Asian Subgroup Analysis of Patients in the Phase 2 DeLLphi-301 Study of Tarlatamab for Previously Treated Small Cell Lung Cancer

Abstract

IntroductionTarlatamab is a bispecific T-cell engager (BiTE (R)) immunotherapy that binds delta-like ligand 3 on the surface of small cell lung cancer (SCLC) cells and CD3 on T cells, facilitating T cell-mediated cancer cell lysis. In the primary analysis of the phase 2 DeLLphi-301 study (NCT05060016), tarlatamab showed a favourable benefit-to-risk profile with durable objective responses and promising survival outcomes in patients with previously treated SCLC. Here, phase 2 data for the Asia region subgroup are presented.MethodsPatients with previously treated, advanced SCLC received 10 mg tarlatamab every 2 weeks. The primary endpoint was objective response rate (ORR) by blinded independent central review (RECIST version 1.1). Key secondary endpoints included duration of response (DOR), progression-free survival (PFS), overall survival (OS) and safety. The present analysis includes patients enrolled at sites in Asia.ResultsA total of 43 patients were enrolled at sites in Asia. ORR was 46.3% (95% confidence interval [CI], 30.7-62.6) and median DOR was 7.2 months (95% CI 3.9 to not estimable). The median follow-up was 16.6 months for PFS and 21.2 months for OS. Median PFS was 5.4 months (95% CI 3.0-8.1) and median OS was 19.0 months (95% CI 11.4 to not estimable). The most common treatment-emergent adverse event (AE) was cytokine release syndrome (48.8%), and all such events were grade 1 or 2. There were no discontinuations due to treatment-related AEs.ConclusionsTarlatamab demonstrated durable responses and promising survival outcomes with a manageable safety profile in this post hoc analysis of patients from Asia with previously treated SCLC.Trial RegistrationClinicalTrials.gov, NCT05060016.