Pemetrexed Maintenance Improves Progression-Free Survival in Patients With NSCLC

Luis Paz-Ares, MD, PhD

Continuation maintenance with pemetrexed (Alimta) improves progression-free survival (PFS) in patients with advanced nonsquamous non—small cell lung cancer (NSCLC) who received pemetrexed as part of their initial chemotherapy regimen, according to data presented Sunday at the ASCO conference in Chicago.

“Maintenance treatment is given to patients in the hope that we can keep the disease under control for a longer time, with the hope to increase PFS and survival,” said lead author Luis Paz-Ares, MD, PhD, chair of oncology at Seville University Hospital in Seville, Spain.

He noted that pemetrexed has been shown to be an effective maintenance treatment in patients with NSCLC who had not received the drug as part of their initial treatment regimen. Paz-Ares and his colleagues sought to determine if pemetrexed would provide the same, or better, benefit to patients who had used the compound in their primary treatment.

The PARAMOUNT study cohort consisted of 939 patients who were given a standard 4 courses of first-line induction treatment with (500 mg/m²) and cisplatin (75 mg/m²) on day 1 of a 21-day cycle. Paz-Ares noted that cancer did not progress in 539 patients from the initial group. The researchers then randomized these patients into 2 arms: 359 patients who received maintenance pemetrexed (500 mg/m²on day 1 of a 21-day cycle) and best supportive care, and 180 patients who received a placebo and best supportive care.

Mark G. Kris, MD

The investigators reported that pemetrexed maintenance resulted in a 38% reduction in the risk of disease progression. They found a median PFS of 4.1 months for those in the pemetrexed group compared with 2.8 months in the placebo group (P = .00006).

The disease control rate was 71.8% in the pemetrexed arm compared with 59.6% on placebo. Discontinuations due to adverse events were 5.3% on the pemetrexed arm and 3.3% on the placebo arm. According to Paz-Ares, the toxicity profile of maintenance therapy was very favorable (lower than 5%) and in accordance with previous single-agent pemetrexed.

“PARAMOUNT met its primary endpoint by showing significantly improved PFS in patients treated with pemetrexed continuation maintenance therapy as compared to placebo,” said Paz-Ares. “The highly significant PFS results demonstrate that pemetrexed continuation maintenance therapy is an effective treatment for patients with advanced nonsquamous NSCLC following pemetrexed plus cisplatin induction therapy.”

“This trial gives the medical oncologists who fight lung cancer a very important piece of information,” noted Mark G. Kris, MD, chief of the Thoracic Oncology Service and The William and Joy Ruane Chair in Thoracic Oncology at Memorial Sloan-Kettering Cancer Center in New York City, moderator of the press conference at which the PARAMOUNT results were unveiled.

Paz-Ares LG, De Marinis F, Dediu M, et al. PARAMOUNT: phase III study of maintenance pemetrexed (pem) plus best supportive care (BSC) versus placebo plus BSC immediately following induction treatment with pem plus cisplatin for advanced nonsquamous non—small cell lung cancer (NSCLC).J Clin Oncol. 29:2011(suppl; abstract CRA7510).