Analysis of 90 patients with small cell lung cancer found mostly low-grade cytokine release syndrome and neurotoxicity across outpatient, inpatient, and hybrid care models

NASHVILLE, Tenn., Oct. 27, 2026 /PRNewswire/ — OneOncology today announced results from a real-world retrospective study of the delivery of tarlatamab, a treatment for extensive-stage small cell lung cancer (ES-SCLC), across community oncology practices. The findings, presented (Poster 6409, FPN) at the 2026 European Society for Medical Oncology (ESMO) Congress in Madrid, demonstrate the feasibility of administering tarlatamab in community oncology practices. 

Tarlatamab is a bispecific T-cell engager immunotherapy that targets delta-like ligand 3 (DLL3) and the cluster of differentiation 3 (CD3). Because it can cause cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), patients historically needed to be monitored in a health care setting for nearly a full day when treatment begins, which can place a significant burden on patients and on community practices working to bring advanced therapies closer to home.

The U.S. Food and Drug Administration (FDA) approved a September 2026 update to the tarlatamab prescribing information, which shortened the recommended observation period after the first two doses from 22–24 hours to 6–8 hours. The updated requirement reduces treatment complexity for community oncology practices, where many people with cancer receive care.

“The real-world results give us greater confidence that tarlatamab can be delivered outside the traditional inpatient setting in appropriately selected patients,” said Trevor Feinstein, MD, of Piedmont Cancer Institute, lead author of the abstract.

The retrospective study reviewed 90 patients who started tarlatamab between May 2024 and December 2025 at OneOncology partner practices, with 30 patients each in three care models: outpatient (administered and monitored entirely in the practice infusion center), inpatient (administered and monitored during a planned hospital observation), and hybrid (administered in the infusion center, followed by an observation admission).

Overall, 46% of patients experienced CRS and 14% experienced ICANS. Events were mostly low grade: only 1% of patients had grade 3 or higher CRS, and 2% had grade 3 or higher ICANS. Any-grade CRS occurred in 30% of outpatient, 47% of inpatient, and 60% of hybrid patients, and every CRS event in the outpatient cohort was grade 1. ICANS occurred in 13%, 7%, and 23% of patients, respectively.

In the outpatient model, patients received premedication with dexamethasone and IV fluids and were monitored by nursing staff in the practice infusion center for 4–8 hours after the step-up doses.

Three patients overall (3%) required intensive care unit-level care, and no patients in any cohort were readmitted for any cause. Only one patient, in the hybrid cohort, discontinued tarlatamab because of CRS.

Patients in the hybrid cohort had a higher disease burden at baseline, including more brain metastases (67% vs. 50% outpatient and 57% inpatient), and more liver metastases (77% vs. 50% for both other cohorts). In an exploratory analysis, high metastatic burden and the presence of liver or brain metastases were more common among patients who experienced CRS or ICANS. Given the small sample, these observations are hypothesis-generating.

“This study is an important demonstration of the feasibility of administering outpatient tarlatamab in community oncology practices. These findings can serve as a starting point for expanding access to novel therapies in community oncology practices,” said Wade Iams, MD, MSCI, of Tennessee Oncology.

The authors note that the study is retrospective and not randomized, so care setting may have been influenced by patient characteristics, disease burden, and clinical judgment. The cohort was small, and event capture depended on medical record documentation. Longer follow-up and prospective studies are needed to further define patient selection for outpatient tarlatamab administration.

“In this real-world community oncology cohort, outpatient and hybrid tarlatamab administration was feasible, with most CRS and ICANS events being low grade and manageable,” the authors concluded. “Baseline patient characteristics and disease burden may help inform selection of patients for outpatient monitoring.”

ABOUT THE STUDY

Real-World Safety and Outcomes of Outpatient, Inpatient, and Hybrid Tarlatamab Administration in Relapsed/Refractory Small Cell Lung Cancer. Authors: Trevor Feinstein, MD; Lisa Raff; Michelle Kristalyn; Joseph Abrams; Brenda Simpson; Vanessa Mirsky; Amanda Deleon; CJ Barisonek; Jessica Oliver; Lori Jamison; and Wade Iams, MD, MSCI. Data were drawn from the electronic medical records of OneOncology partner practices.

About OneOncology
OneOncology was founded by community physicians, for community physicians, with the mission of improving the lives of everyone living with cancer and other diseases. Our goal is to enable community medical practices to remain independent and to improve patient access to world-class care in their communities. OneOncology supports our platform of independent medical practices through access to services and expertise including clinical innovation, AI-enabled analytics and RCM, practice growth enablement, and operational optimization.  Our partner practices care for approximately 1.5 million patients across 21 states. To learn more, visit oneoncology.com. 

View original content to download multimedia:https://www.prnewswire.com/news-releases/real-world-data-from-oneoncology-practices-show-tarlatamab-can-be-administered-safely-in-the-outpatient-community-oncology-setting-302921197.html

SOURCE OneOncology, LLC.