AltruBio Reports Positive Data from Phase 2a Trial of ALTB-268

SAN FRANCISCO, Oct. 20, 2026 /CourierPR/ -- AltruBio Inc., a clinical-stage biotech company, has announced positive data from its open-label Phase 2a ASCEND UC2a trial evaluating ALTB-268, its first-in-class subcutaneous (SC) PSGL-1 immune modulator, in patients with moderately to severely active ulcerative colitis (UC) who had failed prior advanced therapies. The data were presented at the United European Gastroenterology (UEG) Week 2026 conference by David T. Rubin, MD, AGAF, MACG, FACP, Joseph B. Kirsner Professor of Medicine, University of Chicago.

The ASCEND UC2a (NCT06109441) study, which enrolled participants sequentially in two cohorts, showed dose-related clinical activity. In higher-dose Cohort 2, 23.1% (3/13) of patients achieved clinical remission by Week 12, compared to 11.4% (4/35) in lower-dose Cohort 1. Additionally, 38.9% (7/18) of participants with a Day 29 trough concentration at or above the target level achieved clinical remission at Week 12, when data were pooled from both cohorts.

The study also demonstrated endoscopic improvement, with 17.1% (6/35) of patients in Cohort 1 and 23.1% (3/13) in Cohort 2 achieving improvement. Clinical response was 34.3% (12/35) in Cohort 1 and 53.8% (7/13) in Cohort 2. Patient-reported quality of life, measured by the Inflammatory Bowel Disease Questionnaire (IBDQ), improved in 51.4% (18/35) of patients in Cohort 1 and 53.8% (7/13) in Cohort 2.

The company plans to initiate a global Phase 2b placebo-controlled trial, ASCEND UC2b, in 2027. This study will evaluate two active dose levels of ALTB-268 and assess both induction of clinical remission and durability of response during maintenance. The ASCEND UC2a trial, which was open-label and dose-exploration, evaluated the efficacy, safety, tolerability, and pharmacokinetics of ALTB-268 in participants with moderately to severely active UC who had an inadequate response to at least one prior advanced therapy.

ALTB-268 is a subcutaneously administered, tetravalent agonist antibody targeting PSGL-1, a key immune modulator. It preferentially downregulates chronically activated, late-stage T effector cells, leading to their exhaustion and/or ultimate apoptosis. Its unique mechanism of action to restore immune balance has been clinically validated by AltruBio’s first-generation asset, which previously demonstrated promising Phase 2 results in ulcerative colitis, psoriasis, psoriatic arthritis, and steroid-refractory/treatment-refractory acute graft-versus-host disease (SR/TR-aGvHD).

The data from the ASCEND UC2a trial indicate that ALTB-268 was well tolerated, with a similar overall proportion of treatment-emergent adverse events across both cohorts despite a two-fold difference in dose. The most common TEAE was injection site reaction, which decreased with repeat administration and was not observed in either cohort by the end of the induction period. One serious adverse event was reported, in Cohort 1, and there were no deaths.

The findings from the ASCEND UC2a trial support the potential of ALTB-268 to reshape the treatment landscape for patients with UC. The upcoming Phase 2b study will further demonstrate the clinical profile of ALTB-268 and its unique role in the evolving UC treatment paradigm.