Lasofoxifene treatment of aromatase-resistant ER+ cancer

Abstract

The present disclosure provides a method for the treatment of estrogen receptor-positive (ER) breast cancer in patients who have progressed on aromatase inhibitors. + The present invention provides an effective amount of lasofoxifene, or a pharma- ceutically acceptable salt or functional derivative thereof, for use in a method for treating cancer. + Cancer is of particular interest: new in vitro and animal model experiments clearly show that lasofoxifene is more effective than fulvestrant (ICI) in a letrozole-inducible, AI-resistant breast tumor model (MCF-7 LTLT cells) that does not express ERα-activating mutations.

Description

[Technical field]

[0001] 1. CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 280,769, filed November 18, 2021, the disclosure of which is incorporated by reference in its entirety herein. [Background technology]

[0002] 2. Background of the invention Estrogen receptor positive (ER + Breast cancer is a cancer that expresses estrogen receptor alpha (ERα), which is encoded by the ESR1 gene. Approximately 70% of breast cancers are ERα-positive. + and are therefore treated with agents that deplete circulating estrogen levels or block estrogen signaling in cancer cells (collectively, endocrine therapy). Selective estrogen receptor modulators (SERMs), selective estrogen receptor degraders (SERDs), and aromatase inhibitors (AIs) are the major classes of endocrine therapy agents. Endocrine therapy is a method to treat ER + Endocrine therapy has led to significant improvements in outcomes for women with breast cancer. However, the effectiveness of endocrine therapy is limited by intrinsic and, importantly, acquired endocrine resistance. In response to the selective pressures imposed by endocrine therapy (particularly aromatase inhibitors), ER + Tumors have developed various evasion mechanisms. Among these is the acquisition of gain-of-function mutations in the ESR1 gene that alter the ligand-binding domain of the ERα receptor, rendering the receptor constitutively active at low or no levels of estrogen. Despite the benefits of endocrine therapy, ER + The majority of patients with IFN-α eventually develop resistance and progress. Lasofoxifene, a selective estrogen receptor modulator (SERM), has been shown to reduce ER in women with wild-type estrogen receptors, no history of breast cancer, and postmenopausal women being treated for osteoporosis. +Lasofoxifene has been shown to reduce the risk of breast cancer. LaCroix et al., J. Natl. Cancer Inst. 102:1706-1715 (2010). Lasofoxifene inhibits ERα receptors that have a gain-of-function mutation in the ligand-binding domain of the ERα receptor. + It was later shown to retain the ability to inhibit cancer progression. U.S. Patent Nos. 10,258,605; 10,905,659; and WO2019 / 199891. + The efficacy of lasofoxifene as a single agent in treating pre- and postmenopausal women with breast cancer is currently being confirmed in a Phase 2 clinical trial, NCT03781063 (ELAINE Clinical Trial). A clinical trial confirming the efficacy of lasofoxifene in combination with the CDK4 / 6 inhibitor, abemaciclib, is also ongoing in a similar population of breast cancer patients, all of whom have gain-of-function mutations in the ERα receptor (NCT04432454 (ELAINE II Clinical Trial)). Lasofoxifene improves ER progression under endocrine therapy through acquisition of ESR1 gain-of-function mutations + It has been shown to be effective in inhibiting the progression of breast cancer, but + Cancer cells develop other mechanisms to evade endocrine therapy. Thus, ER tumors that progress under endocrine therapy and lack the ESR1 gene mutation + There remains a need for therapeutic agents that are effective in inhibiting cancer progression and metastasis. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 10,258,605 [Patent Document 2] U.S. Pat. No. 10,905,659 [Patent Document 3] International Publication No. 2019 / 199891 [Non-patent literature]

[0004] [Non-Patent Document 1] LaCroix et al., J. Natl. Cancer Inst. 102:1706-1715 (2010) Summary of the Invention [Means for solving the problem]

[0005] 3. Summary of the Invention New in vitro and animal model experiments clearly demonstrate that lasofoxifene is more effective than fulvestrant (ICI) in a letrozole-inducible, AI-resistant breast tumor model (MCF-7 LTLT cells) that does not express ERα-activating mutations. These data support the conclusion that lasofoxifene is more effective than fulvestrant (ICI) in an AI-resistant ER tumor model that does not express ERα-activating mutations. + This clearly demonstrates that it is an effective treatment for cancer.

[0006] Thus, in the first aspect, estrogen receptor positive (ER) tumors were identified in patients who had progressed on aromatase inhibitors. + ) A method for reducing the progression of cancer, wherein the cancer does not have a gain-of-function missense mutation in the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene, comprising administering to the patient an effective amount of lasofoxifene, or a pharma- ceutically acceptable salt, prodrug, or functional derivative thereof.

[0007] In some embodiments, the ER + The cancer is locally advanced or metastatic breast cancer, optionally wherein said cancer is HER2-.

[0008] In some embodiments, the aromatase inhibitor is exemestane (Aromasin®), letrozole (Femara®), or anastrozole (Arimidex®).

[0009] In some embodiments, the method further comprises the earlier step of determining that the cancer does not have a gain-of-function missense mutation within the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene.

[0010] In some embodiments, lasofoxifene is administered as lasofoxifene tartrate.

[0011] In some embodiments, lasofoxifene is administered orally, intravenously, transdermally, topically in the vagina, or by vaginal ring administration.

[0012] In some embodiments, lasofoxifene is administered by oral administration. In certain of these embodiments, lasofoxifene is administered orally at a dose of 5 mg / day to about 10 mg / day.

[0013] In some embodiments, the method further comprises treating the patient with at least one additional endocrine therapy.

[0014] In some embodiments, the method further comprises administering an effective amount of a cyclin-dependent kinase 4 / 6 (CDK4 / 6) inhibitor. In certain embodiments, the CDK4 / 6 inhibitor is palbociclib, abemaciclib, or ribociclib. In some embodiments, the CDK4 / 6 inhibitor is abemaciclib.

[0015] In some embodiments, the methods include administering an effective amount of an AKT inhibitor. In certain embodiments, the AKT inhibitor is afuresertib.

[0016] In some embodiments, the method further comprises administering an effective amount of an mTor inhibitor.

[0017] 4. Brief description of the drawings These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description and accompanying drawings. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 shows a comparison of variant counts in the AI-resistant breast tumor model MCF-7 LTLT cells against two publicly available reference genomes of MCF7 “WT” from the literature.

[0019] [Diagram 2] Figure 2 presents data showing that lasofoxifene inhibits primary tumor growth of MCF7 LTLT (AI-resistant ER+ cells lacking ESR1 gain-of-function mutations) tumors. Data are from in vivo imaging showing total photon flux quantified with Live Image software over time for each group. Mice were treated with vehicle, palbociclib, lasofoxifene, fulvestrant (ICI), lasofoxifene + palbociclib, or fulvestrant (ICI) + palbociclib.

[0020] [Diagram 3] Figure 3 is a histogram summarizing data showing that lasofoxifene inhibits primary tumor growth in AI-resistant ER+ cells lacking ESR1 gain-of-function mutations. The histogram shows total photon flux in mammary glands at day 104. N=6-12 glands ± SEM. P values ​​are *p<0.05, **p<0.005, ***p<0.0005, ****p<0.0001.

[0021] [Figure 4] Figure 4 shows data demonstrating that lasofoxifene inhibits the increase in primary tumor weight in AI-resistant ER+ cells lacking ESR1 gain-of-function mutations. The histogram shows the mean weight of mammary glands on the day of sacrifice. N=6-12 glands ± SEM. P values ​​are *p<0.05, **p<0.005, ***p<0.0005, ****p<0.0001.

[0022] [Diagram 5] Figure 5 shows data demonstrating that tumor area is reduced by lasofoxifene and lasofoxifene + palbociclib. Percent tumor area versus total gland area as revealed via H&E analysis of cut sections of mammary glands. Histograms showing percent tumor area relative to total gland area of ​​H&E sections. N=3-6 glands ± SEM. P values ​​are *p<0.05, **p<0.005, ***p<0.0005, ****p<0.0001.

[0023] [Figure 6-1] FIG. 6 shows data demonstrating that lasofoxifene reduces the Ki67 proliferation index as a single agent and in combination with palbociclib in the Let+ cohort. FIG. 6A shows % Ki67 in the comparison of vehicle vs. Let- vs. Let+ cohorts. FIG. 6B and FIG. 6C show % Ki67 in the Let- and Let+ cohorts, respectively. N=3-6 glands ± SEM. P values ​​are *p<0.05, **p<0.005, ***p<0.0005, ****p<0.0001. [Figure 6-2] Same as above.

[0024] [Figure 7A] Figure 7 shows ex vivo radiance measurements in liver, lungs and brain. Ex vivo imaging of organs excised at the time of sacrifice. Radiance was measured in liver (Figure 7A), lungs (Figure 7B), and brain (Figure 7C). N=3-6 for liver, lungs and brain, and N=6-12 for bone. [Figure 7B] Same as above. [Figure 7C] Same as above.

[0025] [Figure 8] Figure 8 shows ex vivo radiance measurements in bones. Figure 8A: Radiance was measured in bones at the time of sacrifice. N=6-12 for bones. Figure 8B shows a representative image.

[0026] [Figure 9-1] Figure 9 shows data indicating that ERα and glucocorticoid receptor (GR) protein expression is lower in MCF7aro and LTLT compared to MCF7 and T47D. Figure 9A, Western blot showing ERα and actin. Figure 9B, Normalization of ERα levels to actin. Figure 9C, Western blot showing GR and actin. Figure 9D, Normalization of GR protein bands to actin. [Figure 9-2] Same as above.

