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# FDA Questions Y-mAbs Neuroblastoma Treatment Efficacy
- URL: https://www.fdaweb.com/fda-questions-y-mabs-neuroblastoma-treatment-efficacy/
- Published: 2022-10-27T12:00:00.000Z
- Updated: 2026-09-14T18:04:27.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5153067

FDA medical reviewers say they are unable to establish a substantive risk/benefit relationship for using Y-mAbs Therapeutics’ I-omburtamab in pediatric patients with CNS/leptomeningeal metastases from neuroblastoma. The reviewers raised their concerns in a [briefing paper](https://www.fda.gov/media/162614/download?ref=fdaweb.com) released in advance of a 10/28 meeting of the Oncologic Drugs Advisory Committee to discuss the company’s BLA, which has a PDUFA action date of 11/30.

The Y-mAbs BLA is seeking traditional approval for an indication to treat central nervous system (CNS)/leptomeningeal metastases in pediatric patients with neuroblastoma following standard multimodality treatment for CNS disease.

The medical reviewers identified these issues with the application:

- the external control population is not fit-for-purpose as a comparator due to substantive differences between the study and control populations that limit the ability to attribute survival differences to the effect of the drug;
- recognizing the level of evidence provided and the need for regulatory flexibility, FDA performed additional analyses to examine bias and those results reinforce that differences in survival cannot be reliably attributed to I-omburtamab; and
- the application does not include reliable response rate data to provide supportive evidence of the drug’s treatment effect.