Phase I clinical trial and pharmacokinetics of carboplatin (NSC 241240) by single monthly 30-minute infusion.

Carboplatin (diammine [1,1-cyclobutanedicarboxylate(2-)-O,o']platinum) is a second generation platinum coordination complex. It has a spectrum of activity that is similar to that of cisplatin and is less nephrotoxic and emetogenic in experimental animals. Fifty-two 30-minute infusions of carboplatin were given to 20 evaluable patients with a variety of solid tumors. Maximum tolerated dose was 440 mg/m2. Thrombocytopenia (less than 100,000/mm3) occurred in six of seven patients; two patients experienced a leukocyte count less than 2000/mm3. Platelet and leukocyte count nadirs occurred on day 21. No nephrotoxicity was seen. Blood urea nitrogen, serum creatine levels, and creatinine clearances remained normal, and no consistent elevation of urinary beta 2-microglobulin, leucine aminopeptidase, or N-acetyl-beta-glucosaminidase occurred. Nausea and vomiting were mild to moderate. A single patient developed mild peripheral neuropathy. No auditory toxicity was noted. The recommended dose for Phase II studies is 400 mg/m2 every 28 days for good risk patients; heavily pretreated patients should receive 320 mg/m2.