Single-agent therapy with either bevacizumab or pemetrexed is efficacious as maintenance therapy for patients with advanced nonsquamous non–small cell lung cancer (NSCLC), but the combination of the two agents offers no survival benefit and is more toxic, results of the randomized ECOG-ACRIN 5508 study show.
For patients with no disease progression after four cycles of induction chemotherapy who were assigned to one of three maintenance therapy strategies, there were no differences in overall survival between those randomized to monotherapy with pemetrexed or bevacizumab or to a combination of the two agents, although progression-free survival (PFS) was better with the combination, reported, from the Winship Cancer Institute of Emory University, Atlanta, and colleagues.
The incidence of grade 3 or greater adverse events was also significantly higher with the combination, compared with bevacizumab monotherapy.
Even in the age of immune checkpoint inhibitor therapy in the front line, “[i]t is clear that maintenance therapy will remain an integral part of the treatment approach to advanced nonsquamous NSCLC. The results of ECOG-ACRIN 5508 support the use of either pemetrexed or bevacizumab as a single agent in this setting,” the investigators wrote in the.
Although the combination of bevacizumab and pemetrexed was associated with a significant improvement in PFS in a, the three maintenance strategies have never before been directly compared, Dr. Ramalingam and associates noted.
In ECOG-ACRIN 5508, 1,516 patients with advanced nonsquamous NSCLC who had not received prior systemic therapy were given standard induction chemotherapy, consisting of carboplatin to an area under the curve of 6, paclitaxel 200 mg/m2, and bevacizumab 15 mg/kg for up to four cycles.
Patients without progression after four cycles (874) were randomly assigned to maintenance therapy with bevacizumab at 15 mg/kg , pemetrexed 500 mg/m2, or a combination of the two agents.
For the primary endpoint of overall survival, with bevacizumab serving as the control group for comparison, the investigators found that, at a median follow-up of 50.6 months, median survival was 15.9 months with pemetrexed, compared with 14.4 months with bevacizumab, a difference that was not statistically significant. Median survival with the combination was 16.4 months and was also not significantly different from bevacizumab.
Median PFS was 4.2 months and 5.1 months for the pemetrexed and bevacizumab groups, respectively, with no significant difference. In contrast, median was 7.5 months with the combination, which was significantly better than controls, with a hazard ratio of 0.67 (P less than .001).
Patients received a median of six maintenance therapy cycles for each of the single agents, and a median of eight for the combinations. The incidence of grade 3-4 toxicity was 29% with bevacizumab, 37% with pemetrexed, and 51% with the combination. The combination was associated with a significantly greater incidence of toxicities, compared with bevacizumab (P less than .001).
The study was supported by grants from the National Cancer Institute. Dr. Ramalingam reported a consulting/advisory role for bevacizumab maker Genentech/Roche and others. Multiple coauthors reported similar disclosures.
SOURCE: Ramalingam SS et al. J Clin Oncol. 2019 Jul 30. .