Sunitinib malate for metastatic castration-resistant prostate cancer following docetaxel-based chemotherapy

Systemic therapy options are limited for metastatic castration-resistant prostate cancer (CRPC) patients who progress following docetaxel (Taxotere). This phase II trial evaluated sunitinib malate in patients with progressing metastatic CRPC following prior docetaxel.

Patients with metastatic CRPC progressing following one to two chemotherapy regimens including docetaxel were included. The primary end point was progression-free survival (PFS) per radiographic and clinical evaluations. Oral sunitinib was administered 50 mg/day 4-weeks on followed by 2-weeks off per cycle up to a maximum of eight cycles or until clinical progression or intolerable toxicity.

Thirty-six patients with a median age of 69.5 years were accrued. The median PFS was 19.4 weeks with a 12-week PFS of 75.8%. Four patients (12.1%) had a > or =50% prostate-specific antigen (PSA) decline and seven (21.2%) had a > or =30% PSA decline. Two of 18 patients (11.1%) with measurable disease demonstrated 30% declines by RECIST and eight (44.4%) displayed some shrinkage. A decline in pain score > or =2 points occurred in 13.6% of 22 assessable patients. Drug discontinuation due to toxic effects occurred in 52.8% of patients.

Sunitinib malate demonstrated promising activity in metastatic CRPC progressing after prior docetaxel.