Medical Oncology Department, Santa Chiara Hospital, Trento, Italy.
Although there is no standard treatment after docetaxel failure in patients with castration-resistant prostate cancer (CRPC), second-line chemotherapy is increasingly required. Its mechanism of action and toxicity profile make pemetrexed suitable for testing in this setting.
Patients with docetaxel-resistant CRPC received pemetrexed 500 mg/m(2) every 3 weeks for 6 courses. The usual premedication with vitamin supplementation and dexamethasone prophylaxis was regularly administered. The primary objective was to quantify the biochemical response rate.
The biochemical response rate was 10.5% (95% CI 1.3-33.1), with 2 patients showing a reduction in prostate specific antigen (PSA) of ≥50%. The null hypothesis that the PSA response rate would be less than 20% was therefore accepted, and patient accrual was stopped after the evaluation of the 19th patient. The 1-year overall survival rate was 61.5%, with a median survival of 14 months. A considerable proportion of the patients (36%) were withdrawn from the study because of hematologic and nonhematologic toxicity.
Our experience with pemetrexed in CRPC patients appears discouraging in terms of activity and toxicity. No further studies of this drug should be performed in CRPC patients.
Written by:
Caffo O, Fratino L, Barbieri R, Perin A, Martini T, Sava T, Segati R, Vaccher E, Bernardo Bassan F, Veccia A, Pappagallo G, Galligioni E. Are you the author?
Reference: Urol Oncol. 2011 Jul 29. Epub ahead of print.
doi: 10.1016/j.urolonc.2010.11.012
PubMed Abstract
PMID: 21803618
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