On October 15, 2025, Novo Nordisk and Omeros Corporation announced that they have entered into a definitive asset purchase and license agreement for the candidate drug zaltenibart (OMS906) in clinical development for rare blood and kidney disorders. Wilson Sonsini Goodrich & Rosati advised Omeros on the transaction.

Zaltenibart is an antibody designed to inhibit MASP-3, a protein that acts as a key activator of the complement system’s alternative pathway. Under the terms of the agreement, Novo Nordisk will be granted exclusive global rights to develop and commercialize zaltenibart in all indications. Omeros is eligible to receive $340 million in upfront and near-term milestone payments, up to a total of $2.1 billion dollars including potential development and commercial milestones, plus tiered royalties on net sales. The transaction is expected to close by the end of 2025, subject to regulatory approvals and customary closing conditions.

The Wilson Sonsini team that advised Omeros on the transaction includes:

Technology Transactions
Farah Gerdes
Sarah Walker
Alysha O’Hara
Christina Fuleihan 

M&A
Jason Breen
Ross Tanaka
Cassie Wetzel
Zheng Zhou
Ikechi Ngwangwa 

Delaware Law
Erin Fay
Heather Lambert

Corporate Finance
Dana Hall
Bryan King

Data, Privacy, and Cybersecurity
Matt Staples
Michael O’Brien

Tax
Myra Sutanto Shen
Anjali Krishnan

Antitrust and Competition
Michele Yost Hale
Kimberley Biaglioli

National Security
Joshua Gruenspecht
Waqas Shahid
Seth Cowell

FDA Regulatory
Eva Yin

For more information, please see Omeros’ news release. Additional coverage can be found on The Wall Street Journal and Reuters.