AltruBio Secures $225M Series B for Ulcerative Colitis Treatment

San Francisco-based biotechnology firm AltruBio has successfully secured $225 million through an oversubscribed Series B funding round, as announced on Tuesday. This substantial financing aims to advance the company's ulcerative colitis treatment candidate, ALTB-268, into mid-stage clinical trials.

ALTB-268 is a pioneering immune checkpoint enhancer (ICE) PSGL agonist antibody. It is currently undergoing a Phase IIa exploratory biomarker study involving patients with biologic refractory ulcerative colitis (UC). The primary endpoint of clinical remission, measured by a modified Mayo score, is anticipated to be read out in the first half of the upcoming year.

The newly acquired Series B funds are earmarked for supporting the ongoing trial and initiating a Phase IIb study. This future study will focus on achieving clinical remission in both advanced therapy-experienced and treatment-naïve patients with moderate to severe UC. The results of this study are expected to be available in the latter half of 2026.

Earlier Phase I data for ALTB-268 showed promise. In August 2023, AltruBio reported positive topline results, which provided the impetus for moving forward to Phase II studies, despite the initial lack of hard data points.

“With this substantial investment, we are one step closer to bringing our first-in-class, novel immune checkpoint enhancer, ALTB-268, through our ongoing Phase IIa exploratory biomarker study and initiating an additional Phase IIb study while paving the way for potential indication expansion beyond ulcerative colitis,” stated AltruBio CEO Judy Chou.

The funding round was spearheaded by BVF Partners LP, with additional contributions from new investors such as RA Capital Management, Cormorant Asset Management, and Soleus Capital. Existing investors who also participated in the Series B included Blackstone Multi-Asset Investing and aMoon Fund.

Initially known as AbGenomics Holding, the biotech company rebranded to AltruBio in 2020, reflecting a strategic shift in its focus towards autoimmune diseases. Previously, AbGenomics concentrated on oncology but discontinued the Phase I development of one of its cancer candidates.

In 2021, the biotech raised $63 million in a Series A round to advance its work on immunological disease assets. Additionally, the FDA granted fast-track designation for its drug neihulizumab in treating steroid-refractory acute graft-versus-host disease (SR-aGVHD).

AltruBio is not alone in its successful funding endeavors within the immunology sector. In March 2024, precision medicine startup Mirador Therapeutics launched with a substantial $400 million funding to support various therapeutic programs targeting immune-mediated inflammatory and fibrotic diseases. Similarly, earlier this month, Attovia Therapeutics raised $105 million in a Series B round to further develop candidates for treating immune-mediated diseases, atopic dermatitis, and other pruritic conditions.