May 20, 2024—Amgen announced FDA approval of Imdelltra (tarlatamab-dlle) for the treatment of adult patients with extensive-stage small cell lung cancer with disease progression on or after platinum-based chemotherapy. Imdelltra is a first-in-class immunotherapy that binds to DLL3 on tumor cells and CD3 on T cells, activating T cells to kill DLL3-expressing SCLC cells. This results in the formation of a cytolytic synapse with lysis of the cancer cell. DLL3 is a protein that is expressed on the surface of SCLC cells in about 85 to 96 percent of patients with SCLC but is minimally expressed on healthy cells.
“The FDA’s approval of Imdelltra marks a pivotal moment for patients battling ES-SCLC. This DLL3-targeting therapy in ES-SCLC comprises a transformative option demonstrating long-lasting responses in pretreated patients,” Jay Bradner, MD, EVP of research and development and chief scientific officer at Amgen, said in a press release. “This approval further demonstrates our commitment to addressing aggressive cancers through our second FDA-approved bispecific T-cell engager molecule. Imdelltra offers these patients who are in urgent need of new innovative therapies hope, and we’re proud to deliver this long-awaited effective treatment to them.”
The FDA accelerated approval of Imdelltra is based on results from the phase 2 DeLLphi-301 clinical trial that evaluated the drug in patients with SCLC who had failed two or more prior lines of treatment and who had received a dosing regimen of 10 mg every two weeks. Results from the study found that Imdelltra at that dosing regimen (n=99) demonstrated a robust objective response rate of 40 percent (95 percent confidence interval [CI], 31–51) and median duration of response of 9.7 months (95 percent CI, 2.7–20.7+). The median overall survival was 14.3 months, with final and complete survival data yet to mature. Continued approval for this indication may be contingent on the verification and description of clinical benefit in confirmatory trials.