Amgen has announced promising late-stage trial results showing that its immunotherapy drug Imdelltra, when combined with AstraZeneca’s Imfinzi, reduces the risk of death by 58% in patients with extensive-stage small cell lung cancer (SCLC). This aggressive form of lung cancer spreads rapidly beyond the lungs and is notoriously difficult to treat. The combination therapy extended median overall survival to 21.1 months compared to 12.7 months with Imfinzi alone, suggesting a significant improvement in patient outcomes.

The trial focused on using Imdelltra as a maintenance therapy for patients whose cancer had not progressed after initial treatment with Imfinzi and chemotherapy. Dr. Paul Burton, Amgen’s chief medical officer, described the data as potentially transformative, with the combination therapy offering a chance to convert this aggressive cancer into a chronic condition. The positive results were consistent across patient subgroups, including those with brain or liver metastases, which are typically linked to worse prognoses.

Imdelltra’s commercial potential is also notable, as the drug posted $288 million in sales during the second quarter of 2026, reflecting a 115% increase year-over-year. In 2025, Imdelltra generated $627 million globally and is on track to become a blockbuster drug, potentially crossing the $1 billion sales mark. The findings suggest earlier use of Imdelltra in the treatment course could significantly alter the disease trajectory, positioning it as a vital component alongside immunotherapies like Imfinzi in SCLC.

The mechanism behind the drug combo involves Imdelltra directing the immune system’s T cells toward cancer cells by binding to both the DLL3 protein on tumors and CD3 on T cells, while Imfinzi blocks PD-L1 to free immune responses. This complementary approach enhances the immune attack on cancer. Patient stories, like that of Kate Brenan, highlight the hope this treatment offers, as she has experienced no evidence of disease since starting Imdelltra after metastasis. The results were presented at the European Society for Medical Oncology Congress, marking a significant step forward in lung cancer therapy.