[0027] [Figure 10-1] Figure 10 shows data comparing AR, HER2 and PR protein levels in MCF7aro and MCF7 LTLT compared to MCF7 and T47D. Figure 10A, Western blot showing AR and actin. Figure 10B, Normalization of AR levels to actin. Figure 10C, Western blot showing Her2 expression in MCF7 LTLT. Figure 10D, Normalization of Her2 to actin for T47D and MCF7 LTLT. Figure 10E, Western blot showing PR. For AR and Her2, one gel was run. For PR, one of two representative experiments is shown. [Figure 10-2] Same as above. [Figure 10-3] Same as above. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] 5. Detailed Description of the Invention Estrogen receptor positive (ERα +Postmenopausal patients with primary invasive breast cancer are typically treated with aromatase inhibitors (AIs) as first-line adjuvant therapy. Patients who become resistant to AIs are currently treated with SERDs, fulvestrant, and / or CDK4 / 6 inhibitors (e.g., palbociclib) as second-line therapy. Lasofoxifene has previously been used to treat ERα receptors that have become resistant to AIs through the acquisition of gain-of-function (activating) mutations in the ligand-binding domain of the ERα receptor. + It has been shown clearly to retain its ability to inhibit tumor progression. + The ability of lasofoxifene to prevent the progression of cancer is unknown.

[0029] As described in the following examples, the present inventors compared the efficacy of lasofoxifene (both alone and in combination with palbociclib) to fulvestrant (both alone and in combination with palbociclib) in a breast tumor model using letrozole-inducible AI-resistant cells (LTLT cells) that do not have activating mutations in the ligand-binding domain of ERα.Lasofoxifene (both alone and in combination with palbociclib) was significantly more effective than fulvestrant (both alone and in combination with palbociclib) in inhibiting primary tumor growth.In addition, all treatments except fulvestrant alone inhibited bone metastasis relative to vehicle.These data show that lasofoxifene is more effective than fulvestrant in this tumor model, clearly indicating that lasofoxifene is an effective treatment for AI-resistant breast cancer that does not express ERα activating mutations. The data indicate that the combination of lasofoxifene and a cyclin-dependent kinase 4 / 6 (CDK4 / 6) inhibitor is a more effective treatment for AI-resistant breast cancers that do not express ERα-activating mutations. Furthermore, lasofoxifene (alone or in combination with a cyclin-dependent kinase 4 / 6 (CDK4 / 6) inhibitor) inhibits metastases to bone and to the brain.

[0030] 5.1. Treatment method Thus, in the first aspect, estrogen receptor positive (ER) tumors were identified in patients who had progressed on aromatase inhibitors. + Disclosed herein is a method of reducing the progression of a cancer, wherein the cancer does not have a gain-of-function missense mutation in the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene, comprising administering to the patient an effective amount of lasofoxifene, or a pharma- ceutically acceptable salt, prodrug, or functional derivative thereof.

[0031] In some embodiments, the method further comprises the earlier step of determining that the cancer does not have a gain-of-function missense mutation within the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene.

[0032] The method includes administering an effective amount of lasofoxifene, or a pharma- ceutically acceptable salt, prodrug, or functional derivative thereof, in combination with a cyclin-dependent kinase 4 / 6 (CDK4 / 6) inhibitor (e.g., palbociclib, abemaciclib, or ribociclib), and / or an aromatase inhibitor (e.g., exemestane (aromasin), (登録商標) ), Letrozole (Femara (登録商標) ), or anastrozole (Arimidex (登録商標) ) to the patient.

[0033] 5.1.1 ER + Patients with cancer In various embodiments, the patient is +The patient is diagnosed with cancer. In some embodiments, the ER status is determined by immunohistochemistry (IHC), RT-PCR, massively parallel next-generation sequencing (NGS), or other conventional techniques performed on the patient's cancer sample. In some embodiments, the sample is tumor tissue from a biopsy. In some embodiments, the sample is a liquid biopsy from blood, saliva, or other bodily fluids (e.g., serum, circulating DNA of tumor biomarkers).

[0034] In some embodiments, the patient is + In some embodiments, the cancer is ER. + / HER2 - In some embodiments, the patient has breast cancer. + In some embodiments, the cancer is locally advanced or metastatic ER cancer. + In some embodiments, the patient has previously received exemestane (Aromasin). (登録商標) ), Letrozole (Femara (登録商標) ), or anastrozole (Arimidex (登録商標) ).

[0035] In some embodiments, the patient is premenopausal, peri-menopausal, or post-menopausal. + In some embodiments, the patient is premenopausal and has locally advanced or metastatic ER cancer. + In some embodiments, the patient is peri-menopausal and has primary ER. + In some embodiments, the patient is peri-menopausal and has locally advanced or metastatic ER cancer. + In some embodiments, the patient is postmenopausal and has primary ER cancer. +In some embodiments, the patient is postmenopausal and has locally advanced or metastatic ER cancer. + Having breast cancer.

[0036] In some embodiments, the patient is premenopausal and has primary breast cancer or locally advanced or metastatic ER. + Patients with breast cancer who have been previously treated with an aromatase inhibitor in combination with a second therapy, such as goserelin (Zoladex), (登録商標) ) or leuprolide (Leuprolide (登録商標) ), may have been treated with letrozole in combination with

[0037] In some embodiments, the patient has ER other than breast cancer. + In some of these embodiments, the patient has been diagnosed with ER cancer. + In some of these embodiments, the patient has been diagnosed with ovarian cancer. + She has been diagnosed with lung cancer. In certain embodiments, the cancer is a gynecological cancer selected from uterine, cervical, peritoneal, vulvar, and vaginal cancer.

[0038] In some embodiments, the patient has primary ER. + Diagnosed with uterine cancer. In certain embodiments, the uterine cancer is selected from endometrioid, clear cell carcinoma, papillary serous, carcinosarcoma, leiomyosarcoma, and endometrial stromal sarcoma (ESS). In certain embodiments, the uterine cancer is endometrial stromal sarcoma, endometrial adenosarcoma, uterine adenosquamous carcinoma, uterine leiomyosarcoma, or endometrial carcinoma.

[0039] In some of these embodiments, the patient is + The patient has been diagnosed with cervical cancer. In certain embodiments, the cervical cancer is clear cell carcinoma of the cervix.

[0040] In some of these embodiments, the patient is + Diagnosed with vulvar / vaginal cancer. In certain embodiments, the vulvar or vaginal cancer is squamous cell carcinoma (SCC) or adenocarcinoma.

[0041] In some of these embodiments, the patient is + The patient has been diagnosed with lung cancer. In certain embodiments, the lung cancer is lung adenosarcoma, lung squamous cell carcinoma, or small cell lung carcinoma.

[0042] In certain embodiments, the cancer is a cancer of the digestive system selected from esophageal cancer, gastric cancer, small intestine cancer, colon cancer, rectal cancer, and colorectal cancer.

[0043] In some embodiments, the patient has primary ER. + The patient has been diagnosed with esophageal cancer. In certain embodiments, the esophageal cancer is an adenocarcinoma or squamous cell carcinoma.

[0044] In some embodiments, the patient has primary ER. + The patient has been diagnosed with gastric cancer. In certain embodiments, the gastric cancer is gastric adenocarcinoma.

[0045] In some embodiments, the patient has primary ER. + The patient is diagnosed with small intestine cancer. In certain embodiments, the small intestine cancer is an adenocarcinoma, a carcinoid tumor, a lymphoma, or a sarcoma (e.g., leiomyosarcoma). In certain embodiments, the small intestine cancer is a malignant small intestine neoplasm.

[0046] In some embodiments, the patient has primary ER. + The patient has been diagnosed with colon cancer. In certain embodiments, the colon cancer is colon adenocarcinoma.

[0047] In some embodiments, the patient has primary ER. +Has been diagnosed with rectal cancer. In certain embodiments, the rectal cancer is rectal adenocarcinoma.

[0048] In some embodiments, the patient has primary ER. + The patient has been diagnosed with colorectal cancer. In certain embodiments, the colorectal cancer is colorectal adenocarcinoma and colorectal mucinous adenocarcinoma.

[0049] In certain embodiments, the cancer is selected from bladder cancer, e.g., bladder urothelial carcinoma; glioblastoma, e.g., conventional glioblastoma multiforme; skin cancer, e.g., cutaneous squamous cell carcinoma; melanoma, e.g., cutaneous melanoma; invasive renal pelvis cancer; pancreatic cancer, e.g., pancreatic adenocarcinoma, and cancer of unknown primary origin.

[0050] In some embodiments, the ER + The cancer is a primary cancer. + The cancer is a localized cancer. In some embodiments, the cancer is locally advanced. In some embodiments, the cancer is metastatic ER cancer. + It's cancer.

[0051] In some embodiments, the patient's cancer has relapsed or progressed after tamoxifen treatment. In some embodiments, the patient's cancer has relapsed or progressed after fulvestrant treatment. In some embodiments, the patient's cancer has relapsed or progressed after aromatase inhibitor treatment. In some of these embodiments, the patient's cancer has relapsed or progressed after multiple lines of endocrine therapy treatment.

[0052] Detection of ESR1 gene mutations In various embodiments, the patient is pre-determined not to have a mutation in the LBD of the ESR1 gene. Some embodiments of the methods described herein further comprise detecting a mutation in the ESR1 gene.

[0053] In some embodiments, massively parallel next-generation sequencing (NGS) is used to detect estrogen receptor mutations in the patient's cancer. In certain embodiments, the entire genome is sequenced. In certain embodiments, a selected gene panel of cancer-related genes is sequenced. In certain embodiments, all coding exons in a given gene set are sequenced. In certain embodiments, known "hotspot" regions in a given gene set are sequenced. However, the inherent error rate of current next-generation sequencing technology is up to 1%, limiting detection sensitivity and detection specificity. In some embodiments, targeted sequencing is used to detect the presence of ESR1 mutations. Although targeted sequencing allows for deeper sequencing, it is also currently limited by an error rate of 1%. In some embodiments, a method with reduced sequencing error rate is used. In certain embodiments, the Safe-Sequencing System (Safe-SeqS) is used. It tags each template molecule to enable reliable identification of rare variants. See Kinde et al., Proceedings of the National Academy of Sciences 108(23):9530-9535 (2011). In certain embodiments, ultrasensitive duplex sequencing is used, which independently tags and sequences each of the two strands of a DNA duplex. See Schmitt et al., Proceedings of the National Academy of Sciences 109(36):14508-14513 (2012). In some embodiments, digital droplet PCR is used, which emulsifies DNA into thousands to millions of droplets to encapsulate single DNA molecules that are designed with mutant-specific primers.See Vogelstein and Kinzler, Proceedings of the National Academy of Sciences 96(16):2322-2326 (1999) and Huggett et al., Clinical Chemistry 61(1):79-88 (2014).

