reported in U.S. Patent No. 9,796,683 B2, which is incorporated herein by reference.

[0035] In some embodiments reported herein, the pharmaceutically acceptable salt of H3B-6545 is a HC1 salt of H3B-6545.

[0036] In some embodiments, a decrease in mutant allele frequency is observed in one or more alleles selected from the group consisting of PIK3CA, ESR1, TSC1, TP53, FGFR1, CCND1, ARID1A, POLE, FGF19, MET, NOTCH3, FGF3, AKT1, KRAS, MYC, ERBB2, ERBB3, FGFR3, PMS2, PTEN, RB1, BRAF, MDM2, ATR, ATRX, BRCA2, SETD2, ATM, FANCA, JAK2, NF1, SLX4, and SMAD4.

[0037] In another embodiment, a decrease in mutant allele frequency is observed in AKT1. In another embodiment, the AKT1 mutation position that results in the observed decrease in mutant allele frequency is E17. In another embodiment, the AKT1 mutation that results in the observed decrease in mutant allele frequency is E17K.

[0038] In another embodiment, a decrease in mutant allele frequency is observed in ESR1. In another other embodiment, the ESR1 mutation position that results in the observed decrease in mutant allele frequency is selected from one or more members of the group consisting of E380, D538, L536, S463, and Y537. In another embodiment, the ESR1 mutation that results in the observed decrease in mutant allele frequency is selected from one or more members of the group consisting of E380Q, D538G, L536H, L536P, L536R, S463P, Y537C, Y537N, and Y537S. In another embodiment, the ESR1 mutation that results in the observed decrease in mutant allele frequency is S463P. In another embodiment, the ESR1 mutation that results in the observed decrease in mutant allele frequency is Y537N.

[0039] In another embodiment, a decrease in mutant allele frequency is observed in PIK3CA. In another embodiment, the PIK3CA mutation position that results in the observed decrease in mutant allele frequency is selected from one or more members of the group consisting of E542, E545, and H1047. In another embodiment, the PIK3CA mutation that results in the observed decrease in mutant allele frequency is selected from one or more members of the group consisting of E542K, E545K, H1047L, and H1047R.

[0040] Other embodiments can provide methods of discontinuing treatment with a compound H3B-6545, or a pharmaceutically acceptable salt thereof, from a patient who has undergone treatment with a compound H3B-6545, or a pharmaceutically acceptable salt thereof:

[0041]

[0042] The method comprises identifying whether an increase in mutant allele frequency is observed in the patient's blood, and if the increase is observed, discontinuing treatment of the patient.

[0043] In some embodiments, the increase in mutant allele frequency is observed in one or more alleles selected from the group consisting of PIK3CA, ESR1, TSC1, TP53, FGFR1, CCND1, ARID1A, POLE, FGF19, MET, NOTCH3, FGF3, AKT1, KRAS, MYC, ERBB2, ERBB3, FGFR3, PMS2, PTEN, RB1, BRAF, MDM2, ATR, ATRX, BRCA2, SETD2, ATM, FANCA, JAK2, NF1, SLX4, and SMAD4.

[0044] In some embodiments, the increase in mutant allele frequency is observed in ESR1. In yet other embodiments, the ESR1 mutation position resulting in the observed increase in mutant allele frequency is selected from one or more members of the group consisting of E380, D538, L536, S463, and Y537. In other embodiments, the ESR1 mutation resulting in the observed increase in mutant allele frequency is selected from at least one member of the group consisting of E380Q, D538G, L536H, L536P, L536R, S463P, Y537C, Y537N, and Y537S.

[0045] In other embodiments, the increase in mutant allele frequency is observed in PIK3CA. In yet other embodiments, the PIK3CA mutation position resulting in the observed increase in mutant allele frequency is selected from the group consisting of E542, E545, and H1047. In yet other embodiments, the PIK3CA mutation resulting in the observed increase in mutant allele frequency is selected from the group consisting of E542K, E545K, H1047L, and H1047R. In other embodiments, the PIK3CA mutation is E545K.

[0046] In another embodiment, the increase in mutant allele frequency is observed in AKT1. In another embodiment, the AKT1 mutation position resulting in the observed increase in mutant allele frequency is E17. In other embodiments, the AKT1 mutation resulting in the observed increase in mutant allele frequency is E17K.

[0047] In still other embodiments, the step of identifying is performed after the patient has received at least one treatment with Compound H3B-6545, or a pharmaceutically acceptable salt thereof:

[0048]

[0049] In other embodiments, the patient has breast cancer. In still other embodiments, the breast cancer is an estrogen receptor alpha (ERa) positive breast cancer. In yet other embodiments, the ERa has a mutation.

[0050] In still other embodiments, an increase in mutant allele frequency is observed in circulating tumor DNA. In other embodiments, a decrease in mutant allele frequency is observed in circulating tumor DNA.

[0051] Documents reported herein are incorporated by reference herein. In the event of a conflict between the documents reported herein and the text, the text controls. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 A plot showing the mean plasma concentration of H3B-6545 over time in Example 3 (Cycle 1, Day 1) is shown. Preliminary PK analysis indicates that H3B-6545 exhibits approximately dose proportional increases for plasma exposures from 100 mg to 600 mg. max and half-life appear to be independent of dose and time.

[0053] Figure 2 A plot showing tumor response and duration of H3B-6545 treatment reported in Example 3 is shown. Partial response, stable response, progressive disease, and not evaluable are shown in each tumor assessment. Arrows indicate treatment ongoing at time of data cutoff.

[0054] Figure 3 A plot showing percent change in sum of diameters of target lesions reported in Example 3 is shown.

[0055] Figure 4 A summary of liquid biopsy and tissue biopsy sample sets is shown.

[0056] Figure 5 A Figure 5 E A plot showing the baseline genomic profile of patients in Example 7 is shown. Figure 5 A to 5E A plot showing the BEAMing assay. A: Baseline ESR1 and PIK3CA mutation status of patients; B and C: Clonality of ESR1 and PIK3CA mutations; D and E: Amino acid distribution of PIK3CA and ESR1 mutations. Figure 5FA waterfall plot of mutations found in baseline tissue biopsies determined by the Oncomine Comprehensive Panel is shown.

[0057] Figure 6A and Figure 6B Consistency of mutations found in tissue and liquid biopsies of Example 7 is shown. Figure 6A Distribution and consistency of tissue and liquid biopsy mutations are shown. Figure 6B Is a summary table of tissue and liquid biopsy mutation consistency.

[0058] Figures 7A-7C ctDNA kinetics associated with overall best response to H3B-6545 are shown. AF = allele frequency, C = cycle, D = days, PD = progressive disease, PR = partial response, SD = stable disease. Dotted lines represent ddPCR assay LOD. Figure 7A The ratio of AF baseline / C2D1 is shown for each patient, individually colored. One patient can have multiple mutations. Figure 7B and Figure 7C Examples of ctDNA kinetics in patients with progressive disease (B) versus partial response (C) are shown. DETAILED DESCRIPTION

[0060] Definitions

[0061] As used herein, the use of the articles "a" and "an" are to be construed as meaning "one or more" unless otherwise indicated or clearly contradicted by context. For example, the term "disintegrant" means one or more disintegrants included in or suitable for use in the formulations described herein. Similarly, the term "therapeutic amount" means one or more therapeutic amounts included in or suitable for use in the dosage forms.

[0062] The terms "comprising," "having," "including," and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted. Additionally, whenever a composition is given herein, it is understood that the composition can also comprise, consist essentially of, or consist of the stated ingredients, as appropriate, in any order.

[0063] The expression "bioequivalent" or "bioequivalence" is a term of art in the field and is intended to be defined in accordance with the U.S. Department of Health and Human Services publication, 34th Edition of the Orange Book for Evaluating Therapeutic Equivalency of Approved Drug Products (commonly referred to as the "Orange Book"). Bioequivalence of different formulations of the same drug substance involves equivalence with respect to the rate and extent of absorption of the drug. The extent and rate of absorption of a test formulation are compared to a reference formulation to determine whether the two formulations are bioequivalent. Standard bioequivalence studies are conducted in a crossover manner by widely testing a single dose of the test drug and a control drug in a number of volunteers (usually 12 to 24 healthy normal adults) and then measuring the blood or plasma levels of the drug over time. The FDA Office of Generic Drugs Bioequivalence Branch has published detailed guidelines for establishing bioequivalence of a formulation relative to a reference formulation.

[0064] As described herein, the term "mean" refers to the geometric mean determined from a series of independent measurements. For example, independent measurements can be collected from a statistically meaningful population. As other examples, when used to describe a pharmacokinetic parameter (such as "mean C max ", "mean AUC 0-x ", "mean AUC 0-t ", "mean AUC 0-inf ", "mean t max ", or "mean t 1 / 2 " (or "mean half-life")), "mean" refers to the geometric mean pharmacokinetic value derived from a population of individual measurements collected separately. Thus, as used herein, a dosage form can be administered to a human subject, wherein the dosage form has a mean pharmacokinetic value derived from a series of independent measurements.

[0065] A list of abbreviations and definitions used in this application is as follows. AUC: area under the plasma concentration-time curve; AUC 0-x : area under the plasma concentration-time curve from 0 hours to x hours post-dose (e.g., x can represent 12 or 24 hours); AUC 0-t : area under the plasma concentration-time curve from 0 hours to the last quantifiable concentration; AUC 0-inf : area under the plasma concentration-time curve from 0 hours to infinity; ANCOVA: analysis of covariance; CI: confidence interval; C max : maximum drug concentration; C x : plasma concentration at x hours post-dose; CV: coefficient of variation; LC-MS / MS: liquid chromatography-mass spectrometry / mass spectrometry; MAD: multiple ascending dose; MTD: maximum tolerated dose; PD: pharmacodynamics; PK: pharmacokinetics; RT: reaction time; SAD: single ascending dose; SD: standard deviation; t1 / 2: terminal elimination half-life; tmax : the time to reach maximum (peak) concentration after administration of a drug. As used herein, t 1 / 2 includes the terminal elimination half-life of the drug concentration, which can be C max : the terminal elimination half-life of the drug concentration. As used herein, C max includes the maximum drug concentration of a substance measured in human plasma.

