Open-label study of pemetrexed alone for chemonaive patients and pre-treated patients with malignant pleural mesothelioma: Outcomes of the International Expanded Access Program (EAP)

Abstract

7709 Background: In a previous phase II study of chemonaive malignant pleural mesothelioma (MPM) patients (pts), single-agent pemetrexed (P) resulted in a 14.1% response rate (RR) and median survival of 10.7 mos (95% CI 7.7–14.5) (Scagliotti 2003). Likewise, the P arm in a phase III study of pre-treated MPM pts yielded an 18.7% RR (40.7% with stable disease, SD) and median survival of 8.4 mos (95% CI 6.2–10.5) (Jassem 2006). The EAP provided 3311 MPM pts with access to P alone, P plus cisplatin, or P plus carboplatin in 13 countries. In this abstract we report on the safety and efficacy data of those MPM pts treated with P alone. Methods: Eligible pts had histologic or cytologic diagnosis of MPM and were either chemonaïve or previously treated with =1 line(s) of chemotherapy. Pts pre-treated with P were allowed if they had experienced clinical benefit from the prior P. Treatment consisted of P (500 mg/m2) once (day 1) every 21 days with standard pre-medication of vitamin B12, folic acid, and dexamethasone. Investigator-determined response (RR) and survival data (with censoring) were recorded at the end of study participation. Myelosuppression data (CTC) were also collected. Results: 812 MPM pts (319 chemonaïve; 493 pre-treated) received =1 dose of P and were evaluated for safety, and 643 pts (247 chemonaïve; 396 pre-treated) were evaluated for efficacy (RR and survival). In chemonaïve pts with MPM, the median age was 69 yrs (range: 39–87 yrs), 78.1% were male, and 71.6% had a KPS ≥80 (of the 93% who had PS evaluated). In pre-treated pts with MPM, the median age was 63 yrs (range: 31–85 yrs), 75.9% were male, and 74.5% had a KPS ≥80 (of the 95% who had PS evaluated). Both groups received a median of 4 cycles (chemonaive group range 1–18; pretreated group range 1–23). See the table for efficacy and safety data. Conclusions: Results of the EAP confirm earlier phase II and phase III studies. No significant financial relationships to disclose. [Table: see text]