WASHINGTON -- The FDA granted accelerated approval of the plus granulocyte macrophage-colony stimulating factor (GM-CSF) for pediatric and adult patients with certain types of relapsed or refractory neuroblastoma.
The approval applies to neuroblastoma in the bone or bone marrow and that exhibited stable disease or better response to the most recent prior therapy.
The approval was based primarily on results from two single-arm, open-label clinical trials involving a total of 60 patients. In each trial, patients received three naxitamab infusions in combination with GM-CSF during each 4-week cycle. The primary endpoint for both trials was overall response rate (ORR).
The treatment led to an ORR of 45% in 22 patients, and 30% of responses lasted 6 months or longer. In the second trial, 34% of 38 patients responded to naxitamab and GM-CSF, and 23% of responses lasted for at least 6 months.
Prescribing information for naxitamab included a boxed warning about a risk of serious infusion-related reactions and neurotoxicity, including neuropathic pain, transverse myelitis, and reversible posterior leukoencephalopathy syndrome. Premedication prior to infusion can reduce the risk.
Naxitamab is directed against disialoganglioside (GD2), a cell-surface antigen expressed by neuroectoderm-derived tumors, sarcomas, and embryonal tumors. FDA granted the conditional approval to Y-mAbs Therapeutics. Prior to final approval, the sponsor may have to provide additional data to confirm the initial safety and efficacy findings.