[0054] In some embodiments, the detection of the ESR1 mutation is performed at the time of initial diagnosis. In some embodiments, the detection of the mutation is performed at the time of disease progression, relapse, or recurrence. In some embodiments, the detection of the mutation is performed at the time of disease progression. In some embodiments, the detection of the mutation is performed when the disease is stable.

[0055] In some embodiments, one or more tissue specimens are obtained for detection of the mutation. In certain embodiments, the tissue specimen is a tumor biopsy. In certain embodiments, the tissue specimen is a metastasis biopsy. In some other embodiments, a liquid biopsy is obtained for detection of the mutation. In certain embodiments, the liquid biopsy is a circulating tumor cell (CTC). In certain other embodiments, the liquid biopsy is cell-free DNA from a blood sample.

[0056] In a specific embodiment, the ESR1 mutation is monitored by circulating tumor DNA (ctDNA) analysis. In some embodiments, the ctDNA analysis is performed throughout the treatment course. In some of these embodiments, the ctDNA is extracted from patient blood samples. In certain embodiments, the ctDNA is evaluated by digital PCR analysis of the ESR1 mutation.

[0057] 5.1.2. Supportive measures In various embodiments, lasofoxifene is administered to the patient as adjunctive treatment. In certain embodiments, lasofoxifene is administered to the patient alone as adjunctive treatment. In certain other embodiments, lasofoxifene is administered to the patient as adjunctive treatment in combination with other endocrine therapies. In some embodiments, lasofoxifene is administered to the patient after primary treatment. In some of these embodiments, lasofoxifene is administered to the patient after surgical removal or debulking of cancer.

[0058] In some embodiments, lasofoxifene is administered to the patient as adjunctive therapy in combination with an aromatase inhibitor (AI). In various embodiments, the aromatase inhibitor is exemestane (Aromasin). (登録商標) ), Letrozole (Femara (登録商標) ), or anastrozole (Arimidex (登録商標) ).

[0059] In various embodiments, the aromatase inhibitor predisposes the patient to bone-related toxic effects. In some embodiments, the aromatase inhibitor predisposes the patient to osteoporosis. In some embodiments, the aromatase inhibitor predisposes the patient to bone loss. In some embodiments, the aromatase inhibitor predisposes the patient to bone fractures. In some embodiments, the aromatase inhibitor predisposes the patient to bone pain.

[0060] In various embodiments, the aromatase inhibitor predisposes the patient to vulvovaginal atrophy (VVA).

[0061] In some embodiments, lasofoxifene is administered continuously during administration of the aromatase inhibitor. In some other embodiments, lasofoxifene is administered periodically during administration of the aromatase inhibitor. In some embodiments, lasofoxifene and the aromatase inhibitor are administered together (concurrently). In some other embodiments, lasofoxifene and the aromatase inhibitor are administered separately (sequentially).

[0062] In certain embodiments, the dosing regimen of lasofoxifene is different from the dosing regimen of the aromatase inhibitor. In some of these embodiments, the dosage of lasofoxifene is different from the dosage of the aromatase inhibitor. In some embodiments, the dosing schedule of lasofoxifene is different from the dosing schedule of the aromatase inhibitor. In some embodiments, the route of administration of lasofoxifene is different from the route of administration of the aromatase inhibitor.

[0063] In certain embodiments, the dosage regimen of lasofoxifene is the same as the dosage regimen of the aromatase inhibitor. In some embodiments, the dosage amount of lasofoxifene is the same as the dosage amount of the aromatase inhibitor. In some embodiments, the dosage schedule of lasofoxifene is the same as the dosage schedule of the aromatase inhibitor. In some embodiments, the administration route of lasofoxifene is the same as the administration route of the aromatase inhibitor.

[0064] In some embodiments, lasofoxifene is administered to the patient in combination with an aromatase inhibitor as adjunctive therapy for one year. In some embodiments, lasofoxifene is administered to the patient in combination with an aromatase inhibitor as adjunctive therapy for two years. In some embodiments, lasofoxifene is administered to the patient in combination with an aromatase inhibitor as adjunctive therapy for three years. In some embodiments, lasofoxifene is administered to the patient in combination with an aromatase inhibitor as adjunctive therapy for four years. In some embodiments, lasofoxifene is administered to the patient in combination with an aromatase inhibitor as adjunctive therapy for five years. In some embodiments, lasofoxifene is administered to the patient in combination with an aromatase inhibitor as adjunctive therapy for six years. In some embodiments, lasofoxifene is administered to the patient in combination with an aromatase inhibitor as adjunctive therapy for seven years. In some embodiments, lasofoxifene is administered to the patient as adjunctive therapy in combination with an aromatase inhibitor for 8 years. In some embodiments, lasofoxifene is administered to the patient as adjunctive therapy in combination with an aromatase inhibitor for 9 years. In some embodiments, lasofoxifene is administered to the patient as adjunctive therapy in combination with an aromatase inhibitor for 10 years. In some other embodiments, lasofoxifene is administered to the patient as adjunctive therapy in combination with an aromatase inhibitor for more than 10 years. In certain embodiments, lasofoxifene is administered to the patient as adjunctive therapy in combination with an aromatase inhibitor until the patient's cancer progresses under treatment.

[0065] In some embodiments, lasofoxifene is administered in combination with an aromatase inhibitor as an adjuvant therapy to increase disease-free survival in cancer patients. In some embodiments, lasofoxifene is administered in combination with an aromatase inhibitor as an adjuvant therapy to reduce the incidence of contralateral breast cancer. In some embodiments, lasofoxifene is administered in combination with an aromatase inhibitor as an adjuvant therapy to prevent cancer recurrence or progression.

[0066] 5.2. Lasofoxifene In various embodiments, the selected patient is treated with an effective amount of lasofoxifene, a pharma- ceutically acceptable salt thereof, a prodrug or a functional derivative thereof. Lasofoxifene has the following structure: [ka]

[0067] In some embodiments, lasofoxifene is administered to the selected patient as lasofoxifene tartrate.

[0068] The term "pharmaceutically acceptable salts" refers to non-toxic pharmaceutically acceptable salts. See Gould, International Journal of Pharmaceutics 33: 201-217 (1986) and Berge et al., Journal of Pharmaceutical Sciences 66(1):1-19 (1977). However, other salts known to those skilled in the art may be used. Representative organic or inorganic acids include, but are not limited to, hydrochloric acid, hydrobromic acid, hydroiodic acid, perchloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, propionic acid, glycolic acid, lactic acid, succinic acid, maleic acid, fumaric acid, malic acid, tartaric acid, citric acid, benzoic acid, mandelic acid, methanesulfonic acid, hydroxyethanesulfonic acid, benzenesulfonic acid, oxalic acid, pamoic acid, 2-naphthalenesulfonic acid, p-toluenesulfonic acid, cyclohexanesulfamic acid, salicylic acid, saccharic acid, or trifluoroacetic acid. Representative organic or inorganic bases include, but are not limited to, basic or cationic salts such as benzathine, chloroprocaine, choline, diethanolamine, ethylenediamine, meglumine, procaine, aluminum, calcium, lithium, magnesium, potassium, sodium, and zinc.

[0069] The embodiments also include prodrugs of the compounds disclosed herein. In general, such prodrugs include functional derivatives of the compounds described herein that can be easily converted in vivo into the required compound. Thus, in the treatment method of the present invention, the term "administering" is intended to include the treatment of various disorders described with a specifically disclosed compound or a compound that may not be specifically disclosed, but that converts to a specific compound in vivo after administration to a subject. Conventional procedures for the selection and preparation of suitable prodrug derivatives are described, for example, in "Design of Prodrugs", H. Bundgaard, Elsevier, 1985.

[0070] In certain embodiments, the functional derivative of lasofoxifene includes a proteolysis targeting chimera (PROTAC) that contains lasofoxifene.In certain embodiments, PROTAC is a heterobifunctional small molecule that has three chemical components: lasofoxifene, a ubiquitin ligand binding moiety or ULM group, and a ligand for conjugating these two components.In some embodiments, lasofoxifene is covalently conjugated to the ubiquitin ligand binding moiety or ULM group via a linker. Non-limiting examples of such linkers include ester linkers, amide linkers, maleimide or maleimide-based linkers; valine-citrulline linkers; hydrazone linkers; N-succinimidyl-4-(2-pyridyldithio)butyrate (SPDB) linkers; succinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC) linkers; vinylsulfone-based linkers; linkers comprising polyethylene glycol (PEG) (e.g., but not limited to, tetraethylene glycol); linkers comprising propanols acid; linkers comprising caproleic acid, and linkers comprising any combination thereof. In an embodiment, the linker is a chemically labile linker (e.g., an acid-cleavable linker that is stable at neutral pH (bloodstream pH 7.3-7.5) but undergoes hydrolysis upon internalization into the mildly acidic endosomes (pH 5.0-6.5) and lysosomes (pH 4.5-5.0) of target cells (e.g., cancer cells). Chemically labile linkers include, but are not limited to, hydrazone-based linkers, oxime-based linkers, carbonate-based linkers, ester-based linkers, and the like.In some embodiments, the linker is an enzyme-labile linker (e.g., an enzyme-labile linker that is stable in the bloodstream but is enzymatically cleaved by, for example, lysosomal proteases (e.g., cathepsin or plasmin) in the lysosomes of the target cell (e.g., cancer cell) upon internalization into the target cell). Enzyme-labile linkers include, but are not limited to, linkers that contain peptide bonds, such as dipeptide-based linkers (e.g., valine-citrulline linkers (e.g., maleimidocaproyl-valine-citrulline-p-aminobenzyl (MC-vc-PAB) linker, valyl-alanyl-para-aminobenzyloxy (Val-Ala-PAB) linker, etc.). Chemically labile linkers, enzyme-labile, and non-cleavable linkers are described in detail, for example, in Ducry & Stump (2010) Bioconjugate Chem. 21:5-13. In certain embodiments, the ULM is selected from the group consisting of: [ka] [ka] wherein the ULM group is covalently attached to a linker to which lasofoxifene, or a pharma- ceutically acceptable salt, stereoisomer, solvate, polymorph or prodrug thereof, is attached.

