Phase I/II trial of accutane as a potentiator of carboplatin and paclitaxel in squamous cell carcinomas.

This study investigated the toxicity and efficacy of a 13-cis retinoic acid, carboplatin, and paclitaxel (Taxol) regimen in 18 patients with recurrent or metastatic squamous cell carcinomas (12 head and neck, 4 cervix, 1 esophagus, and 1 anus). Three patients were treated at each dose level with fenretamide (Accutane) 1 mg/kg/d orally for 14 days, carboplatin AUC of 5 mg/ml.min intravenously (IV) and paclitaxel at a dose of 135, 155, 175, 195, 205, or 225 mg/m(2) IV on day 8 every 4 weeks for 6 cycles. Fifteen evaluable patients had a total of 72 treatment cycles. There were 21 grade III or IV toxicities distributed among all the dose levels, including neutropenia, anemia, thrombocytopenia, elevated prothrombin time/partial thromboplastin time, elevated alkaline phosphatase, weight loss, alopecia, and three deaths from aspiration pneumonia and septic shock. The maximum tolerated dosage included 205 mg/m(2) paclitaxel. There was one complete response, three partial responses, and 2 stable diseases. The three partial responses were in the four patients with cervical cancer. Responses did not correlate with expression of retinoic acid receptor subtypes. Toxicity profiles and overall response rates were comparable to prior studies with similar chemotherapy regimens alone. The data support further study in a phase II trial.