[0066] Two dosage forms are generally considered "bioequivalent" if the rate and extent of their absorption are not significantly different. Another method for average bioequivalence involves calculating the 90% confidence interval for the ratio of the means (population geometric means) of the test and reference products. To establish BE, the calculated confidence interval should generally fall within 80-125% of the ratio of the product means. In addition to this conventional method, other methods can be used for the establishment of bioequivalence, including (1) log-transformation of the pharmacokinetic data, (2) methods to assess sequence effects, and (3) methods to assess outlying data. For example, in (1) above, the confidence interval should generally fall within 80-125% of the difference in the mean values of the log-transformed PK parameters.

[0067] The terms "about," "approximately," or "around" as used herein when referring to a measurable quantity such as an amount, a time interval, and the like, is meant to encompass deviations or variations of ±20% or ±10%, more preferably ±5%, even more preferably ±1%, and still more preferably ±0.1% of the specified value, as long as such a deviation or variation is appropriate in the given context.

[0068] When a dosage value or dosage range is referred to in terms of mass or weight of "a compound of Formula I" or "H3B-6545" or "the free base of H3B-6545", one skilled in the art will appreciate that providing an equimolar amount of active compound as a pharmaceutically acceptable salt generally requires administration of a greater mass of the salt than would be required if the compound itself were administered (i.e., the amount of free base and the amount of salt have a 1 : 1 molar ratio). For example, the phrase "25 mg to 50 mg of a compound of Formula I or a pharmaceutically acceptable salt thereof" contemplates amounts of the free base of Formula I from 25 mg to 50 mg (inclusive of the endpoints), as well as amounts of the monohydrochloride salt of Formula I from 26 mg to 53 mg (inclusive of the endpoints). This conversion can be referred to as, for example, a "salt conversion factor", a "salt correction factor", or a "potency adjustment factor".

[0069] The potency-modulating factor conversion also applies to crystalline forms of Formula I that exist as hydrates, solvates, or crystalline forms of Formula I that have both i) a hydrate or solvate and ii) a salt counterion. Moreover, such potency-modulating factor conversion can apply whether the co-crystallized solvent molecules and / or salt counterions are present in the crystalline form in whole number or non- whole number stoichiometric ratios. Thus, one skilled in the art understands that different potency-modulations can be made for the monohydrochloride salt of H3B-6545, the hemihydrochloride salt of H3B-6545, or special ratios such as 1 : 1.3, 1 : 1.25, and the like.

[0070] Consistent with the preceding paragraph, as used herein, an "equivalent" amount (e.g., mass, weight, dose, etc.) of Formula I (or H3B-6545, the free base of H3B-6545, or any other synonym thereof used herein) refers to an amount of any salt and / or hydrate that follows its potency-modulating factor.

[0071] "H3B-6545 drug substance" refers to the monohydrochloride salt of H3B-6545 as reported in U.S. Patent No. 10,640,483, which is incorporated herein by reference.

[0072] As used herein, "human subject" is interchangeable with "human subject in need of treatment," "human subject in need," and refers to a human subject having breast cancer, or a human subject having an increased risk of developing breast cancer relative to the general population. A human subject in need can be one who has been previously diagnosed or identified as having breast cancer or a precancerous condition. Alternatively, a human subject in need can be one who has an increased risk of developing such a condition relative to the general population (i.e., a subject who is predisposed to developing such a condition relative to the general population). A human subject in need can have a precancerous condition.

[0073] A human subject in need can have a refractory or resistant cancer (i.e., a cancer that is unresponsive to treatment or has not yet responded to treatment). The subject can be resistant at the start of treatment or can become resistant during treatment. In some embodiments, a subject in need has a recurrence of cancer after a recent therapy has been in remission. In some embodiments, a subject in need has received all known effective therapies for the treatment of cancer and has failed each. In some embodiments, a subject in need has received at least one prior therapy, and in preferred embodiments, the subject has a cancer or cancerous condition.

[0074] As used herein, "fasted conditions" describes a human subject in need thereof who fasts overnight for at least 10 hours prior to administration. No food is allowed for at least 4 hours after dosing. Water can be allowed as needed except for 1 hour prior to and after drug administration.

[0075] As used herein, "fed state" describes a human subject who eats a high fat breakfast within 30 minutes or less after an overnight fast of at least 10 hours, and then takes a single dose of H3B-6545 within 30 minutes after starting the meal. Water can be allowed as needed except for 1 hour prior to and after drug administration.

[0076] As used herein, "treating" or "treat" describes the management and care of a human subject for the purpose of combating the disease, condition, or disorder to alleviate the symptoms or complications of the disease, condition, or disorder, or to eliminate the disease, condition, or disorder.

[0077] H3B-6545 or a pharmaceutically acceptable salt and / or solvate thereof can also be used to prevent the relevant disease, condition, or disorder, or to identify suitable candidates for such purposes. As used herein, "prevent," "preventing," or "protection" describes reducing or eliminating the occurrence of symptoms or complications of such a disease, condition, or disorder.

[0078] As used herein, "sample" means any biological sample derived from a human subject, including but not limited to cells, tissue samples, body fluids (including but not limited to mucus, blood, plasma, serum, urine, saliva, and semen), tumor cells, and tumor tissue. Preferably, the sample is selected from the group consisting of bone marrow, peripheral blood cells, blood, plasma, and serum. The sample can be provided by a subject who is under treatment or testing. Alternatively, the sample can be obtained by a physician according to routine procedures in the art.

[0079] As used herein, the term "dosage form" refers to a physically discrete unit appropriate for a unitary dosages for human subjects to be treated; each unit containing a predetermined quantity of active compound calculated to produce the desired therapeutic effect, in association with the required pharmaceutical carrier. Dosage forms are classified by route and site of application, including, for example, oral, topical, rectal, vaginal, intravenous, subcutaneous, intramuscular, ophthalmic, nasal, ocular, and inhalant administration. Alternatively, dosage forms are classified by physical form, such as solid, semi-solid, or liquid. Dosage forms are any of a variety of forms, including, for example, IV bags, tablets, single pumps on an aerosol inhaler, or ampoules. "Oral dosage form" refers to a dosage form that is readily administered to a human subject by mouth. Non-limiting examples of oral dosage forms include capsules and tablets. The amount of active ingredient (e.g., a formulation of a disclosed compound or salt, hydrate, or solvate thereof) in a unit dose of composition is an effective amount and varies according to the particular treatment involved, as well as the subject being treated.

[0080] As used herein, the phrase "pharmaceutically acceptable" refers to those compounds, materials, compositions, carriers, and / or dosage forms that are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit / risk ratio.

[0081] As used herein, the phrase "pharmaceutically acceptable excipient" means an excipient that is useful in preparing a pharmaceutical composition that is generally safe, non-toxic, and neither biologically nor otherwise undesirable, and includes an excipient that is acceptable for veterinary use as well as for human pharmaceutical use. The use of "pharmaceutically acceptable excipient" in the specification and claims includes a pharmaceutically acceptable excipient that is one or more excipients. For example, a pharmaceutically acceptable excipient for use in the formulations of the present application can be a diluent or inert carrier, lubricant, binder, or combination thereof. A pharmaceutically acceptable excipient for use in the formulations of the present application can also include a filler, antimicrobial agent, antioxidant, anticaking agent, coating agent, or mixture thereof.

[0082] The term "composition" as used herein is intended to encompass a product comprising the specified ingredients in the specified amounts, as well as any product which results, directly or indirectly, from combining the specified ingredients in the specified amounts. In relation to pharmaceutical compositions, the term is intended to encompass a product comprising the active ingredient (here, any of Formula I or a pharmaceutically acceptable salt, hydrate, and / or solvate thereof) and the inert ingredient(s) that make up the carrier, as well as any product which results, directly or indirectly, from combination, complexation or aggregation of any two or more ingredients, or from dissociation of one or more ingredients, other types of reactions or interactions. Accordingly, the pharmaceutical compositions of the present application encompass any composition made by admixing a compound of Formula I (or a pharmaceutically acceptable salt, hydrate, and / or solvate) with a pharmaceutically acceptable excipient.

[0083] As used herein, the term "therapeutically effective amount" means the amount of H3B-6545 that is capable of producing a therapeutic effect in a human subject. A therapeutically effective amount is an amount that is capable of treating, ameliorating, or preventing an identified disease or condition, or that shows a detectable therapeutic or inhibitory effect. The effect can be detected by any assay known in the art. The precise effective amount for a subject will depend upon the subject's body weight, size, and health; the nature and extent of the symptoms; and the therapeutic agent selected for administration. The therapeutically effective amount for a given situation can be determined by routine experimentation that is within the skill and judgment of the physician.

[0084] In a preferred aspect, the disease or condition to be treated is cancer. In another aspect, the disease or condition to be treated is a cell proliferative disorder. A therapeutically effective amount of H3B-6545 can be administered in a dosage form. The therapeutically effective amount of H3B-6545 can be in the form of a pharmaceutically acceptable salt, solvate, and / or hydrate.

[0085] As used herein, a "therapeutic effect" is the consequence of any kind of medical treatment which is judged to be desirable and beneficial. This is true regardless of whether the consequence is anticipated, unanticipated, or even an unintended consequence of the treatment. The desirable or beneficial consequence can be the inhibition of an altered cellular signaling pathway, the inhibition of cell growth (preferably cancer cell growth), the promotion of cell death (preferably cancer cell death), or the shrinkage of a tumor, all without observing serious side effects. The slowing of the growth of a tumor, preferably its regression, and even more preferably the complete regression of a cancer is another example of a therapeutic effect. A therapeutic effect can also be an objectively identifiable improvement noted by a physician or other qualified observer, for example, tumor regression in a patient can be measured with respect to the diameter of a tumor. A decrease in the diameter of a tumor indicates regression. The lack of recurrence of a tumor after termination of treatment also indicates regression.

[0086] Serious side effects can include life-threatening side effects (such as liver failure, abnormal heart rate, and certain types of allergic reactions), side effects that result in persistent or severe disability or hospitalization, or side effects that cause birth defects.

