Clinical observation of Pemetrexed first-line treatment in advanced non-squamous lung cancer or non-small cell lung cancer without driver-mutations: a phase 2, single-arm trial.

Background Non-dominant population, which means patients with advanced non-squamous lung cancer or non-small cell lung cancer (NSCLC) without driver-mutations, who are excluded from clinical studies because of specific baseline conditions refractory to multiple treatments, have poor outcomes. We assessed the activity of pemetrexed first-line treatment for a non-dominant population, explore the safety and efficacy of pemetrexed therapy. Methods We did this two-phased, single-arm trial at two sites at the Fifth Affiliated Hospital of Sun Yat-sen University and Guangxi medical university cancer hospital. Pemetrexed 500 mg/m2, static drops on day 1; 21 days for a cycle, each treatment for at least two cycles and up to six cycles. Efficacy was assessed every two cycles. Results We counted the July 21, 2018 to 2020 on May 31, first diagnosed with IIIb-IV period (American Joint Committee on Cancer eighth edition) no drive genes, non-squamous cell carcinomas, 30 patients with non-small cell lung cancer, the follow-up to July 31, 2020, median follow-up time was 12 months. Most were elderly patients with poor general conditions (96.7% of patients had ECOG scores of 2-3) (median age 66 years). Median duration of maintenance treatment was 6 months. Median progression-free survival was 6.5 months. Median overall survival was 12 months. Patients with performance status =0-2 had a significantly higher median overall survival time (16 months) compared with patients with performance status =3 who had a median overall survival time of 7 months (P=0.001). Most treatment-related adverse events were grade 1 or grade 2. Conclusions This study is the first to investigate the survival benefit and toxicity tolerance of pemetrexed treatment in non-dominant population in the real world, providing a new therapeutic possibility for those who failed to be enrolled in clinical studies.