Clinical option of pemetrexed-based versus paclitaxel-based first-line chemotherapeutic regimens in combination with bevacizumab for advanced non-squamous non-small-cell lung cancer and optimal maintenance therapy: evidence from a meta-analysis of randomized control trials.

Background: In the era of immunotherapy, it is still unclear which is the best first-line therapy for patients with oncogenic driver negative advanced non-squamous non-small cell lung cancer (NS-NSCLC) who cannot tolerate immunotherapy, or subsequent therapy for patients with oncogenic driver positive NS-NSCLC whose disease progressed on prior targeted therapy. To assess the optimal choice of first-line and maintenance treatment regimens, we performed a meta-analysis of prospective randomized controlled clinical trials (RCTs) of patients with NS-NSCLC on bevacizumab combined with chemotherapy.

Methods: All eligible RCTs comparing pemetrexed-platinum with or without bevacizumab (PP ± B) and paclitaxel-carboplatin with bevacizumab (PC + B) as a first-line therapy, or comparing bevacizumab plus pemetrexed (Pem + B) and bevacizumab alone (B) as a maintenance treatment for advanced NS-NSCLC, were included after systematically searching web databases and meeting abstracts. The main research endpoints were comparisons of overall survival (OS) and progression-free survival (PFS). The other endpoints were objective response rate (ORR), 1-year PFS rate (PFSR1y) and major grade 3/4 treatment-related adverse events.

Results: Data of 3139 patients from six RCTs were incorporated into analyses. Three RCTs were included in an analysis that compared PP ± B and PC + B as a first-line therapy for advanced NS-NSCLC. Patients treated with first-line PP ± B showed similar OS and ORR, but significantly improved PFS (hazard ratio [HR], 0.88) and PFSR1y (risk ratio [RR], 0.83), as compared to patients treated with PC + B (all P < 0.05). PP ± B resulted in higher rates of grade 3/4 anemia and thrombocytopenia, but lower rates of neutropenia, febrile neutropenia, and sensory neuropathy than PC + B (all P < 0.001). The other three RCTs were included in an analysis that compared Pem + B and B as a maintenance treatment. Compared with B, Pem + B maintenance treatment resulted in significant improvements in OS (HR, 0.88), PFS (HR, 0.64), and PFSR1y (RR, 0.70), but higher rates of anemia, thrombocytopenia, and neutropenia (all P < 0.001).

Conclusion: Although the first-line PP + B regimen had longer PFS and PFSR1y than the PC + B regimen, no OS difference was observed. Addition of pemetrexed to bevacizumab as maintenance therapy significantly improved OS compared with bevacizumab maintenance alone, but led to more toxicity.