Phase II study of iproplatin (CHIP) in previously treated small-cell lung cancer

Eighteen patients with previously treated extensive small-cell carcinoma of the lung were entered into a Phase II study employing iproplatin (CHIP), a cis-platin analog. Patients had received a mean of two prior chemotherapeutic regimens. Fifty-five percent had received prior cis-platinum and 33% had received prior radiation therapy. CHIP (225 mg/m2) was administered by intermittent intravenous infusion over 30 min for 5 days of a 28-day cycle without prehydration. Sixteen patients with Zubrod performance scores of less than or equal to 3 received 27 courses of therapy (mean 1.7, range 1-6). One partial response of 167 days duration was observed, with complete regression of involved lymph nodes and stabilization of nonevaluable disease in the chest. Six patients had stable disease following one cycle of CHIP, but all progressed following a second cycle of drug. The main toxicity was myelosuppression with prominent thrombocytopenia. Median survival was 75 days from initiation of therapy. In this group of heavily pretreated patients with advanced disease, iproplatin has only minimal activity as a single agent and does not show non-cross-resistance with cis-platinum.