[0087] As used herein, "pharmaceutically acceptable salts" refer to derivatives of H3B-6545 wherein the parent compound is modified by making acid or base salts of the parent compound. Examples of pharmaceutically acceptable salts include, but are not limited to, mineral or organic acid salts of basic residues such as amines, alkali or organic salts of acidic residues such as carboxylic acids, and the like. The pharmaceutically acceptable salts include the conventional nontoxic salts or the quaternary ammonium salts of the parent compound formed, for example, from non-toxic inorganic or organic acids.

[0088] As used herein, "quantifiable" means capable of being measured, calculated, or expressed as a quantity or numerical value. A quantifiable plasma concentration is a concentration of H3B-6545 that can be detected and measured in the plasma of a human subject after administration. A quantifiable AUC bioavailability is a fraction of H3B-6545 that enters the systemic circulation of a human subject that can be calculated from the plasma concentrations of H3B-6545 in plasma samples collected from the human subject over a set period of time. A quantifiable half-life is a detectable or calculable time in which the plasma concentration of H3B-6545 is 50% of the maximum quantifiable plasma concentration of H3B-6545. Methods and materials necessary to quantify the above-mentioned PK parameters are generally known to those of ordinary skill in the art. Specific quantification methods are presented in the present application.

[0089] As used herein, the term "solvate" means a solvent addition form containing either a stoichiometric or non-stoichiometric amount of solvent.

[0090] As used herein, the term "tautomer" means one of two or more structural isomers that exist in equilibrium and are readily converted from one isomer to another.

[0091] Unless specifically noted otherwise or apparent from context, as used herein the term "or" is to be understood as inclusive.

[0092] One aspect of the present application provides a dosage form having a therapeutically effective amount of H3B-6545 or a pharmaceutically acceptable salt thereof and at least one pharmaceutically acceptable carrier or excipient, which is capable of administering to a human subject in need thereof, wherein the therapeutically effective amount achieves a quantifiable plasma concentration after administration. In one embodiment of the present application, the dosage form is an oral dosage form. In another embodiment of the present application, the dosage form is a solid dosage form. In another embodiment of the present application, the dosage form is a solid oral dosage form. In yet another embodiment, the solid oral dosage form can be an immediate release oral solid dosage form. The oral solid dosage form can be in the form of a tablet or a capsule. These forms can have multiple phases, including, for example, an inner phase and an outer phase.

[0093] In one embodiment, the dosage form is substantially free of water. By "substantially" free of water in this context, it is meant that the water content of the formulation at the time of packaging is less than 7% of the total weight of the formulation, less than 5% of the total weight of the formulation, less than 1% of the total weight of the formulation, or less than 0.5% of the total weight of the formulation. In one embodiment, the amount of water is between 0.1 and 5% of the total weight of the formulation (e.g., 0.1-1% or 0.1-0.5%). In one embodiment, the amount of water in the formulation of the present application manufactured by a spray coating process is less than 0.5%.

[0094] The at least one pharmaceutically acceptable excipient can be a diluent or inert carrier, a disintegrant, a lubricant, a binder, or a combination thereof. The pharmaceutically acceptable excipient can also include a filler, an antimicrobial agent, an antioxidant, an anticaking agent, a coating agent, or a mixture thereof.

[0095] Exemplary binders can include, but are not limited to, corn starch, potato starch, other starches, gelatin, natural and synthetic gums such as acacia, xanthan gum, sodium alginate, alginic acid, other alginates, powdered tragacanth, guar gum, cellulose and its derivatives (e.g., ethyl cellulose, cellulose acetate, carboxymethyl cellulose calcium, sodium carboxymethyl cellulose), polyvinyl pyrrolidone (e.g., povidone, cross-linked povidone, copovidone, etc.), methyl cellulose, methocel, pregelatinized starch (e.g., STARCH 1500® and STARCH and STARCH 1500 Explotab), potato or tapioca starch, other starches, pre-gelatinized starch, clays, other alginins, other celluloses, gums such as gellan, low-substituted hydroxypropyl cellulose, ployplasdone, or mixtures thereof.

[0096] Exemplary disintegrants can include, but are not limited to, guar gum, alginic acid, calcium carbonate, microcrystalline cellulose, croscarmellose sodium, crospovidone, polacrilin potassium, sodium starch glycolate (such as Explotab), potato or tapioca starch, other starches, pre-gelatinized starch, clays, other alginins, other celluloses, gums such as gellan, low-substituted hydroxypropyl cellulose, ployplasdone, or mixtures thereof.

[0097] Exemplary lubricants can include, but are not limited to, calcium stearate, magnesium stearate, mineral oil, light mineral oil, glycerin, sorbitol, mannitol, polyethylene glycol, other glycols, compritol, stearic acid, sodium lauryl sulfate, sodium stearyl fumarate (such as Pruv), vegetable based fatty acid lubricants, talc, hydrogenated vegetable oil (e.g., peanut oil, cottonseed oil, sunflower oil, sesame oil, olive oil, corn oil, and soybean oil), zinc stearate, ethyl oleate, ethyl laureate, agar, syloid silica aerogel (AEROSIL 200, W.R. Grace Co., Baltimore, MD USA), an agglomeration of synthetic silica (Deaussa Co., Piano, TX USA), pyrogenic silica (CAB-O-SIL, Cabot Co., Boston, MA USA), or mixtures thereof.

[0098] Exemplary coating agents can include, but are not limited to, sodium carboxymethyl cellulose, cellulose acetate phthalate, ethyl cellulose, gelatin, pharmaceutical glaze, hydroxypropyl cellulose, hydroxypropyl methyl cellulose (hypromellose), hydroxypropyl methyl cellulose phthalate, methyl cellulose, polyethylene glycol, polyvinyl acetate phthalate, shellac, sucrose, titanium dioxide, carnauba wax, microcrystalline wax, gellan gum, maltodextrin, methacrylic acid, microcrystalline cellulose, and carrageenan, or mixtures thereof.

[0099] In one embodiment, the dosage form is a solid oral dosage form, which is optionally treated with a coating system (e.g., Opadry® fx film coating system) to be coated with, for example, Opadry® blue (OY-LS-20921), Opadry® white (YS-2-7063), Opadry® white (YS-1-7040), and Opadry® black ink (S-1-8 106).

[0100] In one embodiment, the oral dosage form is configured as a capsule having an inner phase comprising a therapeutically effective amount of H3B-6545 or a pharmaceutically acceptable salt thereof, lactose monohydrate, low-substituted hydroxypropyl cellulose, microcrystalline cellulose, hydroxypropyl cellulose, and colloidal anhydrous silica. The capsule also has an outer phase comprising magnesium stearate.

[0101] In one embodiment, the capsule is hypromellose.

[0102] In another embodiment, the capsule is hypromellose, and further comprises iron oxide red and titanium dioxide.

[0103] In another embodiment, the oral dosage form is a capsule comprising 25% to 30% by total weight of the capsule of a therapeutically effective amount of H3B-6545 or a pharmaceutically acceptable salt, 10% to 15% lactose monohydrate, 5% to 10% low-substituted hydroxypropyl cellulose, 1% to 5% microcrystalline cellulose, 0.5% to 5% hydroxypropyl cellulose, 0.05% to 0.5% colloidal anhydrous silica, 0.1% to 1% magnesium stearate, 40% to 45% hypromellose, 0.5% to 2% iron oxide red, and 0.5% to 2% titanium dioxide.

[0104] Pharmaceutically acceptable salts can include conventional nontoxic salts or quaternary ammonium salts of a parent compound formed, for example, from non-toxic inorganic or organic acids. Such conventional nontoxic salts include, but are not limited to, those derived from inorganic and organic acids selected from 2-acetoxybenzoic, 2-hydroxyethanesulfonic, acetic, ascorbic, benzenesulfonic, benzoic, bicarbonic, carbonic, citric, edetic, ethane disulfonic, 1,2-ethanedisulfonic, fumaric, glucoheptonic, gluconic, glutamic, glycolic, glycollyarsanilic, hexylic resorcic, hydrabamic, hydrobromic, hydrochloric, hydroiodic, hydroxymaleic, hydroxynaphthalene carboxylic, isethionic, lactic, lactobionic, lauryl sulfonic, maleic, malic, mandelic, methanesulfonic, naphthalene sulfonic, nitric, oxalic, pamoic, pantothenic, phenylacetic, phosphoric, polygalacturonic, propionic, salicylic, stearic, subacetic, succinic, sulfamic, sulfanilic, sulfuric, tannic, tartaric, toluenesulfonic, and the like, and the common amine acids such as glycine, alanine, phenylalanine, arginine, etc.

[0105] Other examples of pharmaceutically acceptable salts can include hexanoic, cyclopentanepropionic, pyruvic, malonic, 3-(4-hydroxybenzoyl)benzoic, cinnamic, 4-chlorobenzenesulfonic, 2-naphthalenesulfonic, 4-methylvaleric, camphorsulfonic, 4-methyldicyclo-[2.2.2]-oct-2-ene-l-carboxylic, 3-phenylpropionic, trimethylacetic, tert-butylacetic, muconic, etc. The present application also contemplates salts formed when acidic protons present in the parent compound are replaced by a metal ion, e.g., alkali metal ions, alkaline earth ions, or aluminum ions, or coordinates with an organic base, such as ethanolamine, diethanolamine, triethanolamine, tromethamine, N-methylglucamine, etc. In salt forms, it is understood that the ratio of the compound to the cation or anion of the salt can be 1:1, or any ratio other than 1:1, such as 3:1, 2:1, 1:2, or 1:3.

[0106] In another embodiment, the dosage form can further comprise one or more active compounds (e.g., H3B-6545 or a salt thereof) in combination with at least one pharmaceutically acceptable excipient or carrier.

