As reported in the Journal of Clinical Oncology by Dowlati et al, extended follow-up of the phase I DeLLphi-300 trial has shown sustained benefit with tarlatamab, a bispecific T-cell engager immunotherapy targeting delta-like ligand 3, in patients with previously treated small cell lung cancer.
Study Details
In the international study, 152 patients received tarlatamab at ≥ 10 mg every 2 weeks, once every 3 weeks, or once on day 1 and once on day 8 of 21-day cycles. The recommended phase II dose was 10 mg every 2 weeks. The current report represents findings at a median follow-up of 12.1 months (range = 0.2–34.3 months).
Key Findings
Among all patients, the objective response rate was 25.0%, median duration of response was 11.2 months (95% confidence interval [CI] = 6.6–22.3 months), and median overall survival was 17.5 months (95% CI = 11.4 months to not estimable).
Among 17 patients receiving the recommended phase II dose of 10 mg once every 2 weeks, the objective response rate was 35.3%, median duration of response was 14.9 months (95% CI = 3.0 months to not estimable), median overall survival was 20.3 months (95% CI = 5.1 months to not estimable), and 29.4% had sustained disease control at ≥ 52 weeks on treatment.
Among 16 patients with baseline central nervous system lesions ≥ 10 mm, tumor shrinkage of at least 30% was observed in 10 patients (62.5%).
The investigators concluded: “In DeLLphi-300 extended follow-up, tarlatamab demonstrated unprecedented survival and potential findings of intracranial activity in previously treated SCLC.”
Afshin Dowlati, MD, of University Hospitals Seidman Cancer Center and Case Western Reserve University, Cleveland, is the corresponding author of the Journal of Clinical Oncology article.
DISCLOSURE: The study was supported by Amgen. For full disclosures of the study authors, visit ascopubs.org.