[0071] Some of the crystalline forms of the compounds may exist as polymorphs and are therefore intended to be encompassed by the present invention. Additionally, some of the compounds may form solvates with water (i.e., hydrates) or common organic solvents, and such solvates are intended to be encompassed by some embodiments.

[0072] When the process for the preparation of the compounds as disclosed herein results in a mixture of stereoisomers, these isomers can be separated by conventional techniques (e.g., preparative chromatography). The compounds can be prepared in racemic form or as individual enantiomers or diastereomers, either by stereospecific synthesis or resolution. The compounds can be resolved into their component enantiomers or diastereomers, for example, by standard techniques (e.g., salt formation with an optically active base, followed by fractional crystallization and regeneration of the free acid to form stereoisomeric pairs). The compounds can also be resolved by the formation of stereoisomeric esters or amides, followed by chromatographic separation and removal of the chiral auxiliary. Alternatively, the compounds can be resolved using a chiral HPLC column. It should be understood that all stereoisomers, racemic mixtures, diastereomers, cis-trans isomers, and enantiomers thereof are encompassed by some embodiments.

[0073] Pharmaceutical Compositions Estrogen receptor positive (ER + ) A method for the treatment of cancer comprises administering a therapeutically effective amount of lasofoxifene, a pharma- ceutically acceptable salt, prodrug, or functional derivative thereof. The lasofoxifene, pharma- ceutically acceptable salt, or prodrug of the present invention may be formulated into a pharmaceutical composition. In addition to lasofoxifene, a pharma- ceutically acceptable salt, or prodrug thereof, the composition may further comprise a pharma- cetically acceptable excipient, carrier, buffer, stabilizer, or other material well known to those skilled in the art. Such materials should be non-toxic and should not interfere with the efficacy of the active ingredient. The precise nature of the carrier or other material may depend on the route of administration, e.g., oral, intravenous, transdermal, vaginal topical, or vaginal ring.

[0074] The pharmaceutical composition for oral administration can be in the form of tablet, capsule, powder or liquid. Tablet can contain solid carrier (such as gelatin or adjuvant). Liquid pharmaceutical composition generally contains liquid carrier such as water, petroleum, animal oil, vegetable oil, mineral oil or synthetic oil. Physiological salt solution, dextrose or other saccharide solution or glycol (such as ethylene glycol, propylene glycol or polyethylene glycol) can also be included.

[0075] For parenteral administration, the lasofoxifene is in the form of a parenterally acceptable aqueous solution that is pyrogen-free and has suitable pH, isotonicity and stability.Those skilled in the art can fully prepare suitable solutions using, for example, isotonic vehicles (e.g., sodium chloride injection, Ringer's injection, lactose-added Ringer's injection).Preservatives, stabilizers, buffers, antioxidants and / or other additives can be included if necessary.

[0076] Pharmaceutical compositions for topical vaginal administration can be in the form of ointments, creams, gels or lotions.Pharmaceutical compositions for topical vaginal administration often contain water, alcohol, animal oil, vegetable oil, mineral oil or synthetic oil.Hydrocarbons (paraffin), wool fat, beeswax, macrogol, emulsifying wax or cetrimide can also be included.

[0077] The compositions may be administered alone or in combination with other treatments, either simultaneously or sequentially, depending on the condition being treated.

[0078] 5.4. Treatment regimen ER +In the method of administering an effective amount of lasofoxifene, a pharma- ceutically acceptable salt, prodrug, or functional derivative thereof in the form of a pharmaceutical composition as described above for the treatment of cancer, the terms "treatment", "treating" and the like are used herein to generally mean obtaining a desired pharmacological and / or physiological effect. The effect may be prophylactic, in terms of completely or partially preventing a disease, condition, or symptom thereof, and / or therapeutic, in terms of partially or completely treating a disease or condition and / or adverse effects (e.g., symptoms that may be caused by the disease or condition). "Treatment", as used herein, encompasses any treatment of a mammalian, particularly a human, disease or condition, including (a) preventing the disease or condition from occurring in a subject who may be predisposed to, but has not yet been diagnosed as having, the disease or condition; (b) inhibiting the disease or condition (e.g., halting its development); or (c) alleviating the disease or condition (e.g., causing regression of the disease or condition, providing improvement in one or more symptoms). Improvement in any condition can be readily assessed according to standard methods and techniques known in the art. The population of subjects whose diseases are to be treated by the methods includes subjects suffering from an undesirable condition or disease, and subjects at risk of developing the condition or disease.

[0079] The term "effective amount" refers to a dosage that produces the desired effect and is administered thereto. The exact dosage will depend on the purpose of the treatment and can be ascertained by one skilled in the art using known techniques. See Lloyd, The Art, Science and Technology of Pharmaceutical Compounding (1999).

[0080] Route of Administration In various embodiments, lasofoxifene, a pharma- ceutically acceptable salt, prodrug, or functional derivative thereof is administered orally, intravenously, transdermally, topically, or by vaginal ring administration.

[0081] In some embodiments, lasofoxifene is administered to the patient by oral administration. In certain embodiments, lasofoxifene is administered orally at about 5 mg / day to about 10 mg / day, for example, in some embodiments, lasofoxifene is administered orally at about 5 mg / day. In some embodiments, lasofoxifene is administered orally at about 6 mg / day. In some embodiments, lasofoxifene is administered orally at about 7 mg / day. In some embodiments, lasofoxifene is administered orally at about 8 mg / day. In some embodiments, lasofoxifene is administered orally at about 9 mg / day. In some embodiments, lasofoxifene is administered orally at about 10 mg / day. In some embodiments, lasofoxifene is administered at a dose of about 0.5 mg / day orally to about 10 mg / day orally (e.g., about 0.5 mg / day orally to about 5 mg / day orally, about 1 mg / day orally to about 5 mg / day orally, about 2 mg / day orally to about 5 mg / day orally, about 3 mg / day orally to about 5 mg / day orally, about 4 mg / day orally to about 5 mg / day orally, about 0.5 mg / day orally to about 4 mg / day orally, about 1 mg / day orally to about 4 mg / day orally, about 2 mg / day orally to about 4 mg / day orally, about 3 mg / day orally to about 4 mg / day orally, about 0.5 mg / day orally to about 3 mg / day orally, about 1 mg / day orally to about 3 mg / day orally, about 2 mg / day orally to about 3 mg / day orally, about 0.5 mg / day orally to about 2 mg / day orally The lasofoxifene is administered to the patient by oral administration (oral) at a dosage of about 1 mg / day orally, about 1 mg / day orally to about 2 mg / day orally, or about 0.5 mg / day orally to about 1 mg / day orally. In some embodiments, lasofoxifene is administered at about 0.5 mg / day orally. In some embodiments, lasofoxifene is administered at about 1 mg / day orally. In some embodiments, lasofoxifene is administered at about 1.5 mg / day orally. In some embodiments, lasofoxifene is administered at about 2 mg / day orally. In some embodiments, lasofoxifene is administered at about 2.5 mg / day orally. In some embodiments, lasofoxifene is administered at about 3 mg / day orally.In some embodiments, lasofoxifene is administered orally at about 3.5 mg / day. In some embodiments, lasofoxifene is administered orally at about 4 mg / day. In some embodiments, lasofoxifene is administered orally at about 4.5 mg / day. In some embodiments, lasofoxifene is administered orally at about 5 mg / day. In some embodiments, lasofoxifene is administered orally at about 6 mg / day. In some embodiments, lasofoxifene is administered orally at about 7 mg / day. In some embodiments, lasofoxifene is administered orally at about 8 mg / day. In some embodiments, lasofoxifene is administered orally at about 9 mg / day. In some embodiments, lasofoxifene is administered orally at about 10 mg / day. In some other embodiments, lasofoxifene is administered orally at more than 10 mg / day. In some embodiments, lasofoxifene is administered at about 0.5 mg / day to about 10 mg / day. In some embodiments, lasofoxifene is administered at about 0.5 mg / day, about 1 mg / day, about 1.5 mg / day, about 2 mg / day, about 2.5 mg / day, about 3 mg / day, about 3.5 mg / day, about 4 mg / day, about 5 mg / day, about 5.5 mg / day, about 6 mg / day, about 6.5 mg / day, about 7 mg / day, about 7.5 mg / day, about 8 mg / day, about 8.5 mg / day, about 9 mg / day, about 9.5 mg / day, or about 10 mg / day. In some embodiments, lasofoxifene is administered orally at about 5 mg / day.

[0082] In certain embodiments, lasofoxifene is administered once every day. In certain embodiments, lasofoxifene is administered once every 2 days. In certain embodiments, lasofoxifene is administered once every 3 days. In certain embodiments, lasofoxifene is administered once every 4 days. In certain embodiments, lasofoxifene is administered once every 5 days. In certain embodiments, lasofoxifene is administered once every 6 days. In certain embodiments, lasofoxifene is administered once per week. In certain embodiments, lasofoxifene is administered once per 2 weeks. In certain embodiments, lasofoxifene is administered once per 3 weeks. In certain embodiments, lasofoxifene is administered once per month.

[0083] In some embodiments, lasofoxifene is administered to the patient by vaginal ring administration. In some of these embodiments, lasofoxifene is administered once every two weeks. In some of these embodiments, lasofoxifene is administered once every three weeks. In some of these embodiments, lasofoxifene is administered once every month. In some of these embodiments, lasofoxifene is administered once every two months. In some of these embodiments, lasofoxifene is administered once every three months. In some of these embodiments, lasofoxifene is administered once every four months.

[0084] In some embodiments, lasofoxifene is administered as described above in the ER + It is administered to breast cancer patients until the patient's cancer progresses under treatment, goes into complete remission, or side effects become intolerable.

