A phase 2, open-label, single-arm study evaluating the combination of pembrolizumab (pembro), lenvatinib, and chemotherapy in patients (pts) with metastatic non-small cell lung cancer (NSCLC) harbouring a targetable mutation who experienced disease p

198 Background: Pts with metastatic NSCLC harbouring a targetable mutation who progressed on standard TKIs often receive chemotherapy as the next line of treatment. We report efficacy and safety of a novel combination of pembro, lenvatinib and chemotherapy for these pts. Methods: This was a phase 2, open-label, single-centre, single-arm study enrolling pts with metastatic NSCLC with sensitizing EGFR, ALK or ROS1 mutation who progressed on standard TKIs. Eligible pts had measurable disease, no untreated brain metastasis and ECOG PS ≤1. Pts received pembro 200 mg, pemetrexed 500 mg/m 2 and carboplatin AUC 5 every 3 weeks for 4 cycles plus lenvatinib 8 mg QD. The maintenance regimen without carboplatin was continued as tolerated for up to 2 years. The primary endpoint was objective response rate (ORR) by independent radiology review (IRR) as per RECIST 1.1. The secondary endpoints were PFS, overall survival (OS) and safety. Results: At the data cutoff date (2 nd February 2024), 24 pts were screened and 19 were enrolled: median age 64 years (range 29–77); 10 (53%) female. Four pts were excluded at screening due to untreated brain metastasis. All enrolled pts were evaluated for safety while 15 pts were evaluable for response. All pts had adenocarcinoma with targetable mutation: EGFR mutation in 18 (95%) pts and ALK fusion in 1 (5%) pt. The median follow-up time was 11.3 months. Treatment was ongoing in 8 pts on the date of analysis, while 6 pts permanently discontinued due to disease progression and 1 pt permanently discontinued due to a treatment-related adverse event (TRAE). The ORR was 40% (6/15, 95% CI 19.8%–64.3%). All responses were partial responses. The median PFS was 11.9 months (range 3.5–20.3). The OS was not reached. TRAEs of any grade (Gr) occurred in 74% (14/19) of the pts. Most of the TRAEs were Gr 1–2, which occurred in 63% (12/19) of the pts. The most common TRAEs were hypothyroidism (31.6%), nausea (26.3%), neutropenia (26.3%), thrombocytopenia (26.3%), anorexia (21.1%), hypertension (15.8%), anaemia (10.5%), pruritus (10.5%) and rash (10.5%). G1 diarrhoea was reported in 1 pt (5.3%) and G1 adrenal insufficiency in 1 pt (5.3%). Gr 3 TRAEs were neutropenia in 2 pts, anaemia in 1 pt and thrombocytopenia in 1 pt. The only Gr 4 TRAE was thrombocytopenia. No treatment related death was observed. Conclusions: The combination of pembro, lenvatinib and chemotherapy demonstrated a favourable ORR and safety in treating metastatic NSCLC pts with a targetable mutation who progressed on standard TKIs. Clinical trial information: NCT04989322 .