[0107] Examples of solvates can include the following: if the solvent is water, the solvate formed is a hydrate; if the solvent is alcohol, the solvate formed is an alcoholate. A hydrate is formed by the combination of one or more molecules of water with one molecule of a substance, in which the water retains its molecular state as H2O. A hemi-hydrate is formed by the combination of one molecule of water with one molecule of a substance, in which the water retains its molecular state as H2O

[0108] An oral dosage form having a therapeutically effective amount of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier or excipient can achieve a quantifiable plasma concentration from about 0.5 hours to about 12 hours, from about 0.5 hours to about 5 hours, from about 0.5 hours to about 3 hours, from about 1 hour to about 5 hours, or from about 1 hour to about 3 hours after administration, wherein the oral dosage form is capable of being administered to a human subject in need thereof.

[0109] A therapeutically effective amount of H3B-6545, or a pharmaceutically acceptable salt thereof, that can be present in an oral dosage form is in the range of from about 50 mg to about 1000 mg, from about 100 mg to about 800 mg, from about 100 mg to about 600 mg, from about 200 mg to about 600 mg, or from about 400 mg to about 600 mg.

[0110] In a preferred embodiment, a therapeutically effective amount of H3B-6545, or a pharmaceutically acceptable salt thereof, that can be present in an oral dosage form is 450 mg. In one embodiment of the present application, the above dosage is a daily dosage.

[0111] An oral dosage form having a therapeutically effective amount of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier or excipient can achieve a maximum quantifiable plasma concentration from about 170 ng / mL to about 2000 ng / mL, from about 200 ng / mL to about 1500 ng / mL, from about 500 ng / mL to about 2000 ng / mL, from about 500 ng / mL to about 1500 ng mL, from about 1000 ng / mL to about 2000 ng / mL, or from about 1000 ng / mL to about 1500 ng / mL after administration, wherein the oral dosage form is capable of being administered to a human subject in need thereof.

[0112] An oral dosage form having a therapeutically effective amount of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier or excipient can achieve a half-life from about 5 hours to about 24 hours, from about 8 hours to about 24 hours, from about 8 hours to about 15 hours, from about 10 hours to about 15 hours, or from about 15 hours to about 24 hours after administration, wherein the oral dosage form is capable of being administered to a human subject in need thereof.

[0113] An oral dosage form having a therapeutically effective amount of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier or excipient can achieve a quantifiable AUC bioavailability of about 2,000 ng*hr / mL to about 20,000 ng*hr / mL, about 5,000 ng*hr / mL to about 20,000 ng*hr / mL, about 10,000 ng*hr / mL to about 20,000 ng*hr / mL, about 15,000 ng*hr / mL to about 20,000 ng*hr / mL, about 5,000 ng*hr / mL to about 15,000 ng*hr / mL, or about 10,000 ng*hr / mL to about 15,000 ng*hr / mL after administration to a human subject in need thereof, wherein the oral dosage form is capable of administration to a human subject in need thereof.

[0114] An oral dosage form having a therapeutically effective amount of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier or excipient can be administered orally once daily in a single dose during a 20-day cycle, a 21-day cycle, a 22-day cycle, a 23-day cycle, a 24-day cycle, a 25-day cycle, a 26-day cycle, a 27-day cycle, a 28-day cycle, or until a therapeutic effect occurs in a subject in need thereof, wherein the oral dosage form is capable of administration to a human subject in need thereof. The dosage form can also be administered in cycles of less than 20 days.

[0115] A. An oral dosage form comprising about 100 mg to about 600 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient.

[0116] In some embodiments, the oral dosage form comprises about 100 mg to about 600 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In such embodiments, the dosage achieves a maximum quantifiable plasma concentration Cmax(in ng / mL) after administration to a subject in need of treatment of about 150 ng / mL to about 2100 ng / mL. In other embodiments, the dosage achieves a maximum quantifiable plasma concentration after administration to a subject in need of treatment of about 250 ng / mL to about 1700 ng / mL. In other embodiments, the dosage achieves a maximum quantifiable plasma concentration after administration to a subject in need of treatment of about 1200 ng / mL to about 1500 ng / mL. In these embodiments, the Cmaxis achieved within a time period of about 1 hour to about 25 hours; about 2 hours to about 12 hours; about 2 hours to about 5 hours; or about 4 hours.

[0117] In one embodiment, the oral dosage form comprises about 100 to 600 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In such embodiments, the oral dosage form is capable of achieving a Cmax range of about 1.8 ng / mL to about 4.0 ng / mL per mg of H3B-6545. In another embodiment, the oral dosage form is capable of achieving a Cmax range of about 1.8 ng / mL to about 3.4 ng / mL per mg of H3B-6545. In yet other embodiments, the oral dosage form is capable of achieving a Cmax range of about 3.0 ng / mL to about 4.0 ng / mL per mg of H3B-6545.

[0118] In some embodiments, the oral dosage form comprises about 100 mg to about 600 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In some of the above embodiments, the dosage form achieves a half-life of about 8.0 hours to about 22.0 hours; or a half-life of about 10.0 hours to about 13.0 hours after administration to a human subject in need thereof.

[0119] In one embodiment, the oral dosage form comprises about 100 mg to about 600 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In such embodiments, the dosage is capable of achieving a quantifiable AUC bioavailability (0-24 hours) of from about 1,600 ng*hr / mL to about 23,000 ng*hr / mL; about 2,500 ng*hr / mL to about 18,500 ng*hr / mL; about 4,000 ng*hr / mL to about 20,000 ng*hr / mL; or about 9,000 ng*hr / mL to about 17,000 ng*hr / mL after administration to a human subject in need thereof.

[0120] In one embodiment, the oral dosage form comprises from about 100 mg to about 600 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In such embodiments, the dosage is capable of achieving a quantifiable AUC bioavailability (0-24 hours) of about 17 ng*hr / mL / mg to about 40 ng*hr / mL / mg; about 17 ng*hr / mL / mg to about 37 ng*hr / mL / mg, or about 26 ng*hr / mL / mg to about 40 ng*hr / mL / mg after administration to a human subject in need thereof, wherein the quantifiable AUC bioavailability (0-24 hours) is measured on a "per milligram of H3B-6545" basis.

[0121] In one embodiment, the oral dosage form comprises from about 100 mg to about 600 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In such embodiments, the dosage form can achieve a quantifiable AUC bioavailability (0-inf) of from about 2,000 ng*hr / mL to about 40,000 ng*hr / mL; about 5,000 ng*hr / mL to about 25,000 ng*hr / mL, or about 20,000 ng*hr / mL to about 23,000 ng*hr / mL following administration to a human subject in need thereof.

[0122] In one embodiment, the oral dosage form comprises from about 100 mg to about 600 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In such embodiments, the dosage form can achieve a quantifiable AUC bioavailability (0-inf) of from about 2,000 ng*hr / mL to about 40,000 ng*hr / mL; about 5,000 ng*hr / mL to about 25,000 ng*hr / mL, or about 20,000 ng*hr / mL to about 23,000 ng*hr / mL following administration to a human subject in need thereof.

[0123] B. an oral dosage form comprising from about 300 mg to about 600 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient.

[0124] In some embodiments, the oral dosage form comprises from about 300 mg to about 600 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In such embodiments, the dosage form achieves a maximum quantifiable plasma concentration Cmax (in ng / mL) of from about 900 ng / mL to about 2100 ng / mL following administration to a subject in need of treatment. In other embodiments, the dosage form achieves a maximum quantifiable plasma concentration of from about 1100 ng / mL to about 1900 ng / mL following administration to a subject in need of treatment. In other embodiments, the dosage form achieves a maximum quantifiable plasma concentration of from about 1200 ng / mL to about 1700 ng / mL following administration to a subject in need of treatment. In these embodiments, the Cmax can be achieved within a time of from about 1 hour to about 25 hours; from about 2 hours to about 10 hours; from about 2 hours to about 5 hours; or about 4 hours.

[0125] In one embodiment, the oral dosage form comprises from about 300 to 600 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In such embodiments, the oral dosage form is capable of achieving a Cmax range of about 3.0 ng / mL to about 4.0 ng / mL per mg of H3B-6545. In another embodiment, the oral dosage form is capable of achieving a Cmax range of about 3.0 ng / mL to about 3.4 ng / mL per mg of H3B-6545.

[0126] In some embodiments, the oral dosage form comprises from about 300 mg to about 600 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In some of the above embodiments, the dosage form achieves a half-life of about 9.5 hours to about 14.5 hours; or a half-life of about 10.0 hours to about 11.0 hours after administration to a human subject in need thereof.

[0127] In one embodiment, the oral dosage form comprises from about 300 mg to about 600 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In such embodiments, the dosage is capable of achieving a quantifiable AUC bioavailability (0-24 hours) of about 9,000 ng*hr / mL to about 23,000 ng*hr / mL or about 12,000 ng*hr / mL to about 19,000 ng*hr / mL after administration to a human subject in need thereof.

[0128] In one embodiment, the oral dosage form comprises from about 300 mg to about 600 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In such embodiments, the dosage is capable of achieving a quantifiable AUC bioavailability (0-24 hours) of about 30 ng*hr / mL / mg to about 40 ng*hr / mL / mg or about 30 ng*hr / mL / mg to about 37 ng*hr / mL / mg after administration to a human subject in need thereof, wherein the quantifiable AUC bioavailability (0-24 hours) is measured on a "per milligram of H3B-6545" basis.

[0129] In one embodiment, the oral dosage form comprises from about 300 mg to about 600 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In such embodiments, the dose can achieve a quantifiable AUC bioavailability (0-inf) of from about 11,000 ng*hr / mL to about 40,000 ng*hr / mL; from about 11,000 ng*hr / mL to about 33,000 ng*hr / mL, or from about 12,000 ng*hr / mL to about 40,000 ng*hr / mL, as measured on a "per mg of H3B-6545" basis, following administration to a human subject in need thereof.

[0130] In one embodiment, the oral dosage form comprises from about 300 mg to about 600 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In such embodiments, the dose can achieve a quantifiable AUC bioavailability (0-inf) of from about 11,000 ng*hr / mL to about 40,000 ng*hr / mL; from about 11,000 ng*hr / mL to about 33,000 ng*hr / mL, or from about 12,000 ng*hr / mL to about 40,000 ng*hr / mL, as measured on a "per mg of H3B-6545" basis, following administration to a human subject in need thereof.

