Presenting Author: Alyssa Cendagorta, PharmD, BCOP, Robert Wood Johnson University Hospital, New Brunswick, NJ
BACKGROUND: Risks of the bispecific T-cell engager tarlatamab include cytokine release syndrome (CRS) and immune effector cell–associated neurotoxicity syndrome (ICANS). As part of the FDA’s accelerated approval, patients are required to be monitored in a healthcare facility after cycle 1 day 1 and day 8 doses.1 A more recent protocol does not require hospitalization for the monitoring of CRS; rather, it recommends 6 to 8 hours of postinfusion monitoring.2 Given that CRS occurring with tarlatamab has been characterized as mostly grade 1 and 2 in nature,3 our institution implemented a hybrid observation model starting in August 2024.
OBJECTIVE: To characterize our experience using a hybrid oncology administration model for tarlatamab, including patient demographics, safety outcomes (American Society for Transplantation and Cellular Therapy consensus grading), and length of stay information.
METHODS: In this retrospective chart review, tarlatamab was infused in patients in an outpatient setting, and patients were subsequently observed in the inpatient unit for CRS and ICANS monitoring and management.
RESULTS: From August 2024 to October 2025, there were 19 administrations of tarlatamab using this hybrid observation model. The median age of patients was 64 years (interquartile range [IQR], 61-68) with a median length of stay of 24 hours (IQR, 23-27). A total of 8 of the 19 observation stays involved the management of CRS and/or ICANS. Only 2 observations had to be extended into full inpatient encounters. CRS of any grade was observed in 40% of patients with either of the first 2 doses. All cases of CRS were grade 1 or 2. The incidence of CRS was found to be higher with dose 1 than dose 2, at 30% versus 13%, respectively. ICANS of any grade was observed in 40% of patients with either of the first 2 doses. The incidence of ICANS was similar with dose 1 and dose 2, at 30% and 25%, respectively. There were no cases of grade 3 or 4 ICANS.
CONCLUSION: A hybrid observation model can be safely used for oncology patients receiving tarlatamab to monitor for and manage CRS and ICANS. This allows for improved patient satisfaction and the ability to appropriately charge for these ambulatory services.
- Imdelltra (tarlatamab-dlle) [prescribing information]. Amgen, Inc; May 2024.
- Mountzios G, Sun L, Cho BC, et al. Tarlatamab in small-cell lung cancer after platinum-based chemotherapy. N Engl J Med. 2025;393:349-361. doi:10.1056/NEJMoa2502099
- Ahn M-J, Cho BC, Felip E, et al. Tarlatamab for patients with previously treated small-cell lung cancer. N Engl J Med. 2023;389:2063-2075. doi:10.1056/NEJMoa2307980