[0085] Combination therapy In various embodiments, lasofoxifene, its pharma- ceutically acceptable salt, prodrug, or functional derivative thereof is administered alone or in combination with other treatments.In certain embodiments, lasofoxifene is administered in combination with at least one other treatment.In some embodiments, lasofoxifene and other treatments are administered together (simultaneously).In some other embodiments, lasofoxifene and other treatments are administered at different times (sequentially).

[0086] In certain embodiments, the additional therapy that the patient is treated with is endocrine therapy. In various embodiments, the patient is treated with at least one additional line of endocrine therapy. In some embodiments, the patient is treated with one additional line of endocrine therapy. In some other embodiments, the patient is treated with multiple additional lines of endocrine therapy. In certain embodiments, the cancer of the patient relapses or progresses after previous treatment.

[0087] In some embodiments, the patient is treated with an additional endocrine therapy at the original dose. In some other embodiments, the patient is treated with an additional endocrine therapy at a higher dose than the original dose. In certain embodiments, the patient is treated with an additional endocrine therapy at a lower dose than the original dose.

[0088] In certain embodiments, the additional endocrine therapy is treatment with a selective ER regulator (SERM) other than lasofoxifene.In some of these embodiments, the selective ER regulator is selected from tamoxifen, raloxifene, bazedoxifene, toremifene, and ospermifene, broparestrol, ormeloxifene, OP-1074, and GDC-0945.In certain embodiments, the selective ER regulator is tamoxifen.

[0089] In certain embodiments, the additional endocrine therapy is treatment with selective ER degrader (SERD).In some of these embodiments, the selective ER degrader binds to estrogen receptor and causes the receptor to be proteasomal degraded.In some embodiments, the selective ER degrader is selected from fulvestrant, RAD1901 (elacestrant), ARN-810 (GDC-0810), giredestrant (GDC-9545), amcenestrant (SAR439859), rintodestrant (G1T48), LSZ102, LY3484356, zN-c5, D-0502, SHR9549, camizestrant (AZD9833) and AZD9496. In certain embodiments, the endocrine therapy is fulvestrant.

[0090] In certain embodiments, the additional endocrine therapy is treatment with an aromatase inhibitor (AI). In some of these embodiments, the aromatase inhibitor is exemestane (Aromasin). (登録商標) ), Letrozole (Femara (登録商標) ), and anastrozole (Arimidex (登録商標) ) is selected.

[0091] In some embodiments, the endocrine therapy is ovarian suppression. In various embodiments, the ovarian suppression is achieved by oophorectomy or treatment with a GnRH antagonist. In some embodiments, the ovarian suppression is achieved by treatment with goserelin (Zoladex®) or leuprolide (Leuprolide®).

[0092] In various embodiments, the additional treatment is the administration of an effective amount of a cell cycle inhibitor to the patient.In certain embodiments, the additional treatment is the administration of an effective amount of a cyclin-dependent kinase 4 / 6 (CDK4 / 6) inhibitor.In some embodiments, the additional treatment is a CDK4 / 6 inhibitor selected from the group of palbociclib, abemaciclib, and ribociclib.

[0093] In various embodiments, the additional treatment is the administration of an effective amount of a cell cycle inhibitor to the patient. In certain embodiments, the additional treatment is the administration of an effective amount of an AKT kinase inhibitor. In some embodiments, the additional treatment is an AKT inhibitor selected from the group of afuresertib, capivasertib and ipatasertib.

[0094] In some embodiments, the additional treatment is the administration of an inhibitor of a pathway that crosstalks with and activates ER transcriptional activity to the patient.In certain embodiments, the additional treatment is a mammalian target of rapamycin (mTOR) inhibitor.In a specific embodiment, the mTOR inhibitor is everolimus.In some of these embodiments, lasofoxifene in combination with everolimus is administered to postmenopausal women with locally advanced or metastatic cancer that progressed under nonsteroidal AI and / or fulvestrant, either as monotherapy or in combination with a CDK4 / 6 inhibitor.In various embodiments, the additional treatment is a phosphoinositide 3-kinase (PI3K) inhibitor or a heat shock protein 90 (HSP90) inhibitor.

[0095] In various embodiments, the additional treatment is administration to the patient of an effective amount of a growth factor inhibitor. In certain embodiments, the additional treatment is a human epidermal growth factor receptor 2 (HER2) inhibitor. In some embodiments, the HER2 inhibitor is trastuzumab (Herceptin (登録商標) In some other embodiments, the HER2 inhibitor is ado-trastuzumab emtansine (Kadcyla). (登録商標) ).

[0096] In some embodiments, the additional treatment is administration to the patient of an effective amount of a histone deacetylase (HDAC) inhibitor. In various embodiments, the HDAC inhibitor is vorinostat (Zolinza). (登録商標) ), romidepsin (Istodax (登録商標) ), chidamide (Epidaza (登録商標) ), panobinostat (Farydak (登録商標) ), Belinostat (Beleodaq (登録商標) , PXD101), valproic acid (Depakote (登録商標) , Depakene (登録商標) , Stavzor (登録商標)), mocetinostat (MGCD0103), abexinostat (PCI-24781), entinostat (MS-275), pracinostat (SB939), resminostat (4SC-201), givinostat (ITF2357), xynostat (JNJ-26481585), kevetrin, CUDC-101, AR-42, tefinostat (CHR-2835), CHR-3996, 4SC202, CG200745, rocilinostat (ACY-1215), or sulforaphane. In certain embodiments, the HDAC inhibitor is entinostat (MS-275), with the proviso that the patient is not being treated with a HER2 inhibitor. In certain other embodiments, the HDAC inhibitor is vorinostat (Zolinza). (登録商標) In yet certain other embodiments, the HDAC inhibitor is romidepsin (istodax). (登録商標) ).

[0097] In some embodiments, the additional treatment is administration to the patient of an effective amount of a checkpoint inhibitor. In certain embodiments, the checkpoint inhibitor is an antibody. In some of these embodiments, the checkpoint inhibitor is an antibody specific for programmed cell death protein 1 (PD-1), programmed death-ligand 1 (PD-L1), or cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4). In some embodiments, the PD-1 antibody is pembrolizumab (Keytruda). (登録商標) ) or nivolumab (Opdivo (登録商標) In some embodiments, the CTLA-4 antibody is ipilimumab (Yervoy). (登録商標) ).

[0098] In certain embodiments, the additional treatment is administration to the patient of an effective amount of a cancer vaccine.

[0099] In some embodiments, the additional treatment is administration to the patient of an effective amount of denosumab.

[0100] In some embodiments, the additional treatment is administration to the patient of an effective amount of a serotonin-norepinephrine reuptake inhibitor (SNRI), a selective serotonin reuptake inhibitor (SSRI), or gabapentin. In certain embodiments, the SNRI is venlafaxine (Effexor). (登録商標) ).

[0101] In some embodiments, the additional treatments described in the preceding paragraphs can be used in combination. Lasofoxifene, its pharma- ceutically acceptable salts, prodrugs, or functional derivatives thereof can be administered in combination with two treatments, such as endocrine therapy (e.g., aromatase inhibitors (e.g., letrozole) and cell cycle inhibitors (e.g., CDK4 / 6 inhibitors (e.g., palbociclib, abemaciclib, and ribociclib)).

[0102] Clinical Endpoints 5.4.3.1. Primary Clinical Endpoint In various embodiments, the method further comprises: + In some embodiments, the method comprises administering an amount of lasofoxifene, a pharma- ceutically acceptable salt, prodrug, or functional derivative thereof, effective to increase disease-free survival in a cancer patient. + In some embodiments, the method includes administering lasofoxifene in an amount effective to reduce the recurrence of the cancer. + In some embodiments, the method includes administering lasofoxifene in an amount effective to increase the time to recurrence of the cancer.+ In some embodiments, the method further comprises administering lasofoxifene in an amount effective to reduce metastasis of the cancer. + The method includes administering lasofoxifene in an amount effective to increase the duration of progression-free survival in a cancer patient.

[0103] In various embodiments, the method further comprises: + In certain embodiments, the method includes increasing disease-free survival of cancer patients. + In certain embodiments, the method reduces the recurrence of cancer. + In certain embodiments, the method increases the time to recurrence of cancer. + In certain embodiments, the method reduces the metastasis of cancer to tissues other than bone. + In certain embodiments, the method reduces the metastasis of cancer to the brain. + In certain embodiments, the method reduces the metastasis of cancer to the lung. + In certain embodiments, the method reduces the metastasis of cancer to the liver. + In certain embodiments, the method further comprises: + and increasing the duration of progression-free survival in cancer patients. The method may include administering lasofoxifene in combination with one or more additional therapeutic agents (as described herein).

[0104] In various embodiments, the method comprises: + In some embodiments, the method increases disease-free survival in cancer patients. In some embodiments, the method reduces cancer recurrence in patients with AI resistance. In some embodiments, the method increases the time to cancer recurrence in patients with AI resistance. In some embodiments, the method reduces cancer metastasis in patients with AI resistance. In some embodiments, the method increases ER progression in patients with AI resistance.+ Increases the duration of progression-free survival in cancer patients.

[0105] In some embodiments, the method further comprises administering to the subject an ER that has developed AI resistance. + In patients with locally advanced or metastatic cancer, the method increases disease-free survival, reduces recurrence, increases time to recurrence, reduces metastasis, and / or increases duration of progression-free survival. In certain embodiments, the cancer has developed AI resistance by acquiring one or more mutations other than gain-of-function mutations in the LBD of ESR1 discussed herein. In some embodiments, the method reduces selection pressure and reduces ER during treatment. + Prevent the expansion of AI-resistant clones in locally advanced or metastatic cancer.

[0106] Secondary Clinical Endpoints In some embodiments, the methods are effective to prevent fractures and bone loss in women who are being concomitantly treated with one or more drugs that cause or predispose to osteoporosis.

[0107] In some embodiments, the methods are effective to decrease vaginal pH, increase vaginal lubrication, and / or improve vaginal cell maturation index in women who are being concomitantly treated with one or more drugs that cause or predispose to vulvovaginal atrophy (VVA).

