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Clinical Trial
. 2025 Apr;10(4):104538.
doi: 10.1016/j.esmoop.2025.104538. Epub 2025 Apr 4.

Safety of tarlatamab with 6-8-h outpatient versus 48-h inpatient monitoring during cycle 1: DeLLphi-300 phase 1 substudy

A C Chiang  1 , M E Olmedo Garcia  2 , J W Carlisle  3 , A Dowlati  4 , N Reguart  5 , E Felip  6 , P J Jost  7 , N Steeghs  8 , R Stec  9 , S M Gadgeel  10 , H H Loong  11 , W Jiang  12 , A Hamidi  12 , A Parkes  12 , L Paz-Ares  13
Affiliations
Clinical Trial

Safety of tarlatamab with 6-8-h outpatient versus 48-h inpatient monitoring during cycle 1: DeLLphi-300 phase 1 substudy

A C Chiang et al. ESMO Open. 2025 Apr.

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.

Keywords: adverse events; cytokine release syndrome; outpatient; patient monitoring; safety; small-cell lung cancer; tarlatamab.

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References

    1. Rudin C.M., Reck M., Johnson M.L., et al. Emerging therapies targeting the delta-like ligand 3 (DLL3) in small cell lung cancer. J Hematol Oncol. 2023;16(1):66. - PMC - PubMed
    1. Giffin M.J., Cooke K., Lobenhofer E.K., et al. AMG 757, a half-life extended, DLL3-targeted bispecific T-cell engager, shows high potency and sensitivity in preclinical models of small-cell lung cancer. Clin Cancer Res. 2021;27(5):1526–1537. - PubMed
    1. Dhillon S. Tarlatamab: first approval. Drugs. 2024;84(8):995–1003. - PubMed
    1. Paz-Ares L., Champiat S., Lai W.V., et al. Tarlatamab, a first-in-class DLL3-targeted bispecific T-cell engager, in recurrent small-cell lung cancer: an open-label, phase I study. J Clin Oncol. 2023;41(16):2893–2903. - PMC - PubMed
    1. Ahn M.J., Cho B.C., Felip E., et al. Tarlatamab for patients with previously treated small-cell lung cancer. N Engl J Med. 2023;389(22):2063–2075. - PubMed

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