On May 16, 2024, the Food and Drug Administration (FDA) gave accelerated approval to Imdelltra (tarlatamab-dlle), developed by Amgen, Inc., for treating extensive stage small cell lung cancer (ES-SCLC) that has progressed despite platinum-based chemotherapy.
In a study called DeLLphi-301 [NCT05060016], which was open-label and involved multiple centers and cohorts, efficacy was assessed in 99 patients with relapsed or refractory ES-SCLC. Patients excluded from the study had symptomatic brain metastases, interstitial lung disease, non-infectious pneumonitis, or active immunodeficiency. Patients were treated with tarlatamab until their disease progressed or they experienced unacceptable side effects.
The main measures of efficacy were the overall response rate (ORR) according to RECIST 1.1 criteria and the duration of response (DOR), evaluated through blinded independent central review. The ORR was 40%, with a median DOR of 9.7 months. Among patients with known platinum sensitivity status, the ORR was 52% for those with platinum-resistant SCLC (defined as progression within 90 days after the last dose of platinum therapy) and 31% for those with platinum-sensitive SCLC (defined as progression at least 90 days after the last dose of platinum therapy).
The prescribing information for tarlatamab-dlle includes a Boxed Warning regarding serious or life-threatening cytokine release syndrome (CRS) and neurologic toxicity, including immune effector cell-associated neurotoxicity syndrome (ICANS). The most commonly reported adverse reactions (occurring in more than 20% of patients) were CRS, fatigue, fever, altered taste, decreased appetite, musculoskeletal pain, constipation, anemia, and nausea. The most common Grade 3 or 4 laboratory abnormalities (occurring in 5% or more of patients) included decreased lymphocytes, decreased sodium, increased uric acid, decreased neutrophils, decreased hemoglobin, increased activated partial thromboplastin time, and decreased potassium.
The recommended dosage for tarlatamab is an initial intravenous infusion of 1 mg over 1 hour on Cycle 1 Day 1, followed by 10 mg on Cycle 1 Day 8 and Day 15, then every 2 weeks thereafter until disease progression or unacceptable toxicity.
References:
https://www.fda.gov/drugs/resources-information-approved-drugs/fda-grants-accelerated-approval-tarlatamab-dlle-extensive-stage-small-cell-lung-cancer
FDA Approval
