MEDICATION AGAINST ESTROGEN-RECEPTOR b (ER.beta) POSITIVE BREAST TUMOR

Abstract

The present invention relates to the field of medicine, and refers to the steroid compound 4-hydroxyandrost-4-ene-3,17-dione (4-OHA) or ester thereof, as a prodrug for use in the treatment of a patient suffering from estrogen-receptor β (ERβ) positive breast tumour. The present invention further relates to a pharmaceutical composition comprising said steroid compound for topical application, and the use of said steroid compound in a pre-surgical topical treatment of ERβ-positive breast cancer tissue.

Claims

1.-19. (canceled)

20. A method for treatment of a patient suffering from estrogen-receptor β (ERβ) positive breast tumor, comprising administering to a patient in need of the treatment a steroid compound 4-hydroxyandrost-4-ene-3,17-dione (4-OHA) of formula I ##STR00006## Formula I, or ester thereof, as a prodrug, wherein said prodrug is applied topically to the patient.

21. The method according to claim 20, wherein said patient suffering from ERβ positive breast tumor is also androgen receptor (AR) positive, or wherein said patient suffering from ERβ positive breast tumor is an AR negative breast tumor and in particular a triple negative breast cancer in terms of estrogen-receptor α (ERα) negative, progesterone-receptor (PR) negative and HER2-receptor negative.

22. The method according to claim 20, wherein the treatment takes place prior to a planned surgical removal of breast tumor tissue, and/or wherein the treatment is for reducing the breast tumor tissue.

23. The method according to claim 20, wherein said prodrug 4-OHA is metabolized to a pharmacologically active substance which has at least a hydroxyl-group in C4-position and C17-position.

24. The method according to claim 20, wherein the prodrug 4-OHA is metabolized to a pharmacologically active substance which has a higher binding affinity towards estrogen-receptor beta (ERβ) as compared with its binding affinity towards estrogen-receptor alpha (ERα), which are either both expressed by the breast tumor tissue, or only ERβ is expressed by the breast tumor tissue, wherein said treatment results in agonistic binding of ERβ, preferably wherein said pharmacologically active substance exhibits a binding affinity towards ERβ that is at least 3 times, preferably at least 4, 5, or 6 times, more preferably at least 9 times and most preferably at least 10 times higher compared to the binding affinity towards ERα.

25. The method according to claim 20, wherein the pharmacologically active substance is 4-hydroxy-5-alpha-androstane-3-beta,17beta-diol (4-OHBA) or 4-hydroxytestosterone (4-OHT).

26. A method for treatment of a patient suffering from estrogen-receptor β (ERβ) positive breast tumor, comprising administering to a patient in need of the treatment 4-Hydroxytestosterone (4-OHT) or 4-Hydroxy-5-alpha-androstane-3-beta,17beta-diol (4-OHBA) or the respective hydroxy-esters of 4-OHT or 4-OHBA, wherein 4-OHT or 4-OHBA or the respective hydroxy-esters of 4-OHT or 4-OHBA is applied topically to the patient.

27. The method according to claim 6, wherein the patient suffers from triple negative breast cancer in terms of estrogen-receptor α (ERα) negative, progesterone-receptor (PR) negative and HER2-receptor negative, comprising administering 4-OHT.

28. A method for treatment of a patient suffering from estrogen-receptor β (ERβ) positive breast tumor, comprising administering to a patient in need of the treatment a pharmaceutical composition suitable for topical application comprising the steroid compound 4-hydroxyandrost-4-ene-3,17-dione (4-OHA) of formula I ##STR00007## Formula I, or ester thereof, as a prodrug and pharmaceutically acceptable carrier(s) and/or excipient(s).

29. The method according to claim 28, wherein the treatment takes place prior to a planned surgical removal of the breast tumor tissue, and/or wherein the pre-surgical treatment comprises the topical application of the pharmaceutical composition in an amount effective for reducing the breast tumor tissue.

30. The method according to claim 28, wherein said patient suffering from ERβ positive breast tumor is also androgen receptor (AR) positive, or wherein said patient suffering from ERβ positive breast tumor is an AR negative breast tumor and in particular a triple negative breast cancer in terms of estrogen-receptor α (ERα) negative, progesterone-receptor (PR) negative and HER2-receptor negative.

31. The method according to claim 28, wherein the treatment is carried out over a period of time that is sufficient for effecting the reduction of the breast tumor tissue to a size that allows for the breast-preserving surgical removal of the breast tumor tissue.

32. The method according to claim 28, wherein the tumor tissue is significantly reduced upon completion of the treatment, preferably the tumor tissue is reduced by at least 14 vol.-%, or at least 20 vol.-%, preferably by at least 30 vol.-%, more preferably by at least 40 vol.-%, even more preferably by at least 50 vol.-%, compared to the size of the breast tumor tissue at the beginning of the treatment, as determined by mammography, X-ray or ultrasound, preferably as determined by mammography.

33. The method according to claim 29, wherein the pre-surgical treatment starts no later than 6 months, or no later than 5, 4, 3, or 2 months, prior to the planned surgery, that is, the breast-preserving surgical removal of the breast tumor tissue.

