A phase II trial of merbarone (NSC 336628) as salvage therapy for squamous cell carcinoma of the cervix. A Gynecologic Oncology Group Study.

Twenty-seven patients with previously irradiated unresectable recurrent squamous carcinoma of the cervix who had failed one prior cytotoxic regimen received 1,000 mg/m2 per day of merbarone given by continuous i.v. infusion for 5 days every 4 weeks through a central line. One patient was never treated, and four were inevaluable for response, leaving 26 patients evaluable for toxicity and 22 evaluable for response. The major adverse effect was myelosuppression with 6/26 (23%) experiencing Gynecologic Oncology Group (GOG) grade 3 or 4 leukopenia. There were two episodes (3.8%) of GOG grade 3 SGOT elevation. There were two patients (9.0%) who developed mental status changes classified as grade 3 neurotoxicity. This neurotoxicity may have been secondary to iatrogenic hyponatremia caused by the large volumes of 5% glucose infusion required at the original infusate concentration. After the concentration of the merbarone infusate was increased to 4 mg/ml, no further problems with hyponatremic neurotoxicity were encountered. The overall response rate was 2/22 (9.0%) (95% confidence interval 1.1-29.2%). In this pretreated population with recurrent squamous cervical carcinoma, merbarone exhibited only minimal activity.