[0131] C. an oral dosage form comprising about 450 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient.

[0132] In some embodiments, the oral dosage form comprises about 450 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In such embodiments, the dose achieves a maximum quantifiable plasma concentration Cmax (in ng / mL) of from about 1,000 ng / mL to about 1,600 ng / mL following administration to a subject in need of treatment. In other embodiments, the dose achieves a maximum quantifiable plasma concentration of from about 1,100 ng / mL to about 1,500 ng / mL following administration to a subject in need of treatment. In other embodiments, the dose achieves a maximum quantifiable plasma concentration of from about 1,200 ng / mL to about 1,400 ng / mL following administration to a subject in need of treatment. In these embodiments, the Cmax is achieved within a time of from about 3 hours to about 6 hours or from about 4 hours to about 6 hours.

[0133] In one embodiment, the oral dosage form comprises about 450 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In such embodiments, the oral dosage form is capable of achieving a Cmax range of about 2.4 ng / mL to about 3.5 ng / mL per mg of H3B-6545. In another embodiment, the oral dosage form is capable of achieving a Cmax range of about 3.0 ng / mL to about 3.5 ng / mL per mg of H3B-6545. In yet other embodiments, the oral dosage form is capable of achieving a Cmax range of about 3.3 ng / mL to about 3.5 ng / mL per mg of H3B-6545.

[0134] In some embodiments, the oral dosage form comprises about 450 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In some of the above embodiments, the dosage form achieves a half-life of about 8.0 hours to about 11.0 hours; or a half-life of about 9.0 hours to about 10.0 hours upon administration to a human subject in need thereof.

[0135] In one embodiment, the oral dosage form comprises about 450 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In such embodiments, the dosage is capable of achieving a quantifiable AUC bioavailability (0-24 hours) of from about 12,000 ng*hr / mL to about 20,000 ng*hr / mL; about 14,000 ng*hr / mL to about 16,000 ng*hr / mL, or about 12,000 ng*hr / mL to about 17,000 ng*hr / mL upon administration to a human subject in need thereof.

[0136] In one embodiment, the oral dosage form comprises about 450 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In such embodiments, the dosage is capable of achieving a quantifiable AUC bioavailability (0-24 hours) of about 27 ng*hr / mL / mg to about 43 ng*hr / mL / mg; about 30 ng*hr / mL / mg to about 40 ng*hr / mL / mg, or about 30 ng*hr / mL / mg to about 35 ng*hr / mL / mg upon administration to a human subject in need thereof, wherein the quantifiable AUC bioavailability (0-24 hours) is measured on a "per milligram of H3B-6545" basis.

[0137] In one embodiment, the oral dosage form comprises about 450 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In such an embodiment, the dose can achieve a quantifiable AUC bioavailability (0-infinity) of about 16,000 ng*hr / mL to about 26,000 ng*hr / mL; about 16,000 ng*hr / mL to about 23,000 ng*hr / mL, or about 16,000 ng*hr / mL to about 18,000 ng*hr / mL after administration to a human subject in need thereof.

[0138] In one embodiment, the oral dosage form comprises about 450 mg of H3B-6545, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient. In such an embodiment, the dose can achieve a quantifiable AUC bioavailability (0-infinity) of about 36 ng*hr / mL / mg to about 57 ng*hr / mL / mg; about 38 ng*hr / mL / mg to about 52 ng*hr / mL / mg, or about 35 ng*hr / mL / mg to about 40 ng*hr / mL / mg after administration to a human subject in need thereof, wherein the quantifiable AUC bioavailability (0-infinity) is measured on a "per milligram of H3B-6545" basis.

[0139] Embodiments can also relate to methods for treating breast cancer (i.e., ERa-positive and / or HER2-negative cancer), wherein the methods comprise administering to a human subject in need thereof any of the oral dosage forms described herein to achieve the PK results described.

[0140] In all embodiments relating to methods of treatment, the human subject in need can be in a fed or fasted state.

[0141] Nonclinical findings support dose-dependent inhibition of ERaWT and ERa mut-dependent transcription and subsequent reduction in cell proliferation. Safety, pharmacokinetics (PK), and pharmacodynamics (PD) of H3B-6545 in women with ER+, HER2-negative breast cancer (BC) were considered to identify the recommended Phase 2 dose (RP2D).

[0142] Mutations in the constitutively activated ESR1 gene, which are found in ~30% of MBC tumors, are located in the ligand binding domain and confer resistance to estrogen deprivation therapy (e.g., aromatase inhibition) and promote resistance to anti-ER therapy. Li S., et al., Cell Reports, 2013; 4: 1116-1130; Robinson DR, Wu YM, Vats P, et al., Nature genetics, 2013; 45: 1446-1451; Toy W, Shen Y, Won H, et al., Nature genetics. 2013; 45: 1439-1445.

[0143] H3B-6545 is an orally available, selective ER covalent antagonist that simultaneously inhibits both estrogen receptor alpha (ERa) mutant (MUT) and wild type (WT) activity by irreversibly engaging with a non-conserved unique cysteine in other nuclear hormone receptors. H3B-6545 effectively suppresses ERa function without degrading the receptor.

[0144] The embodiments provide methods of treating a patient with H3B-6545, or a pharmaceutically acceptable salt thereof, comprising identifying whether a reduction in one or more mutant allele frequencies is observed in the patient's blood, selecting a patient in which the reduction is observed, and administering to the selected patient a therapeutically effective amount of H3B-6545, or a pharmaceutically acceptable salt thereof. A mutant allele frequency is the relative frequency of a mutant allele (variant of a gene) at a particular locus in a population, which is expressed as a fraction or percentage.

[0145] Applicants reported a Phase 1 dose escalation of H3B-6545, a first-in-class highly selective ERa covalent antagonist (SERCA), in women with ER-positive, HER2-negative breast cancer (HR+ BC). EMBODIMENTS

[0146] Example 1: Capsule formulation

[0147] Example 1 reports capsule formulations with various amounts of H3B-6545 drug substance. The capsules used in the subsequent examples were also prepared using this method. The 25 mg, 50 mg, and 150 mg strength capsules were formulated according to the following table:

[0148] Table 1: Components and composition of H3B-6545 capsules

[0149]

[0150] NF = United States Pharmacopeia (US), Ph. Eur. = European Pharmacopoeia, JP = Japanese Pharmacopoeia a: The amount of H3B-6545 drug substance is adjusted according to the potency adjustment factor, which is a derived value of the assay value in free form.

[0151] b: The amount of lactose monohydrate is adjusted according to the amount of H3B-6545 drug substance to maintain a constant weight of the powder.

[0152] c: The components and compositions of the hypromellose capsules are provided in Tables 2 and 3.

[0153] d: Applicable to JP 16 Official Monograph "Capsules" or JP 17 Official Monograph "Hypromellose Capsules".

[0154] Table 2: Components and compositions of the hypromellose capsule shells for H3B-6545 25 and 150 mg capsules

[0155]

[0156] JPE = Japanese Pharmaceutical Excipients, NF = United States Pharmacopeia (US), JP = Japanese Pharmacopoeia,

[0157] USP = United States Pharmacopeia, EC Regulation = European Commission Regulation, Ph. Eur. = European Pharmacopoeia, q.s. = quantum sufficient. E172 is the European standard for iron oxide and hydroxide.

[0158] Table 3: Components and compositions of the hypromellose capsule shells for H3B-6545 50 mg capsules

[0159]

[0160] JPE = Japanese Pharmaceutical Excipients, NF = United States Pharmacopeia (US), JP = Japanese Pharmacopoeia,

[0161] USP = United States Pharmacopeia, EC Regulation = European Commission Regulation, Ph. Eur. = European Pharmacopoeia,

[0162] Table 2: Components and compositions of the hypromellose capsule shells for H3B-6545 25 and 150 mg capsules

[0163] Ingredients Description Composition (% w / w)

[0164] Pharmacopoeia, q.s. = quantum sufficient. E172 is the European standard for iron oxide and hydroxide.

[0165] Briefly, the capsules were prepared by forming an initial blend of H3B-6545 drug substance, lactose monohydrate, low-substituted hydroxypropylcellulose, microcrystalline cellulose, hydroxypropylcellulose, and colloidal silicon dioxide, anhydrous, in a high shear mixer. Magnesium stearate was then mixed with the initial blend using a high shear mixer. The resulting blend was then compressed into ribbons using a roller compactor, sieved, and mixed with magnesium stearate using a tumble mixer. The final blend was filled into hypromellose capsules using a encapsulator.

[0166] Example 2: Tablet formulation

[0167] Example 2 reports the formulation of tablets comprising H3B-6545 drug substance. The tablets discussed in the subsequent examples were prepared using this method. H3B-6545 film-coated tablets containing 150 mg of H3B-6545 drug substance as free base were prepared according to the following formulation:

[0168] Table 4: Composition of H3B-6545 tablets

[0169]

[0170]

[0171] JP = Japanese Pharmacopoeia, NC = Non-compendial, NF = National Formulary (US), Ph. Eur. = European Pharmacopoeia, q.s. = quantum sufficient, USP = United States Pharmacopeia.

[0172] a: The amount of H3B-6545 drug substance was adjusted by a potency adjustment factor, which is a derivative of the assay value in free form.

[0173] b: The amount of lactose monohydrate was adjusted to maintain a constant tablet weight according to the amount of H3B-6545 drug substance.

[0174] c: Removed in the drying process.

[0175] d: Adjusted proportionally to the yield of milled granules.

[0176] e: The components and composition of OPADRY 03H420000 YELLOW are described in the table.

[0177] f: Removed in the coating process.

[0178] Table 5: Components of 03H420000 YELLOW

[0179] Ingredients Description Hydroxypropyl Methylcellulose USP, Ph. Eur., JP Talc USP, Ph. Eur., JP Titanium Dioxide USP, Ph. Eur., JP Propylene Glycol USP, Ph. Eur., JP Iron Oxide (Yellow) NF, JPE, EC Regulation

[0180] EC Regulation = European Commission Regulation, JP = Japanese Pharmacopoeia, JPE = Japanese Pharmacopoeia Excipients, NF = National Formulary (US), Ph. Eur. = European Pharmacopoeia, USP = United States Pharmacopeia.

