> ## Content Index
> Fetch the complete content index at: https://www.fdaweb.com/llms.txt
> Use this file to discover other available public pages before exploring further.

# Omeros BLA Resubmission for Narsoplimab
- URL: https://www.fdaweb.com/omeros-bla-resubmission-for-narsoplimab/
- Published: 2025-05-07T12:00:00.000Z
- Updated: 2026-09-14T15:11:15.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5159135

FDA has accepted for review an Omeros BLA resubmission for narsoplimab for treating hematopoietic stem cell transplant-associated thrombotic microangiopathy (TA-TMA). The resubmission has been assigned a user fee review action target date of late September.

In 2021, FDA issued a complete response letter on the BLA, saying it had difficulty in estimating narsoplimab’s treatment effect and requesting additional information to support approval, according to the company. It also said there were no chemistry, manufacturing and controls, safety, or non-clinical issues standing in the way of approval.

The resubmission includes the primary set of analyses comparing overall survival for narsoplimab-treated patients to overall survival for an external control group of TA-TMA patients. “Results of those analyses showed clinically meaningful and statistically significant improvements in survival associated with narsoplimab treatment,” Omeros says. Also included in the resubmission are data describing survival in Omeros’ expanded access program.

Narsoplimab is designed to target mannan-binding lectin-associated serine protease-2, the effector enzyme of the lectin pathway of complement.