Amgen's bispecific antibody tarlatamab (Imdelltra), a treatment for small cell lung cancer (SCLC), is garnering significant interest from Korean physicians and patients. The drug has already seen 93 cases of therapeutic use in Korea following its first approval for therapeutic use on May 29 last year, highlighting the urgent need for new SCLC treatments.
Tarlatamab is a bispecific T-cell engaging antibody (BiTE) therapy. It works by binding to delta-like ligand 3 (DLL3), which is expressed on cancer cells, and CD3 on T-cells. This dual binding activates T-cells, enabling them to directly target and destroy SCLC cells that express DLL3.
FDA Approval and Clinical Data
In May 2024, the U.S. Food and Drug Administration granted accelerated approval to tarlatamab monotherapy for adult patients with expanded-stage small cell lung cancer (ES-SCLC) whose disease progressed during or after platinum-based chemotherapy. This approval was based on encouraging response rates and duration of response observed in early clinical trials.
Professor Ahn Myung-ju of the Department of Hematology-Oncology at Samsung Medical Center played a pivotal role in the development of tarlatamab. As the first author of the phase 2 DeLLphi-301 study, Professor Ahn's work was instrumental in securing FDA approval and determining the approved dose of the drug.
Ongoing Phase 3 Trial
Amgen is currently conducting a randomized, open-label phase 3 study (DeLLphi-304) to compare tarlatamab to the standard of care in patients with SCLC who have relapsed after first-line platinum-based chemotherapy. This confirmatory trial for full FDA approval is expected to enroll approximately 400 patients in Korea, the largest number in Asia, indicating the importance of Korean data in assessing tarlatamab's efficacy.
SCLC Treatment Landscape in Korea
SCLC accounts for 10-15% of all lung cancers and is characterized by rapid metastasis and poor prognosis compared to non-small cell lung cancer (NSCLC). Currently, treatment options in Korea are limited. While immuno-oncology drugs like Imfinzi (durvalumab) and chemotherapy drugs like Zepzelca (lurbinectedin) are approved for extended-stage SCLC, they are not covered by health insurance, creating a significant financial burden for patients.
Tarlatamab represents a promising new treatment option, especially given the robust clinical data involving Korean researchers and the FDA's expedited approval. Amgen Korea submitted an application to the Ministry of Food and Drug Safety for tarlatamab approval last year and anticipates a decision in the first half of this year, which could significantly improve the treatment landscape for SCLC patients in Korea.
