HE-3235

Prostate cancer is a common cancer in men; for metastatic disease, it has a 5-year survival rate of 30%. No FDA-approved therapy for castrate-resistant prostate cancer (CRPC) known to improve survival was available until 2004, when based on a significant survival benefit over mitoxantrone, docetaxel in combination with prednisone was approved. In combination with prednisone, cabazitaxel, which was approved in the United States in 2010, is indicated for patients with metastatic CRPC previously treated with a docetaxel-containing regimen. This case report describes the treatment of a man 58 years of age who was diagnosed with advanced prostate cancer in 2006. He was initially managed with radical prostatectomy followed by androgen deprivation therapy, but a rising prostate-specific antigen (PSA) level led to enrollment in a clinical trial of HE3235 for 6 months. Subsequently, with progression of disease, he was treated with docetaxel for 4 months and then palliative radiation therapy. Cabazitaxel was initiated in October 2010; his condition stabilized within weeks, and he experienced a progressive decline in his PSA level from a peak of 5,424 ng/ml. Continued treatment with cabazitaxel resulted in his being weaned off pain medications and resuming his normal activities. After 16 cycles of cabazitaxel, his PSA declined to 994 ng/ml as of January 2012. He tolerated the cabazitaxel well and occasionally received myeloid growth factors for treatment of neutropenia; otherwise, he experienced only mild diarrhea. This response to cabazitaxel is notable, particularly in light of prior failure of multiple therapies.

N-methyl-N-nitrosourea (MNU) induces estrogen-dependent mammary tumors in female Lewis rats. We explored the antineoplastic activity of a synthetic androstane derivative, 17α-ethynyl-5α-androstane-3α, 17β-diol (HE3235), as a single agent or in combination with docetaxel compared to tamoxifen, anastrazole, and docetaxel monotherapies against MNU-induced mammary tumors in female Lewis rats. Treatment with HE3235 alone rapidly reduced tumor burden, similar in effect to tamoxifen and anastrozole. The combination of HE3235 with docetaxel was more effective than any single agent, although without apparent toxicity. Only HE3235 or HE3235 plus docetaxel continued to suppress tumor growth after cessation of treatment. HE3235 treatment increased immunohistochemical markers of apoptosis and expression of proapoptotic genes and estrogen receptor beta and decreased expression of antiapoptotic genes, androgen receptor, and estrogen receptor alpha. These data warrant clinical investigation of HE3235 for breast cancer treatment.