Phase I clinical and pharmacologic trial of carboplatin daily for 5 days.

Twenty-two patients with refractory tumors received 64 courses of iv bolus carboplatin every day X 5, every 4-5 weeks. All patients are evaluable for toxicity and 18 are evaluable for response. For solid tumor phase II studies, a dose of 77 mg/m2/day X 5 is recommended for patients who have received prior chemotherapy. Patients with no prior chemotherapy experience should receive 99 mg/m2/day X 5. The major dose-limiting side effect is dose-related thrombocytopenia. Courses of carboplatin on this schedule should be repeated every 5 weeks to avoid cumulative wbc count toxicity, since leukopenia frequently did not occur until Day 28. Other toxic effects observed were nausea and vomiting and lower-extremity myalgias and arthralgias. There was no evidence of hearing loss, mucosal damage, or changes in liver or renal function tests of any patient while in this study. Therapeutic responses were seen in four patients: one partial response in renal cancer of 9+ months' duration; one partial response in head and neck cancer of 7+ months' duration; and objective responses in melanoma and colorectal carcinoma of 6 months' duration.