Low-dose docetaxel, estramustine and thalidomide followed by maintenance thalidomide in androgen-independent prostate cancer (AIPC): Final results of a phase II community based study in elderly men

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Background: The TET regimen was developed to test the potential synergy and tolerability of low dose, metronomic chemotherapy plus an anti-angiogenesis agent in the treatment of AIPC in elderly men. Preliminary results were presented in 2004 (ASCO Proceedings #4681); we now present the final results 5 years from protocol initiation. Methods: Eligible patients had progressive AIPC, an adequate PS (0–2) and were chemotherapy naïve. All patients received the TET regimen: Docetaxel (Taxotere [T]) 25 mg/m2 weekly for three weeks per month, Estramustine 140 mg po tid x 3 days per week (with T) and Thalidomide (Thal) 100–200 mg as tolerated. After six monthly cycles of TET, patients with responding or stable disease received maintenance Thal until progression. Coumadin 2 mg daily was given for thromboprophylaxis. A total of 19 patients out of an intended 25 were accrued from 6/01 to 9/05. Results: The median age was 79 (59–86); 70% of patients were ≥ 75 years of age. The median PSA was 83 (20–2266), median Gleason score 7, bone metastases were present in 14/19 patients and measurable disease in 12/19 patients. 17 patients completed at least one cycle of TET and were eligible for analysis. The PSA declined >50% in 10/17 (59%); there was 1 PR and 7 SD by RECIST criteria. Of six patients that received maintenance Thal, only one had PSA stabilization for more than three months. The median survival was 17 months. The major grade ¾ toxicities included non-life threatening DVT (3 patients), asthenia (6 patients), edema and dyspnea (one patient each). Thal 200 mg was especially poorly tolerated, requiring dose reductions in over half of the patients. Conclusions: In this trial of elderly men with AIPC, low-dose TET did not seem to improve upon the results previously reported for docetaxel or docetaxel/estramustine. The observed toxicities make it doubtful that a higher dose TET regimen could be tolerated by this population. Thalidomide maintenance was ineffective in maintaining responses.

No significant financial relationships to disclose.