[0181] Tablets were formed in the following manner:

[0182] Lactose monohydrate, low-substituted hydroxypropylcellulose, hypromellose, and colloidal silicon dioxide were charged into a wet high shear granulator and mixed to form a first mixture. H3B-6545 drug substance and the first mixture were then charged into a convective mixer and mixed to form a second mixture.

[0183] The second mixture was continuously fed into a wet high shear granulator and granulated with a pump pouring pure water to form wet granules. The wet granules were continuously dried using a fluid bed dryer at elevated temperature until the dry loss of the dried granules reached no more than 1.5%.

[0184] The dried granules were then milled using a sieve mill. The milled granules, microcrystalline cellulose, and magnesium stearate were then charged into a convective mixer and mixed to form a mixed granule, which was compressed into a tablet core. A coating suspension (prepared by suspending a coating agent in pure water) was then sprayed onto the tablet core using a pan coater.

[0185] Blood samples were collected from each patient at scheduled time points and centrifuged. The plasma portion of each sample was then transferred to a K2EDTA tube and shipped to a bioanalytical laboratory for concentration measurement using LC-MS / MS. The concentration data were then analyzed using WinNonlin software to obtain PK parameters. The obtained PK parameters were further summarized using analysis software.

[0186] Blood samples (about 5 mL each) were collected from human patients pre-dose and at various hourly time points post-dose. Plasma concentrations of H3B-6545 were determined using a validated high performance liquid chromatography / tandem mass spectrometry (LC-MS / MS) method. The lower limit of quantitation was 0.100 ng / mL.

[0187] The PK analysis set included subjects who received H3B-6545 drug product in capsules or tablets and had sufficient valuable plasma concentration data to derive at least 1 primary PK parameter in each treatment. Plasma concentrations of H3B-6545 (as free base) were tabulated and summarized at each scheduled time using descriptive statistics (number of subjects, arithmetic mean of standard deviation [SD], coefficient of variation [CV%], geometric mean, median, minimum, and maximum) as appropriate. Individual and mean (± SD) plasma concentration-time curves were provided for each treatment.

[0188] Pharmacokinetic parameters for H3B-6545 were calculated using noncompartmental methods using models appropriate for plasma data and extravascular administration. PK parameters included, but were not limited to, area under the plasma concentration-time curve before the time of the last quantifiable concentration (AUC 0-t ), maximum concentration (C max ), and time of occurrence of maximum concentration (t max ). If data permitted, the area under the plasma concentration-time curve extrapolated to infinity (AUC 0-inf ), terminal elimination half-life (t 1 / 2 ), apparent total body clearance (CL / F), total systemic clearance following oral administration at steady state (CLss / F), apparent volume of distribution during the terminal phase (Vz / F), apparent steady-state volume of distribution (Vss), cumulative ratio of C max (RC max ), and cumulative ratio of AUC 0-24 (RAUC) were also derived.

[0189] Example 3: First Interim Analysis of Pharmacokinetics (PK) of Capsules in Fasted Patients Figure 1

[0190] Example 3 reports the clinical and genomic analysis of the single trial. The study population of Example 3 was as follows:

[0191] Female > 18 years of age with locally advanced or metastatic ER+ HER2- BC.

[0192] Progression after at least one hormonal therapy and at least one other therapy / treatment regimen; no maximum number of prior treatment lines.

[0193] ECOG performance status of 0 or 1.

[0194] Eligible bone marrow and organ function.

[0195] Excluded those with bone-only disease or inflammatory BC.

[0196] To determine if H3B-6545 inactivates both wild-type and mutant ERa by targeting cysteine 530 and stabilizing a unique antagonist conformation using method of analysis. Methods: Women with locally advanced or metastatic HR+ BC after progression on at least one hormonal therapy and at least one other regimen / therapy were treated (tx) with H3B-6545 drug product, administered orally by capsule once daily over a 28-day cycle. Dose escalation used a 3+3 design with backfilling of previously cleared doses and allowed intrapatient dose escalation. This example explored the safety, pharmacokinetics, and pharmacodynamics of H3B-6545 in women with HR+ BC to identify a recommended subsequent dose for testing.

[0197] Results: As of December 10, 2018, 32 patients have been treated with H3B-6545 drug product at doses from 100 to 450 mg / day; 97% had prior treatment with a CDK4 / 6 inhibitor, and 56% had received >3 prior anticancer therapy lines. No dose-limiting toxicities were observed, and only 1 grade 3 treatment-related adverse event (TRAE) (decrease in lymphocyte count) was observed.

[0198] The most common (>10%) TRAEs included asymptomatic sinus bradycardia, diarrhea, nausea, fatigue, anemia, decreased appetite, and hot flashes. H3B-6545 was rapidly absorbed with t max Plasma concentrations increased with doses from 100 to 450 mg, similar to C1D1 and C1D15. Consistent with the mechanism of action and preclinical data for H3B-6545, H3B-6545 inhibited ER target gene expression and showed a 50% reduction in Ki67 levels at all post-treatment dose levels. ESR1 (60%) and PIK3CA (34%) mutations were detected in plasma at baseline, and changes in mutant allele frequency appeared to correlate with response to treatment. Stable disease was observed in 15 patients (47%), and 34% of patients completed at least 6 months of treatment. Partial responses (PR) were observed in 3 patients: 1 patient (mutant) received 2 prior lines of therapy, and 2 patients (1 mutant and 1 wild-type) received >5 prior lines of therapy, including fulvestrant and capecitabine; all 3 patients had prior CDK4 / 6 inhibitors.

[0199] H3B-6545 drug product was well tolerated at up to 450 mg dose levels, with early signs of single-agent antitumor activity in the CDK4 / 6 post-background. Dose escalation continued in patients with advanced HER2-negative breast cancer.

[0200] Drug administration and dosing:

[0201] H3B-6545 was administered orally once daily for 28-day cycles.

[0202] Using a standard 3+3 study design, dose escalation was performed using dose cohorts of 100, 200, 300, 450, and 600 mg QD.

[0203] Patients were allowed to backfill previously cleared doses.

[0204] Intra-patient dose escalation was allowed after completion of Cycle 3.

[0205] Results (as of April 20, 2019)

[0206] Patient Population:

[0207] Forty-six patients were treated with H3B-6545 at doses ranging from 100 to 600 mg QD.

[0208] Forty-two (91.3%) patients had received prior CDK4 / 6 inhibitors, and 32 (69.6%) had received prior fulvestrant.

[0209] Thirty (65.2%) patients had received >3 prior anticancer therapy regimens in the advanced / metastatic setting.

[0210] Demographics and baseline characteristics are shown in Table 6.

[0211] Table 6

[0212]

[0213]

[0214]

[0215] a Age is age at the time of informed consent.

[0216] b If a subject had multiple sites in the same category, the subject was counted only once in that category.

[0217] Safety:

[0218] Two dose-limiting toxicities (DLTs) occurred in the 600 mg QD cohort, grade 3 fatigue and grade 3 measles-like rash.

[0219] The most common (>10%) treatment-related adverse events (TRAEs) included sinus bradycardia, nausea, fatigue, anemia, diarrhea, and aspartate aminotransferase (Table 2).

[0220] Six grade 3 TRAEs were observed: syncope and ECG QT prolongation at 450 mg; anemia, aspartate aminotransferase increase, fatigue, and measles-like skin rash at 600 mg.

[0221] No TRAEs > grade 4.

[0222] The most common TRAE (sinus bradycardia) did not present dose- or concentration- dependence and did not require dose reduction, interruption, or discontinuation.

[0223] TRAEs are summarized in Table 7.

[0224] Table 7: Treatment-related adverse events > 10%

[0225]

[0226] Pharmacokinetics:

[0227] t max was 2 to 4 h

[0228] Plasma concentrations increased with dose (100 to 600 mg). Figure 2

[0229] Plasma concentrations were similar between C1D1 and C1D15.

[0230] Pharmacodynamics:

[0231] ESR1 (55%) and PIK3CA (39%) mutations were detected in baseline plasma.

[0232] Changes in mutant allele frequency showed correlation with clinical response.

[0233] Patient case study:

[0234] A 50-year-old female patient was first diagnosed with ER+HER2- breast cancer in 2006 with a metastatic background of prior treatments including letrozole / palbociclib, entinostat / exemestane, capecitabine, eribulin, and carboplatin / gemcitabine. ESR1 Y537S and PI3KCA E545K mutations were detected in baseline tumor and plasma. At the time of enrollment, ECOG performance status was 1; disease locations included liver, bone, pleural effusion, pelvic ascites, and subcutaneous nodules. H3B-6545 was initiated at a dose of 450 mg QD in June 2018.

[0235] The sum of diameters of all target lesions decreased by -27.8% and -35.6% from baseline to C3D1 and C7D1, respectively. After 4 cycles, the patient achieved a partial response and remained on C11 treatment.

[0236] Preliminary activity: ​

[0237] Stable disease was observed in 17 (37.0%) patients

[0238] 14 (30.4%) patients completed at least 6 months of treatment

[0239] Confirmed partial response was observed in 3 (6.5%) patients

[0240] Figure 3 Further information on preliminary activity is shown. Figure 4 Percent change in the sum of diameters of target lesions is shown.

[0241] Table 8 shows tumor responses and progression-free survival.

[0242] Table 8

[0243]

[0244]

[0245] Summary

[0246] Safety / tolerability: Most TRAEs were Grade 1 or 2 and manageable; up to and including 450 mg QD was tolerated.

[0247] Pharmacodynamics: Changes in mutant allele frequency showed correlation with clinical response.

[0248] Preliminary activity: Encouraging signals of antitumor activity were observed in the context of heavily pre-treated CDK4 / 6i, including 3 confirmed partial responses and mPFS = 7.2 months.

[0249] Phase 2: To be initiated after RP2D is determined.

