Androgen Receptor Modulation Optimized for Response-Splice Variant: A Phase 3, Randomized Trial of Galeterone Versus Enzalutamide in Androgen Receptor Splice Variant-7-expressing Metastatic Castration-resistant Prostate Cancer.

Background: Detection of androgen receptor (AR) splice variant-7 (AR-V7) messenger RNA (mRNA) in circulating tumor cells (CTCs) is associated with a suboptimal response to abiraterone and enzalutamide in metastatic castration-resistant prostate cancer (mCRPC). Galeterone inhibits CYP17 and AR, and induces AR protein degradation. We hypothesized that galeterone would be clinically superior to enzalutamide in AR-V7-positive (AR-V7+) mCRPC.

Androgen Receptor Modulation Optimized for Response (ARMOR) Phase I and II Studies: Galeterone for the Treatment of Castration-Resistant Prostate Cancer.

Purpose: Galeterone is a selective, multitargeted agent that inhibits CYP17, antagonizes the androgen receptor (AR), and reduces AR expression in prostate cancer cells by causing an increase in AR protein degradation. These open-label phase I and II studies [Androgen Receptor Modulation Optimized for Response-1 (ARMOR1) and ARMOR2 part 1] evaluated the efficacy and safety of galeterone in patients with treatment-naive nonmetastatic or metastatic castration-resistant prostate cancer (CRPC) and established a dose for further study.

Experimental Design: In ARMOR1, 49 patients received increasing doses (650-2,600 mg) of galeterone in capsule formulation; 28 patients in ARMOR2 part 1 received increasing doses (1,700-3,400 mg) of galeterone in tablet formulation for 12 weeks.

A phase I open label study of the farnesyltransferase inhibitor CP-609,754 in patients with advanced malignant tumors.

Purpose: The purpose of this phase I clinical trial was to determine the maximum-tolerated dose and toxicity of CP-609,754 in patients with solid tumors refractory to standard therapies, to determine the cellular effects of CP-609,754 on its molecular target (farnesyltransferase), and to determine the recommended phase II dose (RP2D) of this agent.

Experimental Design: Consenting patients with adequate bone marrow, liver, and renal function were enrolled with an accelerated dose strategy with single-patient parallel cohorts in whom the drug was given orally either once or twice daily. Once a dose-limiting toxicity was encountered or two patients developed Common Toxicity Criteria > or = grade 2 toxicities, a modified Fibonacci sequence was initiated.