[0108] In some embodiments, the methods reduce one or more symptoms of sexual dysfunction in women who are being concomitantly treated with one or more drugs that cause or predispose to sexual dysfunction.

[0109] In some embodiments, the methods treat hot flashes in women who are being concomitantly treated with one or more drugs that cause or predispose to hot flashes.

[0110] In some embodiments, the method increases one or more quality of life measures selected from joint pain, genitourinary symptoms, bone loss, and bone fractures.

[0111] EMBODIMENTS OF THE PRESENT DISCLOSURE

[0112] A1a. Lasofoxifene, or a pharma- ceutically acceptable salt, prodrug or functional derivative thereof, for use in a method of reducing progression of an estrogen receptor positive (ER+) cancer in a patient that has progressed on an aromatase inhibitor, wherein the cancer does not have a gain-of-function missense mutation in the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene, said method comprising administering to the patient an effective amount of lasofoxifene, or a pharma-ceutically acceptable salt, prodrug or functional derivative thereof.

[0113] A1b. ER in patients who have progressed on aromatase inhibitors + 1. Lasofoxifene, or a pharma- ceutically acceptable salt, prodrug or functional derivative thereof, for use in a method for reducing metastasis of a cancer, wherein the cancer does not have a gain-of-function missense mutation in the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene, and optionally the method comprises reducing metastasis of the cancer to bone or brain. + and reducing metastasis of cancer, wherein preferably the method comprises: + Lasofoxifene, or a pharma- ceutically acceptable salt, prodrug or functional derivative thereof, which reduces the metastasis of cancer.

[0114] A1c. A combination comprising lasofoxifene, or a pharma- ceutically acceptable salt, prodrug or functional derivative thereof, and a cyclin-dependent kinase 4 / 6 (CDK4 / 6) inhibitor for separate, simultaneous or sequential use in a method of reducing progression of an estrogen receptor positive (ER+) cancer in patients that have progressed on an aromatase inhibitor, wherein said cancer does not have a gain-of-function missense mutation within the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene, and optionally said combination further comprises an aromatase inhibitor (e.g., letrozole).

[0115] A1d. Lasofoxifene, or a pharma- ceutically acceptable salt, prodrug or functional derivative thereof, for use in the treatment of AI-resistant breast cancer that does not express an ERα activating mutation.

[0116] A1e. ER in patients who have progressed on aromatase inhibitors + A combination comprising lasofoxifene, or a pharma- ceutically acceptable salt, prodrug or functional derivative thereof, and a cyclin-dependent kinase 4 / 6 (CDK4 / 6) inhibitor for separate, simultaneous or sequential use in a method of reducing metastasis of cancer, wherein said cancer does not have a gain-of-function missense mutation in the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene, and optionally said combination further comprises an aromatase inhibitor (e.g., letrozole).

[0117] A2. Said ER + Lasofoxifene, or a pharma- ceutically acceptable salt, prodrug or functional derivative thereof, for use according to any one of embodiments A1a to A1e, wherein the cancer is locally advanced or metastatic breast cancer, optionally wherein said cancer is HER2-.

[0118] A3. Lasofoxifene, or a pharma- ceutically acceptable salt, prodrug or functional derivative thereof, for use according to any of the previous embodiments, wherein said aromatase inhibitor is exemestane, letrozole, or anastrozole.

[0119] A4. The method comprises: (i) determining that the cancer does not have a gain-of-function missense mutation in the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene; and (ii) administering to said patient an effective amount of lasofoxifene, or a pharma- ceutically acceptable salt, prodrug, or functional derivative thereof; Lasofoxifene, or a pharma- ceutically acceptable salt, prodrug or functional derivative thereof, for use according to any of the preceding embodiments.

[0120] A5. Lasofoxifene for use according to any of the previous embodiments, wherein the lasofoxifene is administered as lasofoxifene tartrate.

[0121] A6. Lasofoxifene, or a pharma- ceutically acceptable salt, prodrug or functional derivative thereof, for use according to any of the preceding embodiments, wherein the lasofoxifene is administered orally, intravenously, transdermally, vaginally topically, or by vaginal ring administration.

[0122] A7. Lasofoxifene, or a pharma- ceutically acceptable salt, prodrug or functional derivative thereof, for use according to any of the previous embodiments, wherein the lasofoxifene is administered by oral administration.

[0123] A8. Lasofoxifene, or a pharma- ceutically acceptable salt, prodrug or functional derivative thereof, for use according to embodiment A7, wherein the lasofoxifene is administered orally in a dose of 5 mg / day to about 10 mg / day.

[0124] A9. Lasofoxifene, or a pharma- ceutical acceptable salt, prodrug or functional derivative thereof, for use according to any of the previous embodiments, wherein said cancer has a mutation in a gene listed in Table 1.

[0125] A10. Lasofoxifene, or a pharma- ceutically acceptable salt, prodrug or functional derivative thereof, for use according to any of the previous embodiments, wherein the method further comprises treating the patient with at least one additional endocrine therapy.

[0126] A11. The method further comprises administering to the patient an effective amount of a cyclin-dependent kinase 4 / 6 (CDK4 / 6) inhibitor, optionally wherein the CDK4 / 6 inhibitor is administered orally, for example at a dose of 70 mg / kg, Lasofoxifene for use according to any of the preceding embodiments, or a pharma- ceutical acceptable salt, prodrug or functional derivative thereof.

[0127] A12. Lasofoxifene, or a pharma- ceutical acceptable salt, prodrug or functional derivative thereof, and a cyclin-dependent kinase 4 / 6 (CDK4 / 6) inhibitor for simultaneous, separate or sequential use in a method of reducing the progression of estrogen receptor positive (ER+) cancer in patients who have progressed on an aromatase inhibitor, wherein the cancer does not have a gain-of-function missense mutation within the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene.

[0128] A13. Embodiment A11 or A12, wherein the CDK4 / 6 inhibitor is palbociclib, abemaciclib, or ribociclib, optionally wherein the CDK4 / 6 inhibitor is palbociclib, preferably wherein the CDK4 / 6 inhibitor is abemaciclib.

[0129] A14. Lasofoxifene, or a pharma- ceutically acceptable salt, prodrug or functional derivative thereof, for use according to any one of embodiments A1 to A10, wherein the method further comprises administering to the patient an effective amount of an AKT inhibitor.

[0130] A15. Lasofoxifene, or a pharma- ceutical acceptable salt, prodrug or functional derivative thereof, and an AKT inhibitor for simultaneous, separate or sequential use in a method of reducing the progression of estrogen receptor positive (ER+) cancer in patients who have progressed on an aromatase inhibitor, wherein the cancer does not have a gain-of-function missense mutation within the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene.

[0131] A16. Embodiment A14 or A15, wherein the AKT inhibitor is afuresertib.

[0132] A17. Lasofoxifene, or a pharma- ceutically acceptable salt, prodrug or functional derivative thereof, for use according to any one of embodiments A1 to A10, further comprising administering to said patient an effective amount of an mTor inhibitor.

[0133] A18. Lasofoxifene, or a pharmaceutically acceptable salt, prodrug or functional derivative thereof, and an mTor inhibitor for simultaneous, separate or sequential use in a method of reducing the progression of estrogen receptor positive (ER+) cancer in patients that have progressed on an aromatase inhibitor, wherein the cancer does not have a gain-of-function missense mutation within the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene. EXAMPLES

[0134] 5.5.Example Below are examples of specific embodiments for carrying out the present invention. The examples are provided for illustrative purposes only and are not intended to limit the scope of the present invention in any way. Efforts have been made to ensure accuracy with respect to the numbers used (e.g., amounts, temperatures, etc.), but some experimental error and deviation should, of course, be allowed for.

[0135] The practice of the present invention will employ, unless otherwise indicated, conventional methods of molecular biology, cell biology, biochemistry, genetics, cancer biology, and pharmacology, within the skill of the art, which are fully explained in the literature.

[0136] 5.5.1. Example 1: Generation of a Letrozole-Inducible AI-Resistant Breast Tumor Model (MCF-7 Cells) That Does Not Express ERα-Activating Mutations Estrogen receptor positive (ERα + ) Postmenopausal patients with primary invasive breast cancer are typically treated with aromatase inhibitors (AIs) as first-line adjuvant therapy. Patients who become resistant to AIs are treated with fulvestrant and / or CDK4 / 6 inhibitors (e.g., palbociclib) as second-line therapy. Lasofoxifene, a selective estrogen receptor modulator (SERM), was developed for the treatment of vaginal atrophy and osteoporosis. Our previous studies (conducted in the MCF-7 xenograft metastatic breast cancer mouse model with activating ERα mutations) showed that lasofoxifene (both alone and in combination with palbociclib) was more effective than fulvestrant in inhibiting tumor growth and metastasis to the liver, lung, bone and brain in the context of gain-of-function activating mutations in the ERα receptor (encoded by the ESR1 gene).

[0137] In the current study, we compared the efficacy of lasofoxifene (both alone and in combination with palbociclib) to fulvestrant (both alone and in combination with palbociclib) in a breast tumor model using letrozole-inducible AI-resistant cells (LTLT cells) that do not express ERα, which has an activating mutation in the ligand-binding domain.

[0138] Luciferase-GFP tagged LTLT cells were injected into the mammary duct of NSG mice (MIND model), and tumor progression was monitored by liver luminescence imaging of primary tumors, and ex vivo imaging and histochemical analysis of metastatic sites at study endpoints. The area of ​​primary tumors was also measured at study endpoints. Lasofoxifene (alone and in combination with palbociclib) was significantly more effective than fulvestrant (alone and in combination with palbociclib) in inhibiting primary tumor growth. In addition, all treatments except fulvestrant alone inhibited bone metastasis relative to vehicle. These data show that lasofoxifene is more effective than fulvestrant in this tumor model, clearly indicating that lasofoxifene is an effective treatment for AI-resistant breast cancer that does not express ERα activating mutations.