[0250] Example 4: Second Interim Analysis

[0251] The clinical trial of Example 3 was continued, and later PK evaluations were performed based on a larger patient population (of this Example 4). The pharmacokinetic (PK) analysis of the capsules of Table 1 in fasted patients, as well as the summary in Table 2, show the PK parameters and profiles of human patients who received capsules of the H3B-6545 drug product prepared in Example 1. As determined in the tables, patients received a total equivalent dose of 100 mg, 200 mg, 300 mg, 450 mg, or 600 mg of Formula I. Table 1 reflects the PK values of the patients measured on the first day of the first cycle. Table 2 reflects the PK values of the patients measured on the fifteenth day of the first cycle.

[0252] After administration to human subjects in need, who are fasting, the PK parameter is calculated. QD means "quaque die" or "once daily". Parameter n is the number of human subjects in need who are given the appropriate dose.

[0253] Tables 9 and 11 include, except for T max and T lag The geometric mean and coefficient of variation of all plasma PK parameters related to each dose, excluding those obtained from human subjects (n) in need. max and T lag The values ​​include the median values ​​calculated in human subjects in need, excluding the minimum and maximum values. Tables 10 and 12 normalize the AUC0-t, AUC0-24, AUC0-inf, and Cmax PK parameters shown in Tables 9 and 11 relative to the plasma PK parameters per 1 mg of active pharmaceutical ingredient (API).

[0254] Table 9

[0255]

[0256] Table 10:

[0257]

[0258] Table 11

[0259]

[0260]

[0261] Table 12

[0262]

[0263] Example 5: Pharmacokinetics (PK) of 450 mg Capsules in Fasting and Eating Patients. Table 3 details the PK parameters and curves for human patients who received the capsules prepared in Example 1. As confirmed in Table 13, patients received a total equivalent dose of Formula I of 450 mg. Table 14 normalizes the AUC0-t, AUC0-24, AUC0-inf, and Cmax PK parameters shown in Table 13 relative to the plasma PK parameters per 1 mg of the active pharmaceutical ingredient (API).

[0264] Table 13

[0265]

[0266] Table 14

[0267]

[0268] Example 6: Pharmacokinetics (PK) of tablets in humans

[0269] Capsules described in Example 1 and tablets described in Example 2 were tested in healthy human subjects. All doses were well tolerated. Similar exposure (Cmax and AUC) and Tmax of H3B-6545 between capsules and tablets were noted, as shown in Table 15.

[0270] Table 15

[0271]

[0272] The relative bioavailability of capsules versus tablet formulation of H3B-6545 is shown in Table 16.

[0273] Table 16

[0274]

[0275] Geo. LSM: Geometric least square mean.

[0276] CI: Confidence interval; * column shows lower and upper bounds.

[0277] CV: Coefficient of variation

[0278] Example 7 - Genomic study

[0279] Due to the lack of effective treatments for endocrine-resistant metastatic breast cancer (MBC), the Applicant developed H3B-6545, a novel selective ERa covalent antagonist, capable of irreversibly inactivating both wild-type and mutant Era.

[0280] The objectives of this study were 1) to characterize the hotspot mutation profile in heavily pre-treated MBC and correlate ESR1, PIK3CA and AKT1 mutations in plasma and tumor tissue; 2) to determine if mutations in ESR1 or PIK3CA predict response to H3B-6545; 3) to assess if longitudinal tracking of ctDNA correlates with response to H3B-6545.

[0281] Methods

[0282] Fresh plasma samples were collected at baseline (pre-dose), Cycle 1 Day 15 (C1D15), C2D1, C3D1 and every 8 weeks thereafter, with a last sample collection at disease progression. At baseline, hot spot mutations in ESR1, PIK3CA and AKT1 were assessed using BEAMing digital PCR. Patientspecific ctDNA mutations were subsequently monitored by ddPCR. Baseline tumor biopsies were subjected to targeted next generation sequencing (NGS) panels to identify hot spot mutations.

[0283] Results

[0284] Mutations were detected at baseline by BEAMing assay in 77% of patients (30 / 39), with 21 / 39, 16 / 39 and 3 / 39 having mutations in ESR1, PIK3CA and AKT1, respectively. 20% (9 / 39) of patients presented co-mutations in ESR1 and PIK3CA. In 60% (9 / 15) of patients, DNA mutations identified by plasma BEAMing assay were also detected in tumor biopsies; in 86% (12 / 14) of cases, DNA mutations found in tissue were also detected in plasma. Gradient ctDNA monitoring revealed that in patients with confirmed partial response (3 / 3), ctDNA levels were not detected by C2D1. In contrast, in 3 / 4 patients with disease progression, ctDNA levels increased from baseline. Explorations on ctDNA ratios (Day 15 / baseline and Day 30 / baseline) and correlation of PIK3CA and ESR1 mutations with response to H3B-6545 were shown.

[0285] Summary of Example 7

[0286] ctDNA is a reliable sample type for assessing ESR1, PIK3CA and AKT1 mutations in MBC, overcoming the challenge of obtaining biopsies in a metastatic setting. Moreover, ctDNA kinetics appeared as a useful tool to monitor the efficacy of H3B-6545.

[0287] Drug administration and dosage:

[0288] H3B-6545 was administered orally once daily (PO QD) in 28-day cycles

[0289] A standard 3+3 study design was used, with dose escalation using cohorts of 100, 200, 300, 450 and 600 mg / day.

[0290] Liquid biopsies: 10 ml of Strek plasma was collected at this site and then processed into plasma at Sysmex Inostics. cfDNA was isolated from 2 ml of plasma for BEAMing and 3 ml of plasma for Biorad ddPCR.

[0291] Tumor next generation sequencing (NGS) analysis: DNA was isolated from 10x 5 pm slides using Recoverall kit and then 10 ng of DNA was used as input for Oncomine Comprehensive assay.

[0292] Table 17 shows study baseline characteristics.

[0293] Table 17

[0294]

[0295] Figure 5 An overview of the liquid biopsy and tissue biopsy sample set is shown.

[0296] Figure 5 A ~ Figure 5 E shows the baseline genomic profile of the patients in this example. AA = amino acid. * AKT1 mutation was observed in 3 / 49 patients (data not shown).

[0297] Figure 5F A to 5E shows the BEAMing assay. A: Baseline ESR1 and PIK3CA mutational status of the patients; B and C: Monoclonality of ESR1 and PIK3CA mutations; D and E: Amino acid distribution of PIK3CA and ESR1 mutations.

[0298] Figure 6A An oncoprint plot showing mutations found in baseline tissue biopsy as determined by the Oncomine Comprehensive Panel is shown.

[0299] Figure 6B and Figure 6A An agreement of mutations found in tissue and liquid biopsies in Example 2 is shown. Figure 6B An allele frequency distribution and agreement of tissue and liquid biopsy mutations is shown. Figures 7A-7C Is a summary table of the agreement of tissue and liquid biopsy mutations.

[0300] Figure 7A An overview of ctDNA kinetics associated with overall best response to H3B-6545 is shown. AF = allele frequency, C = cycle, D = day, PD = progressive disease, PR = partial response, SD = stable disease. Dotted line represents ddPCR assay LOD.Figure 7B : Proportion of patients with AF baseline / C2D1 by individual coloration. One patient can have multiple mutations. Figure 7C and ​ : Example of ctDNA kinetics in patients with disease progression (B) versus partial response (C).

[0301] Patient Case Study - This is the same patient case study reported in Example 3.

[0302] 1 female, 50 years old, was first diagnosed with ER+ HER2- BC in 2006.

[0303] Prior treatment in metastatic setting included letrozole / palbociclib, entinostat / exemestane, capecitabine, eribulin, and carboplatin / gemcitabine.

[0304] ECOG performance status was 1 at enrollment; disease locations included liver, bone, pleural effusion, pelvic ascites, and subcutaneous nodules.

[0305] ESR1 Y537S and PI3KCA E545K mutations were detected in baseline tumor and plasma.

[0306] H3B-6545 was initiated at 450 mg PO QD in June 2018.

[0307] The sum of diameters of all target lesions decreased by -27.8% and -35.6% from baseline to C3D1 and C7D1, respectively.

[0308] After 4 cycles, the patient achieved a partial response and remained on C11 treatment.

[0309] Conclusion

[0310] In the advanced setting of ER+ MBC, PIK3CA and ESR1 mutations were detected in 39% and 55% of baseline plasma, respectively.

[0311] The concordance of tissue and plasma mutation levels was 80%.

[0312] The concordance of liquid biopsy and tissue mutation levels was 51%.

[0313] In patients with confirmed partial response, ctDNA levels were not detected by C2D1.

[0314] ctDNA kinetics emerged as a useful tool for monitoring efficacy of H3B-6545 and characterization of baseline genomic profile.

[0315] All publications and patent documents cited herein are incorporated by reference herein, as if each had been individually incorporated by reference. Publication and patent document citations are not intended to represent an admission of prior art, nor are they intended to represent a limitation on the scope of the application. The present application is described by way of written description, and it is recognized that various modifications can be made to the application, and the above description is intended to include such modifications within the scope of the application, which is defined by the appended claims.

[0316] The application can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects as illustrative only and not restrictive. The scope of the application is thus indicated by the appended claims rather than by the description, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Claims

1. An oral dosage form, wherein, The oral dosage form is a capsule comprising: i) an inner phase comprising the compound of Formula I or a pharmaceutically acceptable salt thereof, lactose monohydrate, low-substituted hydroxypropylcellulose, microcrystalline cellulose, hydroxypropylcellulose, colloidal anhydrous silica, and magnesium stearate, wherein the Formula I is (E)-N,N-dimethyl-4-[2-[5-[(Z)-4,4,4-trifluoro-1-(3-fluoro-1H- indazol-5-yl)-2-phenylbut-1-enyl]pyridin-2-yl]oxyethylamino]but-2-enamide represented by the following structure: and ii) an outer phase comprising magnesium stearate, wherein the dosage form comprises a total equivalent of 25 mg, 50 mg, or 100 mg to 600 mg of the compound of Formula I or a pharmaceutically acceptable salt thereof, and wherein the compound of Formula I or a pharmaceutically acceptable salt thereof comprises 25% to 30% of the total weight of the dosage form, the lactose monohydrate comprises 10% to 15% of the total weight of the dosage form, the low-substituted hydroxypropylcellulose comprises 5% to 10% of the total weight of the dosage form, the microcrystalline cellulose comprises 1% to 5% of the total weight of the dosage form, the hydroxypropylcellulose comprises 0.5% to 5% of the total weight of the dosage form, the colloidal anhydrous silica comprises 0.05% to 0.5% of the total weight of the dosage form, and the magnesium stearate comprises 0.1% to 1% of the total weight of the dosage form.

