Survival update on a subset of peritoneal mesothelioma (PM) patients in an expanded access program (EAP) of pemetrexed (P) alone or combined with cisplatin in the treatment of malignant mesothelioma (MM)

Abstract

7174 Background: A phase III trial of mesothelioma pts showed improved efficacy for P with cisplatin versus cisplatin alone, leading to a demand for patient access to P prior to regulatory approval. In order to gather additional efficacy and safety data, an Eli Lilly and Company EAP was opened to allow access to P for all eligible pts with MM. Methods: Patients were treated once every 21 days with P 500mg/m2 alone or with cisplatin 75mg/m2, for a maximum of 6 cycles. Chemotherapy naïve pts received the combination of cisplatin plus P, while pre-treated pts received P alone. All pts were supplemented with folic acid, vitamin B12, and received steroid prophylaxis. Results: There were 1056 pts with MM that received at least one dose of study drug at 462 sites in the United States. Of the 98 pts with PM there were 38 chemotherapy naïve pts (M 74%, F 26%; Median age: 65), 57 previously treated pts (M 56%, F 42%; Median age: 58), and 3 missing. The most commonly reported serious adverse events in the EAP regardless of causality were: dehydration (7.2%), nausea (5.2%), vomiting (4.9%), dyspnea (3.8%), and pulmonary embolism (2.4%). In seventy-three pts evaluated for response there were: 4 CRs (5.5%), 15 PRs (20.5%), 33 SDs (45.2%), and 21 PDs (28.8%) for an objective response rate of 26.0% (95% CI 16.5–37.6%). Median survival has not been reached for chemotherapy naïve pts (95% CI=7.6, –; 81.6% censorship) and median survival is 13.1 months for previously treated pts (95% CI=7.8, 13.1; 77.2% censorship). Conclusions: The toxicity observed for all pts enrolled in the EAP group is acceptable. The disease control rate (CRs+PRs+SDs) of 71.2% in the subset of pts with peritoneal mesothelioma indicates activity in this patient population. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Eli Lilly Eli Lilly Eli Lilly Eli Lilly Eli Lilly