Phase II trial of fenretinide in advanced renal carcinoma

Fenretinide, a synthetic form of retinoid, induced apoptosis even in chemotherapy resistant cell lines. A phase II study was hence conducted to evaluate toxicity and efficacy of fenretinide in metastatic renal cancer.

Eligibility included unresectable or metastatic renal cell carcinoma (RCC), adequate organ function and Zubrod performance status < or =2. Prior immunotherapy and a maximum of one prior chemotherapy regimen were allowed. Fenretinide was administered at a dose of 900 mg/m(2) twice daily orally for 7 days in a 21-day cycle. Toxicity was assessed at the start of each cycle, and response every 2 cycles.

Nineteen eligible patients enrolled of which fifteen had visceral/bone metastases. Seventeen patients had prior nephrectomy and 11 had prior immunotherapy. 76 cycles of therapy were delivered. Therapy was very well tolerated with few severe toxicities consisting of thrombosis in 1 individual and grade 3 fatigue, nausea and diarrhea in 1 patient. 5 patients had grade 2 nyctalopia and 3 patients had transient grade 2 visual toxicity. No objective responses were noted. Stable disease was seen in seven of nineteen cases (37%, 90% C.I. 0.21-0.59). Median time to progression was 1.5 months and median duration of stable disease was 5.8 months (90% C.I. 3.0-8.4). Median survival was 10 months. Tumor fenretinide levels were obtained in three patients and were in the lower end of the therapeutic range.

Fenretinide was well tolerated but demonstrated minimal activity that was consistent with results of intratumoral drug measurements. Strategies are needed that will increase systemic and tumor levels of fenretinide.