e21062 Background: Platinum-based chemotherapy is the standard therapy for the patients(pts) with EGFR-mutation–positive advanced NSCLC failed to prior EGFR TKI therapies. However, the IMpower150 study subgroup analyses showed Atezolizumab (PD-L1) plus bevacizumab and chemotherapy improved overall survival in EGFR TKI treated NSCLC. This ongoing phase I/II study designed to assess the benefit of the chemo-free combination of TQ-B2450, a humanized PD-L1 mAb, plus anlotinib in EGFR+ advanced NSCLC pts failed to prior EGFR TKI therapies. Methods: Pts with EGFR+ advanced NSCLC who failed to prior EGFR TKI therapies were eligible. Pts with previous received platinum-based chemotherapy were excluded. Anlotinib was given orally at dose of 8mg to 12mg for 2 weeks of a 21-day cycle (days 1-14), with TQ-B2450 given at 1200mg every 3 weeks on day 1. Phase I determined RP2D. In the phase II part, pts were assessed for efficacy and tolerability. The primary endpoint for the phase II part is the progression free survival (PFS). Secondary endpoints were objective response rate (ORR) disease control rate (DCR), overall survival (OS), and safety. Assuming an expected the median PFS of 9 months (5 months in chemotherapy), and a loss to follow-up of 10%, a total of 54 pts were required to have 90% power at a two-tailed alpha of 0.05 at the phase II part. Results: As of 12 Jan 2021, 22 pts were enrolled (9 in phase 1, 14 in phase 2). 18 pts were included in efficacy and safety analysis. The median age was 64.5 years with 61% male. 50% pts harbored EGFR exon19 deletion, 44% pts had exon21 L858R mutation. While 39% pts had T790M mutation who progressed after osimertinib treatment. The dose escalation cohort included 9 pts, no dose limiting toxicity occurred. 13 pts in the phase II part were administered with dose of 12 mg for anolitinib and 1200mg for TQ-B2450. Of the evaluable pts(n = 18), ORR was 11.1%, DCR was 77.8%, median PFS was 8.0 months (95% CI 4.9 to 11.1). Most frequent TRAE included hypertension (27.8%), hand and foot skin reaction (22.2%) and proteinuria (16.7%). Grade 3 TRAE occurred in 16.7% pts(3/18 pts), all were hypertension, and no Grade 4/5 TRAE were observed. Dose delay due to TRAE occurred in 22.2% patients while no one discontinued treatment due to TRAE. Conclusions: The chemo-free combination of TQ-B2450, a PD-L1 mAb, plus anlotinib has shown a promising anti-tumor efficacy with a more favorable safety profile for pts with EGFR+ advanced NSCLC who failed to prior EGFR TKI therapies. Pts will be continuously monitored for safety and efficacy readouts (PFS, DOR and OS). Clinical trial information: ChiCTR1900026273. Clinical trial information: ChiCTR1900026273.
P2-293: Final results of a phase 1/2 study of biweekly pemetrexed and gemcitabine in patients with advanced NSCLC
