Amgen has announced landmark results from its Phase 3 DeLLphi-305 study, marking a significant breakthrough in the treatment of small cell lung cancer.
The trial met its primary endpoint at a pre-specified interim analysis, demonstrating a statistically significant and clinically meaningful improvement in overall survival with Imdelltra.
Imdelltra, also known as tarlatamab-dlle, was tested in combination with AstraZeneca’s Imfinzi, known generically as durvalumab, against durvalumab alone.
The study focused on Imdelltra as a first-line maintenance treatment for patients with extensive stage small cell lung cancer whose disease had not progressed after initial induction therapy.
Those patients had previously received durvalumab alongside platinum-based chemotherapy and etoposide before entering the maintenance phase of the trial.
DeLLphi-305 randomised 563 patients on a one-to-one basis, representing a substantial and statistically robust patient population for the analysis.
Notably, this is the first Phase 3 study featuring a Bispecific T-cell Engager therapy to demonstrate an overall survival benefit, a milestone in oncology drug development.
The study also showed statistically significant and clinically meaningful improvements in both progression-free survival and objective response rate among patients receiving the combination treatment.
The safety profile of Imdelltra combined with durvalumab remained consistent with the known profiles of each individual medicine, with no new or unexpected safety signals identified.
Amgen and AstraZeneca have said they plan to present the detailed DeLLphi-305 results at a forthcoming medical meeting and share findings with global regulatory authorities.
Imdelltra is a first-in-class immunotherapy engineered by Amgen that binds to DLL3 on tumour cells and CD3 on T cells, activating T cells to destroy DLL3-expressing small cell lung cancer cells.
DLL3 is a protein expressed on the surface of small cell lung cancer cells in approximately 85 to 96 percent of patients, while remaining minimally present on healthy cells.
If the interim survival benefit is confirmed, Imdelltra plus Imfinzi could establish a new standard maintenance treatment option following first-line induction for extensive stage small cell lung cancer patients.
The results extend Amgen’s DLL3-directed therapeutic approach into an earlier stage of treatment, while building on AstraZeneca’s established immunotherapy backbone in a notoriously difficult-to-treat cancer.