Tarlatamab Continues to Elicit Responses in Patients With SCLC

Extended follow-up from the phase 2 DeLLphi-301 study (NCT05060016) showed that tarlatamab-dlle (Imdelltra) led to sustained anticancer activity and manageable safety in patients with extended-stage small cell lung cancer previously treated with platinum-based chemotherapy. These data were presented at the 2024 World Conference on Lung Cancer.^1,2

At a median follow-up of 13.6 months (range, 0.1-20.9) for efficacy evaluation, the overall response rate (ORR) was 40.4% and the median duration of response was not estimable in patients receiving the 10 mg dose. Responses were ongoing in 47.5% (n = 19) of responders. The median progression-free survival was 4.3 months, and the median overall survival (OS) was 15.2 months. The 6- and 12-month estimated OS rates were 73.4% and 56.7%, respectively.

The study evaluated both 10-mg and 100-mg dose levels, with the 10-mg dose selected as the appropriate choice for subsequent trials.

No new safety signals were identified, and the most common adverse event (AE) was cytokine release syndrome (CRS; 56.8%). Most events were grade 1 or 2, with no grade 4 or 5 events. Only 2.7% of patients discontinued treatment due to treatment-related AEs.

In May 2024, the FDA approved the bispecific T-cell engager (BiTE) tarlatamab in this patient population based on the DeLLphi-301 study, making it the first BiTE therapy to be approved for the treatment of a major solid tumor.³ Findings from the primary analysis were published in The New England Journal of Medicine and presented at the 2023 European Society of Medical Oncology Congress.

Here, the ORR for patients treated with the 10 mg dose of tarlatamab was 40% (97.5% CI, 29%-52%). Fifty-eight percent of patients in the 10-mg group responded to tarlatamab for at least 6 months.^4,5 CRS occurred in 49% of patients in the 10 mg group, primarily during the first cycle and mostly grade 1 or 2.

REFERENCES:

1. Sands J, Cho BC, Ahn MJ, et al. Tarlatamab sustained clinical benefit and safety in previously treated SCLC: DeLLphi-301phase 2 extended follow-up. Presented at: 2024 World Conference on Lung Cancer; September 7-10, 2024; San Diego, CA. Abstract OA10.03.

2. Amgen presents new data for first-in-class IMDELLTRA™ (tarlatamab-dlle) in small cell lung cancer at WCLC 2024. News release. Amgen. September 9, 2024. Accessed September 9, 2024. https://tinyurl.com/mpn27pa7

3. FDA grants accelerated approval to tarlatamab-dlle for extensive stage small cell lung cancer. News release. FDA. May 16, 2024. Accessed September 9, 2024. https://tinyurl.com/bddwjpk2

4. Paz-Ares L, Ahn M, Felip E, et al. Tarlatamab for patients (pts) with previously treated small cell lung cancer (SCLC): Primary analysis of the phase II DeLLphi-301 study. Presented at: European Society for Medical Oncology Congress 2023; October 20-24, 2023; Madrid, Spain. Abstract LBA92.

5. Ahn MJ, Cho BC, Felip E, et al. Tarlatamab for patients with previously treated small-cell lung cancer. N Engl J Med. 2023;389(22):2063-2075. doi:10.1056/NEJMoa2307980