Korean patients with small cell lung cancer (SCLC) may soon gain access to a groundbreaking treatment option as Amgen's tarlatamab advances through regulatory review. The bispecific antibody therapy, marketed as Imdelltra in the United States, has already demonstrated promising results through its therapeutic use program in Korea, with 93 cases reported since May 2023.
The innovative treatment represents a significant advancement in SCLC therapy, particularly for patients who have experienced disease progression following platinum-based chemotherapy. Tarlatamab operates through a novel mechanism of action as a bispecific T-cell engaging antibody (BiTE), targeting delta-like ligand 3 (DLL3) on cancer cells while simultaneously engaging CD3 on T-cells, effectively mobilizing the immune system against the cancer.
Korean Leadership in Clinical Development
Korean researchers played a pivotal role in tarlatamab's development pathway. Professor Ahn Myung-ju of Samsung Medical Center's Department of Hematology-Oncology served as the lead author of the crucial phase 2 DeLLphi-301 study, which ultimately supported the FDA's accelerated approval decision in May 2024. This study was instrumental in establishing the optimal dosing regimen for the therapy.
The ongoing phase 3 DeLLphi-304 trial, designed as a confirmatory study for full FDA approval, further emphasizes Korea's significance in tarlatamab's clinical program. The trial, comparing tarlatamab to standard of care in post-platinum-chemotherapy SCLC patients, will include the largest Asian cohort in Korea, with approximately 400 patients expected to participate.
Addressing Critical Treatment Gaps
SCLC, comprising 10-15 percent of all lung cancer cases, is characterized by rapid metastasis and poor prognosis compared to non-small cell lung cancer. The current treatment landscape in Korea offers limited options, with only Imfinzi (dervalumab) and Zepzelca (lurbinectetin) approved for extended-stage SCLC. However, these treatments remain outside the national health insurance coverage, creating significant financial barriers for patients.
Regulatory Timeline and Market Impact
Amgen Korea has submitted its regulatory application to the Ministry of Food and Drug Safety, with approval anticipated in the first half of 2024. The therapy's potential introduction comes at a crucial time, supported by robust clinical data and successful therapeutic use cases in the Korean population.
The FDA's accelerated approval of tarlatamab in May 2024 marked a historic milestone as the first therapy specifically approved for treating SCLC in the United States. This regulatory precedent, combined with strong local clinical evidence and unmet medical need, positions tarlatamab as a potentially transformative addition to Korea's SCLC treatment arsenal.
