FDA Approves Amgen's BiTE Imdelltra for Small-Cell Lung Cancer

The FDA has granted accelerated approval to Amgen's Imdelltra (tarlatamab-dlle) for the treatment of certain lung cancer patients, ahead of its mid-June deadline. Imdelltra, a bispecific T-cell engager (BiTE) that targets DLL3 and CD3, will come with a boxed warning for cytokine release syndrome and neurological toxicities, including immune effector cell-associated neurotoxicity syndrome. This approval specifically targets patients with extensive-stage small-cell lung cancer (ES-SCLC) who have experienced disease progression on or after platinum-based chemotherapy.

This accelerated approval is based on the results of the Phase II DeLLphi-301 study. The study demonstrated that Imdelltra achieved an overall response rate of 40% in 99 patients with relapsed or refractory ES-SCLC. The median duration of response was noted to be 9.7 months. Such results indicate that Imdelltra could be a significant addition to the existing treatment options for SCLC, which have seen limited advancements over the years.

Sawsan Rashdan, a lung cancer specialist and assistant professor at the University of Texas Southwestern Medical Center, noted the importance of any treatment that surpasses historical controls, like topotecan, which has a progression-free survival (PFS) benefit of merely three to four months. Rashdan commented that while Imdelltra's PFS benefit of 3.7 months is not significantly better than historical controls, the overall survival benefit of 13 months is promising. This sentiment reflects a cautious optimism within the medical community regarding Imdelltra's potential impact on SCLC treatment.

Imdelltra represents the first BiTE approved for a major solid tumor indication, marking a significant milestone for Amgen. The company has a history of pioneering T-cell engaging antibodies, beginning with the approval of Blincyto (blinatumomab) in 2014 for B-cell precursor acute lymphoblastic leukemia. Blincyto has since experienced a surge in sales, becoming Amgen’s fastest-growing product and signaling the potential for future successes with Imdelltra.

The approval process for Imdelltra was expedited through both the FDA’s priority review and real-time oncology review pathways, underscoring the urgent need for new treatments for ES-SCLC. While the boxed warnings for severe side effects like cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome indicate that Imdelltra must be used with caution, its approval provides a new option for patients who have exhausted other treatments.

Amgen's development of Imdelltra reflects its ongoing commitment to innovation in oncology, particularly in addressing unmet needs in cancer treatment. The introduction of BiTE technology for solid tumors could pave the way for further advancements in the field, offering hope to patients with limited treatment options.

In summary, the accelerated approval of Imdelltra marks a significant development in the treatment of extensive-stage small-cell lung cancer. While its side effects warrant careful monitoring, its potential benefits could provide a much-needed option for patients facing disease progression after traditional chemotherapy. The medical community remains hopeful that Imdelltra will improve survival outcomes for these patients, continuing Amgen's legacy of pioneering novel cancer therapies.