FDA approves eflornithine for high-risk neuroblastoma following partial response to prior therapy.

By: Dr. Anish Shah
Bronx-Lebanon Hospital; Bronx, NY

On December 13, 2023, the U.S. Food and Drug Administration granted approval to eflornithine (IWILFIN, USWM, LLC) for adult and pediatric patients with high-risk neuroblastoma (HRNB) who have demonstrated at least a partial response to prior multiagent, multimodality therapy including anti-GD2 immunotherapy. This is the first FDA approval of a therapy intended to reduce the risk of relapse in
pediatric patients with HRNB.

Study ID: NCT02395666

The effectiveness of the treatment was assessed by comparing results from two separate trials: Study 3b (the experimental group) and Study ANBL0032 (the control group based on clinical trial data). Study 3b
involved several medical centers and was not randomized. It consisted of two groups, with 105 qualified high-risk neuroblastoma (HRNB) patients in one group (Stratum 1). These patients were given eflornithine orally, twice a day, with the dosage adjusted according to their body size. The treatment continued until the disease progressed, side effects became intolerable, or for a maximum of two years. The results of Study 3b were deliberately designed to be compared with the event-free survival rate from Study ANBL0032, a standard rate from previously published research.

Efficacy was established on event free survival (EFS), defined as disease progression, relapse, secondary cancer, or death due to any cause, and overall survival (OS), defined as death due to any cause. In the primary analysis, the EFS hazard ratio (HR) was 0.48 (95% CI: 0.27, 0.85) and OS HR was 0.32 (95% CI: 0.15, 0.70). Results of the study indicate a significant reduction in the risk of relapse in patients treated with eflornithine compared to control patients from Study ANBL0032.

The most common adverse reactions (≥5%) in Study 3b, including laboratory abnormalities, were otitis media, diarrhea, cough, sinusitis, pneumonia, upper respiratory tract infection, conjunctivitis, vomiting,
pyrexia, allergic rhinitis, decreased neutrophils, increased ALT, increased AST, hearing loss.

The FDA has approved eflornithine for adult and pediatric patients with high-risk neuroblastoma who have demonstrated at least a partial response to prior therapy. The medication is to be administered orally, twice a day, at a dosage based on body surface area until disease progression, unacceptable toxicity, or for a maximum of 2 years.