The Food and Drug Administration (FDA) has accepted for Priority Review the Biologics License Application (BLA) for omburtamab for the treatment of pediatric patients with central nervous system (CNS)/leptomeningeal metastasis from neuroblastoma. 

Omburtamab is an investigational radiolabeled monoclonal antibody designed to target tumor cells that express B7-H3. The BLA submission is supported by data from 2 clinical studies ( Identifier: 101 [NCT03275402] and 03-133 [NCT00089245]), which evaluated the efficacy and safety of omburtamab in patients with CNS/leptomeningeal metastasis. 

According to a February 2022 data readout from the single-center 03-133 study, patients with CNS/leptomeningeal metastases who received up to 2 doses of omburtamab had a median survival of 50 months, with the final median not yet being reached. The Company expects to publish efficacy and safety data for both studies later this year. 

A Prescription Drug User Fee Act (PDUFA) target date of November 30, 2022 has been set for the application. An FDA advisory committee meeting will be held in October 2022 to discuss the application.

The Company intends to market omburtamab under the trade name Omblastys® pending FDA approval.

“We believe that the FDA’s acceptance of our Omblastys® BLA for priority review is a significant achievement for Y-mAbs and a crucial step forward as we anticipate that Omblastys, if approved by the FDA, can address a significant unmet medical need for children with CNS/leptomeningeal metastasis from high-risk neuroblastoma, where no standard therapy currently exists,” said Thomas Gad, Founder, President and Interim CEO. 

The FDA previously granted Rare Pediatric Disease designation to omburtamab for this indication.


  1. Y-mAbs announces FDA acceptance of Biologics License Application for Omblastys® (omburtamab) for the treatment of neuroblastoma for Priority Review. News release. Y-mAbs Therapeutics, Inc. Accessed May 31, 2022.
  2. Y-mAbs announces submission of omburtamab Biologics License Application to FDA. News release. Y-mAbs Therapeutics, Inc. April 1, 2022. Accessed May 31, 2022.
  3. Y-mAbs announces completion of pre-BLA meeting with FDA for omburtamab. News release. Y-mAbs Therapeutics, Inc. February 11, 2022. Accessed May 31, 2022.