Gemcitabine and cisplatin in unresectable malignant mesothelioma of the pleura: a phase II study of the Southwest Oncology Group (SWOG 9810).

Purpose: The purpose of this open-label phase II SWOG study was to evaluate the activity of gemcitabine (Gemzar; Eli Lilly, Indiana, USA) and cisplatin combination therapy, in patients with unresectable malignant mesothelioma of the pleura.

Patients And Methods: Fifty eligible chemotherapy naïve patients with histologically proven malignant mesothelioma of the pleura, and a SWOG performance status 0-2 were enrolled between February 1999 and August 2000. Treatment consisted of gemcitabine 1000mg/m(2) and cisplatin 30mg/m(2) on days 1, 8 and 15 of a 28-day cycle, until progression of disease or two cycles beyond complete response.

Results: Using SWOG response criteria, one patient had a confirmed complete response and five patients had a confirmed partial response, for a total response rate of 12% (95% CI 5-24%). All the responses were seen in patients with epithelioid or unspecified histology. Stable disease was seen in 25 patients (50%). The median overall survival was 10 months (95% CI 7-15 months), with a median progression-free survival of 6 months. Sixteen patients experienced Grade 4 toxicity. Twelve of these Grade 4 toxicities were hematologic. There were no treatment-related deaths.

Conclusions: Cisplatin-gemcitabine combination chemotherapy has modest activity with an acceptable toxicity profile, as first line treatment for patients with malignant mesothelioma.