Bispecific T-cell engager for ES-SCLC

At ASCO 2025, Prof Dr Karim Vermaelen, a thoracic oncologist at Ghent University Hospital, discussed the interim analysis of the Phase 3 trial exploring tarlatamab, a bispecific T-cell engager, in patients with extensive-stage small cell lung cancer (ES-SCLC) who had relapsed after first-line therapy. The results were highly impressive, demonstrating significant improvements across all key measures, including PFS, OS, response rate, and patient-reported outcomes, such as symptom relief. Tarlatamab resulted in a 40% reduction in the probability of death, outperforming the current standard of care, single-agent chemotherapy, which is toxic and has poor response rates.

Prof Dr Vermaelen, also a principal investigator at one of the few centers in Belgium participating in the trial, highlighted the unprecedented responses seen in this difficult-to-treat population. While concerns about the toxicity profile initially arose, the results indicated that the side effects were manageable and aligned with the study’s findings, with most toxicities being mild. He noted that although the toxicity patterns, especially neurological effects, will require proper recognition by physicians, the overall benefits for patients far outweigh the risks. He expressed optimism that, much like with immune checkpoint inhibitors, the medical community would eventually become adept at managing these side effects, and the benefits of tarlatamab would greatly improve patient outcomes. 

This data suggests that tarlatamab could significantly change the treatment landscape for patients with relapsed ES- SCLC.