[0139] Cell culture, lentivirus generation and infection, generation of stable cell lines MCF7 LTLT cells (also known as LTLT-Ca cells (Sabnis, G. et al., Cancer Res. 69, 1416-1428 (2009))) express hormone receptor positive (ERα) harboring WT and mutant ERα. + , P.R. + , G.R. +) are derivatives of the human breast cancer cell line MCF7. MCF7 LTLT cells have acquired resistance to aromatase inhibitors. They were originally obtained in the Brodie laboratory by long-term treatment of MCF7aro cells with the aromatase inhibitor letrozole (Sabnis et al., 2009). MCF-7aro cells are stably transfected with the aromatase gene (Sun, XZ et al., J. Steroid Biochem. Mol. Biol. 63, 29-36 (1997)). MCF7 LTLT cells were kindly provided by Ganesh Raj, UT Southwestern. MCF7aro cells were kindly provided by Shiuan Chen, City of Hope.

[0140] To allow in vivo measurement of tumor cell proliferation, we transfected MCF7 LTLT cells with L2G lentiviral vector (pFU-Luc2-eGFP) containing luciferase and GFP under the control of the ubiquitin promoter (Liu, H. et al., Proc. Natl Acad. Sci. USA 107, 18115-18120 (2010)) in suspension at MOI=5 and plated. Cells were grown in RPMI containing 10% FBS and 1 μM letrozole. For cell studies, MCF7 LTLT and MCF7aro cells were transfected with lentiviral nuclear-GFP stain (Nuclight GFP / puro, Cat. No. 4475 Essen Bioscience) according to the manufacturer's recommendations.

[0141] Genotypic evaluation To confirm that aromatase-resistant MCF7 LTLT cells lack ESR1 ligand-binding domain gain-of-function mutations and to investigate non-ESR1 mutations that may confer an endocrine therapy-resistant phenotype to MCF7 LTLT cells, we performed whole-genome exon sequencing and compared the sequence data to two previously reported MCF7 reference sequences (ref. 1 and ref. 2) (Figure 1).

[0142] The MCF7 LTLT cells (LT-LT cells in FIG. 1) lacked ESR1 mutations and were determined to have 18,687 novel variants, including 1508 exonic nonsynonymous variants. Notable genes with variants (63 genes, 85 variants) are listed in Table 1. [Table 1-1] [Table 1-2]

[0143] Phenotypic characterization of MCF7LTLT and MCF7aro via Western blot To characterize the MCF7aro and MCF7 LTLT cell lines, we performed Western blots and probed for ERα, progesterone receptor (PR), androgen receptor (AR) and glucocorticoid receptor (GR).

[0144] Figures 9A-9D show the relative protein levels of ERα and GR protein in MCF7aro and MCF7 LTLT cells compared to ERα in normal MCF7 and T47D cells. Actin expression was used as an internal control for each cell line. As noted, MCF7 LTLT cells express less ERα protein than normal MCF7 cells, and also less than T47D cells (Figure 9A), which is also shown by the ratio of ER to actin expression (Figure 9B). GR protein levels are low in MCF7 LTLT and MCF7aro cells, but similar to T47D cells (Figures 9C-9D). In both assays, actin expression is consistent across cell lines (Figures 9A and 9C).

[0145] Figures 10A-10B show that AR levels are lower in MCF7aro and MCF7 LTLT compared to MCF7 and T47D. Figures 10C and 10D show the presence of HER2, which has previously been reported to be upregulated in MCF7 LTLT cell lines. PR was not detected in any of MCF7, MCF7aro, or MCF7 LTLT cells (Figure 10E).

[0146] 5.5.2. Example 2: Efficacy of Lasofoxifene in AI-Resistant Breast Cancers Lacking Gain-of-Function Mutations in the ESR1 Gene method For letrozole resistance testing, cells were plated at 2500-3000 cells / well in 96-well plates in either RPMI or CS RPMI (SRPMI) and treated with various concentrations of letrozole ranging from 0.1 nM to 10 μM. For experiments performed in SRPMI, cells were cultured in CS serum for 48 h before treatment. Treatment with estradiol and SERM (lasofoxifene) was performed in SRPMI. 96-well plates were scanned every 6 h for up to 1 week in an IncuCyte S3 (Essen Bioscience). Analysis was performed by counting GFP-tagged nuclei via the IncuCyte software.

[0147] Animal testing and injections Mouse studies were performed in compliance with approved Institutional Animal Care and Use Committee protocols. NSG (NOD.Cg-Prkdcscid Il2rgtm1Wjl / SzJ) mice were purchased from The Jackson Laboratories. Prior to injection, mice were anesthetized by inhalation with 2–3% isoflurane in oxygen. Injections of a single cell suspension of 250,000 MCF7 cells into the mammary ducts of inguinal glands 4 and 9 were performed as described (Behbod, F. et al., Breast Cancer Res. 11, R66 (2009); Sflomos, G. et al., Cancer Cell 29, 407-422 (2016); Laine, M. et al., Breast Cancer Res. 23, 54 (2021)). In situ tumor growth was tracked via imaging with a Xenogen IVIS 200 instrument at the Integrated Small Animal Imaging Research Resource at the University of Chicago. For IVIS imaging, mice were injected with 100 μl of 0.1 M luciferin solution (Perkin Elmer XenoLight #122799) in PBS.

[0148] After cell injection, mice were divided into two equal groups; one group received 10 μg / day of letrozole in 15% PEG400 in PBS via subcutaneous injection ("LTLT-Let"); the other group did not receive letrozole ("LTLT"). Two to three weeks after cell injection, mice in each group were randomized and treated with lasofoxifene (10 mg / kg in 100 μl of PBS containing 15% PEG400), palbociclib (70 mg / kg in 50 mM sodium lactate buffer, pH 4, Med Chem Express #HY-50567), or vehicle, 5 days / week. Lasofoxifene and vehicle were administered subcutaneously. Palbociclib was administered 5 times / week via oral gavage. Fulvestrant (Med Chem Express #HY-13636) ("ICI") (5 mg / mouse) was administered via subcutaneous injection in 100 μl mineral oil once a week. Mice were also treated with lasofoxifene + palbociclib, fulvestrant + palbociclib, lasofoxifene + letrozole, and combinations of palbociclib or fulvestrant + palbociclib, or letrozole. [Table 2-1] [Table 2-2]

[0149] After 90-93 days of treatment, mice were sacrificed and mammary tumors were excised and weighed. Following in vivo injection of luciferin 8 min prior to sacrifice, liver, bone, brain and lungs were removed and imaged ex vivo on an IVIS 200 to measure luciferase activity.

[0150] IHC and H&E analysis Harvested tissues were fixed in formalin for IHC and H&E staining. Histology was performed at the Human Tissue Resource Center (HRTC) at the University of Chicago. Primary glands excised from mice were sectioned and stained with antibodies against estrogen receptor alpha (ThermoScientific, RM-9101-S0, clone SP1), progesterone receptor (ThermoScientific, RM-9102-S0, clone SP2), glucocorticoid receptor (Cell Signaling, catalog no. 3660), androgen receptor (Abcam, ab133273, clone EPR1535), Ki67 (ThermoScientific, catalog no. RM-9106-s, clone:SP6), and a human-specific mouse monoclonal antibody against mitochondria (Abcam, ab92824, clone 112-1).

[0151] H&E and IHC slides were scanned with a Nikon eclipse Ti2 microscope equipped with a 10x objective for high resolution images. Ki67 scores were determined using standardized manual counting.

[0152] Western blot analysis Cells were lysed in M-PER lysis buffer (Thermo fisher, catalog number 78501) in the presence of protease inhibitor cocktail 3 (Calbiochem, catalog number 535140). Samples were loaded onto the WES Protein Simple platform. Antibodies used were: estrogen receptor (Santa Cruz, F10 catalog number sc8002), glucocorticoid receptor (Cell signaling, catalog number 12041s), Her2 (Cell Signaling catalog number 2242s), androgen receptor (sigma catalog number sp242), and progesterone receptor (KD68), rat monoclonal antibodies generated in-house (Greene, GL et al., Mol. Endocrinol 2, 714-726 (1988)). Graphical and statistical analysis Graphs and box plots were generated using Graphpad Prism 7 software. p values ​​were determined using an unpaired two-tailed T-test.

[0153] result : Lasofoxifene alone and in combination with palbociclib inhibits MCF7 LTLT primary tumor growth GFP-luciferase labeled MCF7 LTLT cells were injected into the mammary ducts of NSG mice to establish tumors, which represent an AI-resistant non-ESR1 mutant breast cancer model. Treatment with lasofoxifene, palbociclib, and a combination of lasofoxifene and palbociclib was performed in Lett. - To account for potential loss of letrozole resistance ("reversion") in the cohort, + ) or absence (Let -). Mice were imaged biweekly with a Xenogen IVIS scanner to estimate tumor growth. At the end of the study, mammary glands were removed and weighed. In this model, tumors were not palpable; however, the total photon flux of vehicle (solid circle) and fulvestrant (inverted triangle, also referred to as "ICI") treatments was higher than all other treatments (Figures 2 and 3; Let - Only cohorts are shown).

[0154] Photon flux readings for the different treatment groups showed similar patterns in the presence or absence of letrozole, with readings for single treatments of palbociclib or lasofoxifene being 2-3-fold lower than vehicle, and readings for the combination of palbociclib and lasofoxifene being 3-4-fold lower than vehicle (Figures 2 and 3; Letrozole). - (Only cohorts are shown). Photon flux for each treatment at day 104 shows that lasofoxifene, palbociclib, and lasofoxifene + palbociclib are significantly lower than vehicle and fulvestrant (ICI) treatments, regardless of the presence of letrozole. Surprisingly, fulvestrant appeared to increase tumor photon flux in the presence of letrozole, rather than inhibiting it as would be expected (data not shown). This result is an anomaly that is currently unexplained.

[0155] Similar results were observed for mammary gland weights at the end of the study (Figure 4; - (Only the first cohort is shown). However, the differences between gland weights are not as dramatic as for radiance (data not shown), probably because these weights contain some normal mammary tissue that dilutes the tumor weight estimates, whereas radiance measurements reflect only luciferase-expressing tumor cells. In any case, it was found that fulvestrant did not increase mammary gland weight in either group, and in fact, the Let - Inhibits mammary gland weight in the cohort, but Let +The trends between weight and radiance are similar, except for the absence of inhibition in the cohort (data not shown).

