ASCO: Chemotherapy Doesn't Help in Malignant Mesolthelioma

June 7, 2007

CHICAGO, June 7 -- Adding chemotherapy to active symptom control did not extend survival or significantly improve quality of life in patients with malignant pleural mesolthelioma.

CHICAGO, June 7 -- Adding chemotherapy to active symptom control did not extend survival or significantly improve quality of life in patients with malignant pleural mesolthelioma.

So said Jeremy P. Steele, M.D., of St. Bartholomew's Hospital, London, in reporting the first results of the phase III Medical Research Council/British Thoracic Society (MS) 01 trial at the American Society of Clinical Oncology meeting here.

Active symptom control included treatment with steroids and palliative radiotherapy, as well as close monitoring by oncologists. In the trial, patients were randomized to the control arm (active symptom control) or to one of two chemotherapy regimens on top of active symptom control, Dr. Steele said.

Both chemotherapy regimens-four cycles of mitomycin (6 g/m2), vinblastine (6 g/m2), and cisplatin (50 mg/m2) administered once every three weeks or 12 weekly injections of vinorelbine (30 mg/m2)-had demonstrated efficacy as palliative treatment in phase II trials.

The phase III researchers found no significant difference in overall survival when active symptom control was compared with either of the two chemotherapy arms, nor did they find a significant difference in overall survival when the control arm was compared with the combined chemotherapy arms, Dr. Steele said.

However, he noted, median survival was longer in the vinorelbine arm (9.4 months) than in the vinblastine-cisplatin arm (7.8 months) or the control arm (7.6 months). But here, too, he said, the difference was not statistically significant.

Importantly the trial "demonstrated that chemotherapy was, indeed, very feasible contrary to the common view in England that chemotherapy is hopelessly toxic in these patients," Dr. Steele said.

Based on the observed increase in median survival with vinorelbine, although clearly not significant at P=0.11, he said, "one could make a case for further investigation of vinorelbine."

The trial failed to meet the target accrual of 840 patients over four years to detect a three-month improvement in median survival, so the two chemotherapy arms were combined for purposes of analysis and the target accrual was dropped to 420 patients.

Dr. Steele reported results from 409 patients-136 controls, 136 in the vinorelbine arm, and 137 in the vinblastine-cisplatin arm.

All patients accrued to the trial demonstrated good symptom palliation, and there was no significant difference in symptom improvement across arms. All regimens were well tolerated.

Dr. Vogelzang disclosed financial support from Genentech and Lilly Oncology. Dr. Steele disclosed no conflicts. The trial was funded by the British Medical Research Council and the British Thoracic Society.