Tarlatamab is a first-in-class bispecific T-cell engager (BiTE) that binds delta-like ligand 3 on the surface of cells, including tumor cells, and CD3 expressed on the surface of T cells. It causes T-cell activation, release of inflammatory cytokines, and lysis of DLL3-expressing cells, according to labeling.
Approval was based on data from 99 patients in the DeLLphi-301 trial with relapsed/refractory extensive-stage SCLC who had progressed after platinum-based chemotherapy. Patients with symptomatic brain metastases, interstitial lung disease, noninfectious pneumonitis, and active immunodeficiency were excluded.
The overall response rate was 40%, and median duration of response 9.7 months. The overall response rate was 52% in 27 patients with platinum-resistant SCLC and 31% in 42 with platinum-sensitive disease.
Continued approval may depend on verification of clinical benefit in a confirmatory trial.
Labeling includes a box warning of serious or life-threatening cytokine release syndrome and neurologic toxicity, including immune effector cell–associated neurotoxicity syndrome.
The most common adverse events, occurring in 20% or more of patients, were cytokine release syndrome, fatigue, pyrexia, dysgeusia, decreased appetite, musculoskeletal pain, constipation, anemia, and nausea.
The most common grade 3 or 4 laboratory abnormalities included decreased lymphocytes, decreased sodium, increased uric acid, decreased total neutrophils, decreased hemoglobin, increased activated partial thromboplastin time, and decreased potassium.
The starting dose is 1 mg given intravenously over 1 hour on the first day of the first cycle followed by 10 mg on day 8 and day 15 of the first cycle, then every 2 weeks until disease progression or unacceptable toxicity.
M. Alexander Otto is a physician assistant with a master’s degree in medical science and a journalism degree from Newhouse. He is an award-winning medical journalist who worked for several major news outlets before joining Medscape. Alex is also an MIT Knight Science Journalism fellow. Email: aotto@mdedge.com
A version of this article appeared on Medscape.com.