Long-term and low-grade safety results of a phase III study (PARAMOUNT): maintenance pemetrexed plus best supportive care versus placebo plus best supportive care immediately after induction treatment with pemetrexed plus cisplatin for advanced nonsquamous non-small-cell lung cancer.

Introduction: In the PARAMOUNT ("A Phase 3, Double-Blind, Placebo-Controlled Study of Maintenance Pemetrexed plus Best Supportive Care vs. Best Supportive Care Immediately Following Induction Treatment with Pemetrexed Plus Cisplatin for Advanced Non-Squamous Non-Small-Cell Lung Cancer") trial, patients with advanced nonsquamous non-small-cell lung cancer (NS-NSCLC) benefited from pemetrexed maintenance therapy after induction therapy with pemetrexed and cisplatin by extending survival, delaying disease progression, and maintaining quality of life (QoL). However, low-grade 1 or 2 toxicities during long-term maintenance treatment may become burdensome and impact QoL.

Materials And Methods: Patients in this double-blind study (n = 539), who had completed 4 induction cycles (pemetrexed with cisplatin) without progressive disease (PD) and had an ECOG performance status of 0/1, were randomized 2:1 to pemetrexed maintenance (500 mg/m(2), day 1) plus best supportive care (BSC) or placebo plus BSC until PD. Adverse events (by maximum Common Terminology Criteria for Adverse Events [CTCAE] grade) and QoL (EuroQol 5-dimensional [EQ-5D] scale) were assessed.

Results: A median of 4 maintenance cycles was administered (range, pemetrexed 1-44; mean ± SD 7.9 ± 8.3; placebo 1-38; mean ± SD 5.0 ± 5.2), with 28% of pemetrexed and 12% of placebo patients receiving ≥ 10 maintenance cycles. The pemetrexed dose intensity was 94%. More patients receiving pemetrexed (12%) than placebo discontinued because of possible drug-related CTCAEs (4%; P = .005). Overall, pemetrexed was associated with significantly more (P < .05) low-grade events (grade 1/2 nausea, grade 2 anemia, edema, and neutropenia) than placebo. Overall, the incidence of low-grade fatigue, anemia, and neutropenia decreased with long-term pemetrexed exposure; however, renal events increased across treatment arms. EQ-5D analyses demonstrated no treatment-by-time interaction or overall treatment differences between the 2 arms.

Conclusion: PARAMOUNT demonstrated a low incidence of low-grade toxicities with long-term pemetrexed exposure without compromising QoL in patients with NS-NSCLC.