Abcuro Secures $200M Series C Funding for Pivotal KLRG1 Antibody Trial

Abcuro, a biotechnology company backed by pharmaceutical giant Sanofi, has successfully raised $200 million in a Series C funding round. This significant financial boost is earmarked to support the company's pivotal phase 2/3 clinical trial for its anti-KLRG1 antibody, ulviprubart (ABC008), in treating inclusion body myositis (IBM).

Ulviprubart: A Novel Approach to Autoimmune Disease Treatment

Ulviprubart represents a unique approach in the field of autoimmune disease therapeutics. Unlike competitors targeting CD25, CD2, CD52, and ICOS, Abcuro's strategy focuses on KLRG1, a protein expressed primarily on highly cytotoxic late-differentiated effector memory and effector T cells. The company's rationale is that by targeting KLRG1, ulviprubart can selectively deplete the cells driving autoimmune diseases while preserving regulatory T cells and central memory T cells.

This selective mechanism is particularly relevant for IBM, a muscle-wasting disease affecting approximately 50,000 individuals across the United States and Europe. IBM is characterized by T-cell attacks on muscle fibers, leading to a loss of hand function and mobility. The connection between KLRG1-expressing T cells and IBM was established in a 2019 paper co-authored by Dr. Steven Greenberg, a neurologist at Brigham and Women's Hospital and Abcuro's founder.

Clinical Development and Commercial Preparations

The newly secured funds will primarily support the ongoing phase 2/3 trial of ulviprubart in IBM patients. Abcuro has set ambitious goals, with plans to file for FDA approval if the trial yields positive results, expected in the first half of 2026.

Alex Martin, CEO of Abcuro, emphasized the significance of this funding round, stating, "Continued support from all of our investors in this latest financing round validates our vision for the potential that ulviprubart may have as a novel treatment for progressive and devastating diseases mediated by highly cytotoxic T cells, including inclusion body myositis."

Beyond the IBM trial, Abcuro is also conducting a phase 1/2 clinical trial of ulviprubart in T-cell large granular lymphocytic leukemia, further exploring the potential applications of their KLRG1-targeting approach.

A portion of the Series C funds will be allocated to prepare for a potential commercial launch of ulviprubart and to expand the company's manufacturing capabilities. This forward-looking strategy underscores Abcuro's confidence in ulviprubart's potential and their commitment to bringing this novel treatment to market.

Investor Confidence and Future Prospects

The Series C round was led by New Enterprise Associates, with participation from new investor Foresite Capital. The funding also saw continued support from previous backers, including Sanofi Ventures, RA Capital, Bain Capital Life Sciences, Redmile Group, Samsara BioCapital, Pontifax, Mass General Brigham Ventures, New Leaf Ventures, and funds and accounts managed by BlackRock.

This robust investor lineup, featuring both new and returning supporters, reflects strong confidence in Abcuro's scientific approach and commercial potential. The company's journey from its initial Series A-1 round, overseen by Mass General Brigham Ventures and Sanofi Ventures in 2021, to its substantial $155 million Series B in 2023, and now this $200 million Series C, illustrates a trajectory of growing investor interest and support for Abcuro's innovative approach to treating autoimmune diseases.