MA11.03 Pembrolizumab Plus Docetaxel Increases Progression-Free Survival Compared with Docetaxel Alone in Previously Treated Advanced Non-Small Cell Lung Cancer Patients

Immunotherapy is now the standard of care for non-small cell lung cancer patients without actionable mutations, due to a clear survival benefit in large phase III trials, further this benefit can be translated into the first-line setting, alone or in combination with chemotherapy. Nonetheless, due to several circumstances many patients do not receive immunotherapy as first-line. The effect of the combination therapy with pembrolizumab plus docetaxel in previously-treated NSCLC patients has not been prospectively assessed. In this phase II clinical trial, we evaluated the effect of a combination therapy with pembrolizumab plus Docetaxel (PD) compared with Docetaxel (D) for the treatment of advanced NSCLC patients who had progressed to previous lines of therapy. Primary endpoint was overall response rate (ORR); secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety profile. Eighty patients met the inclusion criteria and were enrolled in the study, among which 78 were randomized 1:1. Forty patients were allocated to receive PD, while thirty-eight were allocated to receive D. Baseline characteristics, including sex, age, tobacco index, performance status and EGFR mutation were well-balanced between both arms of the trial. We found a statistically significant difference in terms of ORR (42.5% vs. 15.8%; OR: 3.9 [95%CI: 1.34-11.5]; p=0.01), in patients receiving PD compared with D alone. Further, patients receiving PD had a significantly longer PFS compared with those receiving D monotherapy (9.5 months [95%CI: 4.2-NR] vs. 3.9 [95%CI: 3.2-5.7]; HR: 0.24 [95%CI: 0.13-0.46]; p<0.001). In the multivariate analysis the therapeutic intervention was an independently associated factor with better PFS (Figure). In terms of safety, a total of 22.5% vs. 5.3% of patients experienced any-grade pneumonitis in the PD and D arm of the trial respectively (p=0.048), while 27.5% vs. 16% experienced any-grade hypothyroidism (p=0.20). No new safety signals were identified. Patients who receive the combination therapy have a significantly increased ORR and PFS, with a significant decrease in the hazard of progressing. This work was performed through a grant from MSD (Investigator Initiated Study). The sponsor did not have any role in the acquisition or interpretation of the data.