Safety of tarlatamab with 6-8-h outpatient versus 48-h inpatient monitoring during cycle 1: DeLLphi-300 phase 1 substudy
A.C. Chiang, M.E. Olmedo García, Jennifer W. Carlisle, Afshin Dowlati, Noemı́ Reguart, Enriqueta Felip, Philipp J. Jost, Neeltje Steeghs, Rafał Stec, Shirish M. Gadgeel, Herbert H. Loong, Weiguo Jiang, A. Hamidi, Andrew Parkes, L. Paz-Ares
Abstract
BACKGROUND: Tarlatamab, a bispecific T-cell engager immunotherapy targeting delta-like ligand 3, has demonstrated promising survival outcomes in small-cell lung cancer (SCLC). Given the risk of cytokine release syndrome (CRS), initial clinical trials incorporated 48-72-h inpatient monitoring in cycle 1. METHODS: Patients with previously treated SCLC were enrolled into DeLLphi-300 part F, which evaluated the safety of tarlatamab 10 mg every 2 weeks (Q2W) with 6-8-h outpatient monitoring following cycle 1 doses. The primary endpoint, safety, was compared with patients from DeLLphi-300 part A receiving tarlatamab 10 mg Q2W with 48-h inpatient monitoring for cycle 1 doses. RESULTS: In cycle 1, the rates of treatment-related adverse events and hospitalizations, including emergency room visits, were similar between outpatient (n = 30) and inpatient (n = 58) groups (93% versus 100% and 27% versus 34%, respectively). The incidence of all grade and serious CRS during cycle 1 was similar between outpatient and inpatient groups (any grade: 60% versus 62%; serious: 17% versus 22%). The median time to CRS resolution was 3 days for both groups. CONCLUSIONS: Safety outcomes, including hospitalization rates, were similar in this first-in-human study following tarlatamab 10 mg Q2W administration with 6-8-h outpatient versus 48-h inpatient monitoring in cycle 1.