Several studies have shown the efficacy, tolerability, and ease of administration
of pemetrexed-an antifolate antineoplastic agent-in patients with advanced non-small-cell
lung cancer. We assessed pemetrexed as maintenance therapy in patients with this disease.
This randomised double-blind study was undertaken in 83 centres in 20 countries. 663
patients with stage IIIB or IV disease who had not progressed on four cycles of platinum-based
chemotherapy were randomly assigned (2:1 ratio) to receive pemetrexed (500 mg/m(2),
day 1) plus best supportive care (n=441) or placebo plus best supportive care (n=222)
in 21-day cycles until disease progression. Treatment was randomised with the Simon
and Pocock minimisation method. Patients and investigators were masked to treatment.
All patients received vitamin B(12), folic acid, and dexamethasone. The primary endpoint
of progression-free survival and the secondary endpoint of overall survival were analysed
by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00102804.
All randomly assigned participants were analysed. Pemetrexed significantly improved
progression-free survival (4.3 months [95% CI 4.1-4.7] vs 2.6 months [1.7-2.8]; hazard
ratio [HR] 0.50, 95% CI 0.42-0.61, p<0.0001) and overall survival (13.4 months [11.9-15.9]
vs 10.6 months [8.7-12.0]; HR 0.79, 0.65-0.95, p=0.012) compared with placebo. Treatment
discontinuations due to drug-related toxic effects were higher in the pemetrexed group
than in the placebo group (21 [5%] vs three [1%]). Drug-related grade three or higher
toxic effects were higher with pemetrexed than with placebo (70 [16%] vs nine [4%];
p<0.0001), specifically fatigue (22 [5%] vs one [1%], p=0.001) and neutropenia (13
[3%] vs 0, p=0.006). No pemetrexed-related deaths occurred. Relatively fewer patients
in the pemetrexed group than in the placebo group received systemic post-discontinuation
therapy (227 [51%] vs 149 [67%]; p=0.0001).
Maintenance therapy with pemetrexed is well tolerated and offers improved progression-free
and overall survival compared with placebo in patients with advanced non-small-cell
lung cancer.
Eli Lilly.