High-dose cisplatin in hypertonic saline: reduced toxicity of a modified dose schedule and correlation with plasma pharmacokinetics. A Northern California Oncology Group Pilot Study in non-small-cell lung cancer.

Although increased efficacy has been described with a five-day schedule of high-dose cisplatin (CDDP) in hypertonic saline, severe myelosuppression and cumulative neurotoxicity have limited the usefulness of this therapy. In order to evaluate a possible dose-response relationship in non-small-cell lung cancer (NSCLC), 17 patients with metastatic disease were treated with a modified dose schedule delivering the same total dose (200 mg/m2) in a divided day 1 and 8 schedule. During a pilot study, a total of 47 cycles of therapy were administered, with a median of three cycles per patient and a median total cumulative dose of 600 mg/m2. Nine of 17 patients received at least 600 mg/m2. While nephrotoxicity was similar to previous reports of the five-day schedule, the incidence and severity of myelosuppression and peripheral neuropathy were markedly reduced. Using this modified schedule, severe myelosuppression did not occur. Clinically severe peripheral neuropathy developed in only one patient (6%). The overall response rate was 47% (eight of 17 patients). Plasma platinum pharmacokinetics during five cycles of the modified day 1 and 8 schedule were compared with pharmacokinetics of the five-day schedule. Accumulation of plasma ultrafiltrate platinum occurred in the five-day schedule, but not in the day 1 and 8 schedule. This difference in pharmacokinetics is one possible explanation for the reduced toxicity of this modified schedule. Although the degree of activity seen in this pilot study is encouraging, the efficacy of high-dose CDDP in NSCLC remains to be defined. In view of reduced myelosuppression and neurotoxicity, further trials with this modified schedule are indicated.