AltruBio Announces Positive Topline Data from Phase 1 Trial of Immune Checkpoint Enhancer for the Treatment of Ulcerative Colitis

AltruBio Inc. recently announced positive topline data from its Phase 1 trial evaluating the company’s subcutaneously administered immune checkpoint enhancer (ICE), ALTB-268 in healthy volunteers.

“We are pleased to share positive topline data from our Phase 1 trial evaluating our subcutaneous ICE, ALTB-268, in healthy volunteers that will inform our planned Phase 2 clinical trials in ulcerative colitis,” said Jesse Hall, MD, Chief Medical Officer of AltruBio. “ALTB-268 demonstrated clear signs of biological activity, consistent with its mechanism of action and insights gained from our first ICE molecule, ALTB-168. Furthermore, ALTB-268 has a favorable safety profile and was well tolerated, with no serious adverse events reported. We are excited about the potential of ALTB-268 to offer a new treatment option for immunological diseases, and we remain committed to addressing the pressing medical needs of patients with autoimmune and inflammatory diseases.”

Judy Chou, PhD, President and Chief Executive Officer of AltruBio, added “The completion of this Phase 1 trial marks a significant milestone for ALTB-268 and met all development goals for advancement to Phase 2 trials. Many therapies for autoimmune disease broadly suppress the body’s immune response. We are encouraged by the favorable safety and tolerability of our novel approach that naturally restores immune balance instead. We look forward to starting exploratory biomarker clinical studies of our potent subcutaneous ICE in patients with biologics-refractory ulcerative colitis this year and beginning the Phase 2 study in 1H2024, moving us closer to providing a potentially more patient-friendly, durable and effective treatment option for those in need.”

The Phase 1 trial in healthy volunteers is a randomized, double-blind study with single and multiple ascending dose cohorts evaluating the safety, tolerability, pharmacokinetic/pharmacodynamic and immunogenicity of ALTB-268. Positive topline data strongly support the progression of ALTB-268 into Phase 2 clinical development, with ulcerative colitis identified as the primary indication for further investigation and potential treatment application in additional indications.

ALTB-268 is a tetravalent PSGL-1 agonist antibody that acts as an immune checkpoint enhancer (ICE) to preferentially downregulate chronically activated T-cells by inhibiting the T-cell effector function, promoting T-cell exhaustion and apoptosis. ALTB-268 helps to restore the immune system to a state of balance without systemic suppression, and by treating immune diseases at their source. Its unique mechanism of action is the same as the bivalent intravenously administered ICE, ALTB-168, which has previously demonstrated promising Phase 2 results in ulcerative colitis, psoriasis, psoriatic arthritis, and SR/TR-aGVHD including improved patient outcomes and clinically meaningful efficacy. ALTB-268 is formulated for subcutaneous dosage and exhibits increased potency for patient-friendly administration. A Phase 1 study evaluating the safety and tolerability of ALTB-268 in healthy volunteers showed no serious adverse events across all cohorts. An exploratory biomarker clinical study for ALTB-268 in biologics-refractory ulcerative colitis patients is anticipated to begin in Q4 2023 and a Phase 2 study in ulcerative colitis is planned to be initiated in 1H 2024. Based on the relevance of T-cell modulation in many immunological diseases, ALTB-268 has broad expansion potential in different indications and hence has significant promise as a “pipeline-in-a-product.”

AltruBio is a clinical-stage biotechnology company that specializes in developing novel therapies leveraging immune checkpoint agonism to enhance the function of natural pathways to downregulate an overactivated immune system. It is believed the mechanism of our immune checkpoint enhancers (ICEs) may hold the key to addressing the pressing medical needs of patients with autoimmune and inflammatory disorders. The company’s research team was the first to discover the novel role PSGL-1 plays as an important immune checkpoint regulator and leveraged its ability to downregulate chronic effector T-cell function and promote apoptosis and/or cell exhaustion. Robust clinical data validates proof of mechanism of our ICE therapy, ALTB-168, through enhancement of PSGL-1 function. ALTB-168 preferentially downregulates chronically activated late-stage T-cells in several diseases including ulcerative colitis, steroid refractory acute graft-versus-host disease (SR-aGVHD), psoriatic arthritis, and psoriasis, and was shown to be well tolerated with durable responses. Leveraging the same binding domain and novel mechanism demonstrated for ALTB-168, the company is advancing a more potent tetravalent ICE, ALTB-268, making it suitable for subcutaneous and patient-friendly administration. ​Led by an expert team with successful track records in drug development and commercialization in immunological diseases, AltruBio’s mission is to bring safer, more effective and durable biologic treatments to improve the lives of patients.