2. The oral dosage form of claim 1, wherein, The dosage form comprises a total equivalent of 100 mg to 600 mg of the compound of Formula I or a pharmaceutically acceptable salt thereof.

3. The oral dosage form of claim 1, wherein, The dosage form comprises a total equivalent of 450 mg of the compound of Formula I or a pharmaceutically acceptable salt thereof.

4. The oral dosage form of claim 1, wherein, The dosage form comprises 150 mg of the compound of Formula I or a pharmaceutically acceptable salt thereof.

5. The oral dosage form of claim 1, wherein, The dosage form comprises 50 mg of the compound of Formula I or a pharmaceutically acceptable salt thereof.

6. The oral dosage form of claim 1, wherein, The dosage form comprises 25 mg of the compound of Formula I or a pharmaceutically acceptable salt thereof.

7. The oral dosage form of claim 1, wherein, The oral dosage form comprises a capsule shell comprising hypromellose.

8. The oral dosage form of claim 7, wherein, The capsule shell further comprises iron oxide red and titanium dioxide.

9. The oral dosage form of claim 8, wherein, The iron oxide red comprises 0.5% to 2% of the total weight of the dosage form, and the titanium dioxide comprises 0.5% to 2% of the total weight of the dosage form.

10. An oral dosage form wherein, The oral dosage form is a capsule comprising: i) an inner phase comprising 150 mg of the compound of Formula I or 150 mg of a pharmaceutically acceptable salt of the compound of Formula I in an equivalent amount of free base, 67.74 mg of lactose monohydrate, 45 mg of low-substituted hydroxypropylcellulose, 15 mg of microcrystalline cellulose, 9.0 mg of hydroxypropylcellulose, 0.6 mg of colloidal anhydrous silica, and 1.5 mg of magnesium stearate; and ii) an outer phase comprising 1.5 mg of magnesium stearate, wherein the Formula I is (E)-N,N-dimethyl-4-[2-[5-[(Z)-4,4,4-trifluoro-1-(3-fluoro-1H- indazol-5-yl)-2-phenylbut-1-enyl]pyridin-2-yl]oxyethylamino]but-2-enamide represented by the following structure:

11. The oral dosage form of claim 10, wherein, The pharmaceutically acceptable salt is a monohydrochloride salt of the compound of Formula I.

12. The oral dosage form of claim 11, wherein, The monohydrochloride salt of the compound of Formula I is present in an amount of 159.66 mg.

13. The oral dosage form of claim 11, wherein, The dosage form comprises a hydroxypropyl methylcellulose capsule shell.

14. The oral dosage form of claim 13, wherein, The hydroxypropyl methylcellulose capsule shell comprises hydroxypropyl methylcellulose, red iron oxide, and titanium dioxide.

15. An oral dosage form, wherein, The oral dosage form is a capsule comprising: i) an inner phase comprising 50 mg of the compound of Formula I or 50 mg of the pharmaceutically acceptable salt of the compound of Formula I in free base equivalent amount, 22.58 mg of lactose monohydrate, 15 mg of low-substituted hydroxypropyl cellulose, 5.0 mg of microcrystalline cellulose, 3.0 mg of hydroxypropyl cellulose, 0.2 mg of colloidal anhydrous silica, and 0.5 mg of magnesium stearate; and ii) an outer phase comprising 0.5 mg of magnesium stearate, wherein the Formula I is (E)-N,N-dimethyl-4-[2-[5-[(Z)-4,4,4-trifluoro-1-(3-fluoro-1H- indazol-5-yl)-2-phenylbut-1-enyl]pyridin-2-yl]oxyethylamino]but-2-enamide represented by the following structure:

16. The oral dosage form of claim 15, wherein, The pharmaceutically acceptable salt is a monohydrochloride salt of the compound of Formula I.

17. The oral dosage form of claim 16, wherein, The monohydrochloride salt of the compound of Formula I is present in an amount of 53.22 mg.

18. The oral dosage form of claim 16, wherein, The dosage form comprises a hydroxypropyl methylcellulose capsule shell.

19. The oral dosage form of claim 18, wherein, The hydroxypropyl methylcellulose capsule shell comprises hydroxypropyl methylcellulose, red iron oxide, and titanium dioxide.

20. An oral dosage form, wherein, The oral dosage form is a capsule comprising: i) an inner phase comprising 25 mg of the compound of Formula I or 25 mg of the pharmaceutically acceptable salt of the compound of Formula I in free base equivalent amount, 11.29 mg of lactose monohydrate, 7.5 mg of low-substituted hydroxypropyl cellulose, 2.5 mg of microcrystalline cellulose, 1.5 mg of hydroxypropyl cellulose, 0.1 mg of colloidal anhydrous silica, and 0.25 mg of magnesium stearate; and ii) an outer phase comprising 0.25 mg of magnesium stearate, wherein the Formula I is (E)-N,N-dimethyl-4-[2-[5-[(Z)-4,4,4-trifluoro-1-(3-fluoro-1H- indazol-5-yl)-2-phenylbut-1-enyl]pyridin-2-yl]oxyethylamino]but-2-enamide represented by the following structure:

21. The oral dosage form of claim 20, wherein, The pharmaceutically acceptable salt is a monohydrochloride salt of the compound of Formula I.

22. The oral dosage form of claim 21, wherein, The monohydrochloride salt of the compound of Formula I is present in an amount of 26.61 mg.

23. The oral dosage form of claim 21, wherein, The dosage form comprises a hydroxypropyl methylcellulose capsule shell.

24. The oral dosage form of claim 23, wherein, The hydroxypropyl methylcellulose capsule shell comprises hydroxypropyl methylcellulose, red iron oxide, and titanium dioxide.

25. The oral dosage form of claim 1, comprising a monohydrochloride salt form of Formula I.

26. An oral dosage form wherein, The oral dosage form is a capsule comprising: the compound of Formula I or a pharmaceutically acceptable salt thereof, wherein the compound of Formula I or a pharmaceutically acceptable salt thereof comprises 25% to 30% of the total weight of the dosage form; lactose monohydrate, wherein the lactose monohydrate comprises 10% to 15% of the total weight of the dosage form; low-substituted hydroxypropylcellulose, wherein the low-substituted hydroxypropylcellulose comprises 5% to 10% of the total weight of the dosage form; microcrystalline cellulose, wherein the microcrystalline cellulose comprises 1% to 5% of the total weight of the dosage form; hydroxypropylcellulose, wherein the hydroxypropylcellulose comprises 0.5% to 5% of the total weight of the dosage form; colloidal anhydrous silica, wherein the colloidal anhydrous silica comprises 0.05% to 0.5% of the total weight of the dosage form; and magnesium stearate, wherein the magnesium stearate comprises 0.1% to 1% of the total weight of the dosage form, wherein the oral dosage form comprises a capsule shell, the capsule shell comprising hypromellose, iron oxide red, and titanium dioxide, wherein the hypromellose comprises 40% to 45% of the total weight of the dosage form, the iron oxide red comprises 0.5% to 2% of the total weight of the dosage form, and the titanium dioxide comprises 0.5% to 2% of the total weight of the dosage form, and wherein the Formula I is (E)-N,N-dimethyl-4-[2-[5-[(Z)-4,4,4-trifluoro-1-(3-fluoro-1H- indazol-5-yl)-2-phenylbut-1-enyl]pyridin-2-yl]oxyethylamino]but-2-enamide, represented by the following structure:

27. The oral dosage form of claim 26, wherein, the pharmaceutically acceptable salt is a monohydrochloride salt.

28. An oral dosage form wherein, the oral dosage form is a tablet, the tablet comprising: i) an inner phase comprising 150 mg of the compound of Formula I or 150 mg of a pharmaceutically acceptable salt of the compound of Formula I in free base equivalent amount, 241.2 mg of lactose monohydrate, 90 mg of low-substituted hydroxypropylcellulose, 18 mg of hypromellose, and 1.2 mg of colloidal silicon dioxide; and ii) an outer phase comprising 12 mg of magnesium stearate and 78 mg of microcrystalline cellulose, wherein the Formula I is (E)-N,N-dimethyl-4-[2-[5-[(Z)-4,4,4-trifluoro-1-(3-fluoro-1H- indazol-5-yl)-2-phenylbut-1-enyl]pyridin-2-yl]oxyethylamino]but-2-enamide, represented by the following structure: and wherein the oral dosage form comprises a film coating, the film coating comprising 30 mg of a coating agent.

29. The oral dosage form of claim 28, wherein, the oral dosage form comprises 150 mg of a monohydrochloride salt of the compound of Formula I in free base equivalent amount.

30. The oral dosage form of claim 29, wherein, the monohydrochloride salt of the compound of Formula I is present in an amount of 159.6 mg.

31. The oral dosage form of claim 28, wherein, The coating agent is 03H420000 YELLOW.

32. Use of the oral dosage form of any one of claims 1-31 in the manufacture of a medicament for treating cancer in a human subject.

33. The use of claim 32, wherein, the cancer is breast cancer.

34. The use of claim 33, wherein, the breast cancer is ERa-positive breast cancer.

35. The use of claim 34, wherein, the breast cancer expresses wild-type ERa.

36. The use of claim 34, wherein, the breast cancer expresses mutant ERa.

37. The use of claim 32, wherein, the oral dosage form is administered once daily.

38. The use of claim 32, wherein, the oral dosage form is administered to a human subject in a fasted state.

39. The use of claim 32, wherein, the oral dosage form is administered to a human subject in a fed state.

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