[0156] Figure 5 shows Let - Tumor area is shown as a percentage (%) of total tissue in the mammary gland based on H&E staining of representative sections in the cohort. H&E slides were scanned with a Nikon microscope and analyzed with NSI element software. H&E staining was performed using the Let - The results show that the % tumor area in the cohort is significantly lower for lasofoxifene alone compared to vehicle, and that lasofoxifene + palbociclib is significantly lower than vehicle. Palbociclib + fulvestrant (ICI) also reduced the Let - It is significantly lower than the vehicle in this cohort. Lasofoxifene + palbociclib appears to be lower than fulvestrant (ICI) + palbociclib, but this difference does not reach statistical significance. + In cohorts (data not shown), lasofoxifene plus palbociclib was significantly lower than palbociclib plus fulvestrant. Other treatments (e.g., palbociclib or fulvestrant alone) did not reach statistical significance versus vehicle or each other.

[0157] Given these results, we conclude that lasofoxifene (alone and in combination with the CDK4 / 6 inhibitor palbociclib) inhibits primary tumor growth, particularly in the Let -It can be concluded that the combination of lasofoxifene and palbociclib significantly inhibits ER+ breast cancer in this cohort. Overall, the combination of lasofoxifene and palbociclib is clearly superior to all other treatments, especially to the conventional treatment regimen of fulvestrant (alone or in combination with palbociclib). The data show that lasofoxifene or the combination of lasofoxifene and palbociclib is effective in inhibiting primary tumor growth in cancer cells that have developed resistance to letrozole (an aromatase inhibitor (AI) commonly prescribed to treat ER+ breast cancer) through a mechanism other than the acquisition of a gain-of-function mutation in the ligand-binding domain of the ERα receptor (encoded by the ESR1 gene).

[0158] Tumor growth index in the MCF7 LTLT model is significantly increased with letrozole + Low only in the group Immunohistochemistry with anti-Ki67 antibody was performed on fixed mammary glands to determine the proliferation index of MCF7 LTLT primary tumors.

[0159] Letrozole itself significantly reduces the Ki67 percentage from 56.7±9 to 39.5±7.7 compared to vehicle (FIG. 6A). +cohort (Figure 6C), where lasofoxifene alone and lasofoxifene + palbociclib reduce Ki67 percentage by 6.5% and 12.4%, respectively (Figure 6C and Table 3). Table 3 shows the mean % Ki67 measured manually and ± standard deviation for each treatment group. Inspection of the data shows that the effect of lasofoxifene alone is not significant against letrozole control, whereas lasofoxifene + palbociclib significantly reduces Ki67 against palbociclib alone. Interestingly, palbociclib alone or fulvestrant (ICI) alone does not reduce Ki67 % levels in this model. However, fulvestrant plus palbociclib significantly reduced the Ki67 percentage to 18.8±12.3 compared to letrozole control (39.5±7.7) and for palbociclib (45.3±19.0) (Table 3). These results suggest that the proliferation index alone may not be the best measure of lasofoxifene activity in the MCF7 LTLT model. [Table 3]

[0160] Lasofoxifene and lasofoxifene plus palbociclib appear to reduce bone metastases At the time of sacrifice, the liver, lungs, bones and brain were excised and imaged ex vivo with IVIS. - Box plots of the mean radiance for the liver (FIG. 7A), lung (FIG. 7B), brain (FIG. 7C) and bone (FIG. 8A) in the treatment groups are shown. + Data for groups were evaluated but are not shown. The mean radiance for all organs was low, indicating that minimal metastasis was observed. No statistically significant patterns were observed for the liver, lung, and brain, but the lasofoxifene + palbociclib signal was significantly higher than that of the Let - and Let + Visibly lower in the brain than any other treatment versus vehicle for both cohorts.

[0161] Possible metastases to bone were detected (FIG. 8B). However, only three readings in the vehicle group, two in the fulvestrant (ICI) group, and one in the fulvestrant (ICI) + palbociclib group show signals above the threshold. In both cohorts, especially Let - In our cohort, there appeared to be inhibition of radiance for lasofoxifene plus palbociclib versus vehicle, but this did not reach statistical significance.

[0162] In conclusion, taken together, these data show that for this model of AI-resistant breast cancer, where resistance is due to mechanisms other than the acquisition of ESR ligand-binding domain gain-of-function mutations, lasofoxifene (alone or in combination with palbociclib) inhibits primary tumor growth. Furthermore, lasofoxifene (alone or in combination with palbociclib) appears to inhibit metastasis to bone. In general, lasofoxifene in combination with palbociclib is more effective than the combination of fulvestrant and palbociclib in inhibiting primary tumors and metastases of these cells. The data have important clinical implications and clearly indicate the possibility of using lasofoxifene as an effective treatment for women with advanced or metastatic ER+ breast cancer that has become resistant to aromatase inhibitors and lacks ESR1 gain-of-function mutations.

[0163] 6. Equivalents and Incorporation by Reference While the present invention has been shown and described in detail with reference to a primary embodiment and various alternative embodiments, it will be understood by those skilled in the relevant art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.

[0164] All references, issued patents, and patent applications cited within the body of this specification are hereby incorporated by reference in their entirety for all purposes.

Claims

1. Estrogen receptor-positive and human epidermal growth factor receptor 2-negative (ER) breast cancer patients with progression under aromatase inhibitor therapy ＋ 1. A composition for use in a method for reducing the progression of breast cancer, the composition comprising lasofoxifene or a pharmaceutically acceptable salt thereof, wherein the cancer does not have a gain-of-function missense mutation in the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene.

2. The ER ＋ The composition of claim 1, wherein the / HER2- cancer is locally advanced or metastatic breast cancer.

3. 2. The composition of claim 1, wherein the aromatase inhibitor is exemestane, letrozole, or anastrozole.

4. The composition described in claim 1, wherein the method further includes an earlier step of determining that the cancer does not have a gain-of-function missense mutation within the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene.

5. 10. The composition of claim 1, wherein lasofoxifene is administered as lasofoxifene tartrate.

6. The composition of claim 5, wherein lasofoxifene tartrate is administered orally.

7. 7. The composition of claim 6, wherein lasofoxifene tartrate is administered orally in a dose of 5 mg lasofoxifene / day to about 10 mg lasofoxifene / day.

8. The composition described in claim 7, characterized in that lasofoxifene tartrate is administered orally at a dose of 5 mg lasofoxifene / day.

9. 10. The composition of claim 1, wherein the composition is administered to the patient in combination with an effective amount of a cyclin-dependent kinase 4 / 6 (CDK4 / 6) inhibitor.

10. 10. The composition of claim 9, wherein the CDK4 / 6 inhibitor is palbociclib, abemaciclib, or ribociclib.

11. The composition described in claim 10, wherein the CDK4 / 6 inhibitor is palbociclib.

12. The composition described in claim 10, wherein the CDK4 / 6 inhibitor is abemaciclib.

13. The composition described in claim 10, wherein the CDK4 / 6 inhibitor is ribociclib.

14. 10. The composition of claim 1, wherein the composition is administered to the patient in combination with an effective amount of an AKT inhibitor or an mTor inhibitor.

15. A composition for use in a method for reducing the progression of estrogen receptor-positive, human epidermal growth factor receptor 2-negative (ER + / HER2 - ) breast cancer in patients whose breast cancer has progressed under an aromatase inhibitor, the composition comprising lasofoxifene or a pharmaceutically acceptable salt thereof, wherein the cancer does not have a gain-of-function missense mutation in the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene, and the composition is administered to the patient in combination with a cyclin-dependent kinase 4 / 6 (CDK4 / 6) inhibitor.

16. The composition described in claim 15, wherein the CDK4 / 6 inhibitor is palbociclib, abemaciclib, or ribociclib.

17. The composition described in claim 16, wherein the CDK4 / 6 inhibitor is palbociclib.

18. The composition described in claim 16, wherein the CDK4 / 6 inhibitor is abemaciclib.

19. The composition described in claim 16, wherein the CDK4 / 6 inhibitor is ribociclib.

20. The composition described in claim 15, wherein the method further comprises an earlier step of determining that the cancer does not have a gain-of-function missense mutation within the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene.

21. The composition of claim 15, wherein lasofoxifene is administered as lasofoxifene tartrate.

22. The composition of claim 21, wherein lasofoxifene tartrate is administered orally at a dose of 5 mg lasofoxifene / day.

23. The composition described in claim 15, characterized in that it is administered to the patient in combination with an effective amount of an AKT inhibitor or mTOR inhibitor.

24. The composition described in claim 15, wherein the combination of lasofoxifene and a CDK4 / 6 inhibitor inhibits metastasis of the breast cancer to bone.

25. A composition for use in a method for reducing the progression of estrogen receptor-positive, human epidermal growth factor receptor 2-negative (ER + / HER2 - ) breast cancer in patients whose breast cancer has progressed under aromatase inhibitors, the composition comprising lasofoxifene or a pharmaceutically acceptable salt thereof, wherein the cancer does not have a gain-of-function missense mutation in the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene, and the cancer has at least one variant in at least one gene set forth in Table 1.

26. The composition of claim 25, wherein lasofoxifene is administered orally as lasofoxifene tartrate.

27. ​​The composition described in claim 26, characterized in that lasofoxifene tartrate is administered orally at a dose of 5 mg lasofoxifene / day.

28. The method comprising, in any order: determining that the cancer does not have a gain-of-function missense mutation within the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene; and determining that the cancer has at least one variant in at least one gene set forth in Table 1; 26. The composition of claim 25, further comprising the steps of:

29. The composition described in claim 25, characterized in that it is administered to the patient in combination with an effective amount of a cyclin-dependent kinase 4 / 6 (CDK4 / 6) inhibitor.

30. The composition described in claim 29, wherein the CDK4 / 6 inhibitor is palbociclib, abemaciclib, or ribociclib.

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