34. The method according to claim 28, wherein the prodrug 4-OHA or ester thereof is present in the pharmaceutical composition in an amount of from about 0.01 wt.-% to about 4 wt.-%, preferably in an amount of from about 2.0 wt.-% to about 3.0 wt.-%, more preferably in an amount of about 2.5 wt.-%, based on the weight of the pharmaceutical composition.

35. The method according to claim 28, wherein the pharmaceutical composition is applied topically once or twice a day.

36. The method according to claim 28, wherein the pharmaceutical composition comprises, in addition to the prodrug 4-OHA or ester thereof and/or in addition to the compound selected from 4-OHT, 4-OHBA and esters of 4-OHT and 4-OHBA, additionally another active ingredient which binds to ERβ and thereby activates ERβ, particularly when the ERβ positive breast cancer is triple-negative breast cancer (TNBC).

37. The method according to claim 36, wherein the other active ingredient is selected from antiestrogens and anticarcinogen indol compounds, preferably wherein the antiestrogen is fulvestrant or tamoxifen and wherein the anticarcinogen indol compound is indole-3-carbinol.

38. A method for treatment of ERβ-positive breast cancer tissue, comprising a pre-surgical topical administration of 4-OHA or ester thereof as a prodrug.

Description

FIGURES

[0136] FIG. 1 is a diagram showing the specific binding in [%] according to the invention.

[0137] FIG. 2 is a diagram showing two different concentrations of MDA MB-231 cells that are incubated with increasing concentration of 4-OHT (K+).

[0138] FIG. 3 is a diagram showing mean tumor volumes prior and post 2.0% SAVE cream therapy

[0139] The following examples illustrate, but do not limit the invention.

Examples

1. Observation of Shrinking of Breast Tumor Tissue

[0140] 1.1 Patients that were diagnosed (by mammography) with ERβ positive breast cancer tumors with a maximum size of 2 cm were treated with the pharmaceutical composition comprising the prodrug of the present invention: The prodrug was applied topically to the affected breast.

[0141] Already after three weeks of treatment, a reduction in tumor size could be observed.

[0142] 1.2 Application of 4 ml of a crème (2 times/day) comprising 2.5 wt.-% 4-OHA to a breast suffering from an ER positive breast cancer. Already after 3-5 weeks, the size of the tumor was significantly decreased.

2. Comparison of Treatment Success of Anastrozol and Letrozol with the Prodrug of the Present Invention

[0143] Studies were carried out on patients suffering from ERβ positive breast cancer.

[0144] First, the patients were treated with non-steroidal aromatase-inhibitors Anastrozol or Letrozol, the treatment was carried out according to the respective current treatment guidelines. However, the respective treatment was not successful.

[0145] Then, said patients were treated with the pharmaceutical composition comprising the prodrug according to the present invention, that is, the prodrug (4-OHA) was applied topically to the affected breast.

[0146] It was observed that in 50% of the patients treated in this way, a stabilisation of the disease over 6 months could be reached.

3. Inhibition of Proliferation of MDA MB-231 Cells During Incubation with 4-OHT

[0147] MDA-MB-231 cell line is a highly aggressive, invasive, and poorly differentiated epithelial human breast cancer cell line. It lacks estrogen receptor a (ERα) and progesterone receptor (PR) expression, as well as HER2 (human epidermal growth factor 2) amplification. MDA-MB-231 cell line is ERβ positive. It is a model cell line for triple negative breast cancer (TNBC) being ERβ positive.

[0148] Two different concentrations of MDA-MB-231 cells (1.0e3 and 2.5e3) were incubated with increasing concentrations of 4-OHT (K+; 0.5 μM; 1 μM; 5 μm; 10 μM; 20 μM). The cells were incubated for 6 days (d). Then, absorption at 492 nm was measured.

[0149] In the diagram in FIG. 2 it is shown that, starting at an end concentration of at least 5 μM/L 4-OHT, a significant inhibition of cell growth takes place. Inhibition of cell growth at 5 μM/L 4-OHT is about 50% (at a cell concentration of 1.0e3), with an increase in inhibition of cell growth to about 75% to 80% at a 4-OHT concentration of 20 μM/L.

4. Observation of Shrinking of Triple Negative Breast Tumor Tissue (TNBC)

[0150] The tumor of 16 breast cancer patients suffering from ERα positive and ERβ positive breast cancer (“ER+”) and 6 breast cancer patients being ERβ positive and suffering from TNBC (“ER-”: AR negative; HER2neu negative; ERα negative) has been treated with a cream containing 4-OHA as active ingredient (“SAVE Cream”) in a typical non-active cream base.

[0151] The tumor has been treated for about three weeks (average duration of treatment: 21.2 days) with 4-OHA. The administered dose was as follows: 2×2 or 2×4 g 2.0 wt.-% 4-OHT in the cream base (“SAVE cream”) per breast daily.

[0152] The mean tumor volumes were assessed prior and post treatment with the 4-OHT-containing cream. As can be seen, in ER+ patients the shrinkage of the tumor volume (mm.sup.3) was 75%, and the shrinkage of the tumor volume in ER− patients was 14%. This is surprising and remarkable, as in particular TNBC is known as a type of breast cancer that can be very aggressive: Due to the lack of expression of ERα, PR, and HER2/neu, the effect of hitherto known treatments is not satisfying. However, as could be shown, upon treatment with the 4-OHT-containing cream, a shrinkage of the tumor volume of 14% could be reached.