Temsirolimus (TEM) maintenance therapy after response of castration-resistant prostate cancer (CRPC) to docetaxel (TAX).

e15177^ Background: There are no standard treatments for men who have demonstrated a good response to TAX without signs of progression. The mTOR pathway is involved in many aspects of CRPC, and mTOR inhibitors have shown significant anti-CRPC activity in preclinical testing. Therefore, we designed a phase II trial to explore whether maintenance therapy with TEM has the potential to prolong response to TAX without compromising quality of life. Methods: For this single-arm, multicenter phase II trial we recruited CRPC pts with documented treatment response by PSA (> 50% decline from baseline) or RECIST (1.0) criteria following ≥ 6 to 10 cycles of TAX (75 mg/m2 q3wks). Subjects received weekly TEM (25 mg iv x 4/cycle). The primary endpoint was time to treatment failure (TTF; RECIST or symptomatic progression). Secondary endpoints included safety (NCI-CTCAE v3.0), quality of life (FACT-P, PPI), changes in PSA, objective tumor response rate, and overall survival. We were also studying surrogate markers of TEM ...