FDA approves efficacy supplement for UCB's Zilbrysq

The U.S. Food and Drug Administration approved an efficacy supplement for Zilbrysq, a product sponsored by UCB Inc, with a submission status date of October 15, 2026. The record lists the submission class as efficacy, submission number 15, with an approval status, under application number NDA216834.¹

The approval letter tied to this action is dated October 19, 2026, according to the FDA's drug application documents.

Zilbrysq is formulated as zilucoplan sodium in a subcutaneous solution. The approved product line includes three strengths: 23 mg base per 0.574 mL, 32.4 mg base per 0.81 mL, and 16.6 mg base per 0.416 mL.¹

The FDA classified the review as standard priority rather than priority review. The submission type is listed as SUPPL, meaning a supplemental application to the original NDA, and the submission status is marked AP for approved.¹

The filing does not specify the clinical indication or data supporting this efficacy supplement beyond the administrative record. Readers seeking the underlying clinical rationale, trial data, or label changes associated with this supplement should consult the full approval letter posted at the FDA's drug application file for NDA216834, submission 15, which was made available on October 19, 2026.