Altrubio, Inc.

ALTB-268 demonstrated its anti-inflammatory effect in an acute colitis hPSGL-1 mouse model. The data confirmed that ALTB-268 acts as an immune checkpoint enhancer, downregulating T cell effector function and restoring immune system balance. SAN FRANCISCO, Oct. 28, 2024 (GLOBE NEWSWIRE) -- AltruBio Inc. (“AltruBio” or “the Company”), a clinical-stage biotech company developing novel immune checkpoint enhancers to address the unmet need in immunological and inflammatory diseases, with a current focus on ulcerative colitis (UC), today announced new in-vivo proof-of-concept data for their lead candidate ALTB-268 at the 9th Federation of Immunological Societies of Asia-Oceania (FIMSA) 2024 Congress, taking place in Taipei from October 23-27, 2024. The data demonstrates ALTB-268’s in vivo efficacy and confirms its mechanism of action as an immune checkpoint enhancer in a non-clinical disease model, further supporting its clinical development for ulcerative colitis (UC). "We are pleased to continue building evidence of ALTB-268’s potential to treat T-cell-mediated inflammatory diseases, through its unique mechanism of action as an immune checkpoint enhancer targeting the PSGL-1 pathway," said Dr. Judy Chou, President and Chief Executive Officer of AltruBio. "The anti-inflammatory effects observed in a mouse model of acute colitis further support ALTB-268’s clinical advancement for UC. We look forward to sharing data from the ongoing Phase 2a trial in UC in the second half of 2025 and demonstrating how its distinct mechanism of action may translate into clinical potential. With its novel immune checkpoint enhancement and subcutaneous administration, ALTB-268 could transform the treatment landscape for UC and other immunological and inflammatory diseases with unmet needs." Poster Session: 2Title: ALTB-268, A PSGL-1 Agonistic Antibody, Demonstrates Anti-Inflammatory Effect in an Acute Colitis Model Established in Human PSGL-1 Knock-in Mice.Presenter: Evelyn Chiang, Ph.D.Date and Time: Saturday October 26, 2024, 10:20 a.m. TST-10:50 a.m. TST.Poster Number: SAT-4-013 Key data highlights include: Treatment with ALTB-268 inhibited human T cell activation in-vitro and in-vivo, confirming its mechanism of action.In a dextran sodium sulphate (DSS)-induced colitis hPSGL-1 mice model, ALTB-268 ameliorated disease severity; it reduced the disease activity index (DAI) score, the colon weight/length ratio and histological damage of colitis, in addition to reducing inflammatory cytokines and leukocyte infiltration in the colon.An intact leukocyte migration observed in hPSGL-1 KI mice suggests that these newly generated mice provide a valuable animal model for MOA and translational studies for anti-hPSGL-1 monoclonal antibodies and Fc-fusion proteins. About ALTB-268ALTB-268 is a subcutaneously administered, tetravalent agonist antibody targeting PSGL-1, a key immune checkpoint regulator. It acts as an immune checkpoint enhancer (ICE), preferentially downregulating chronically activated late-stage T effector cells, leading to their exhaustion and/or apoptosis. Its unique mechanism of action is the same as AltruBio’s bivalent, intravenously administered ICE, ALTB-168, 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), including improved patient outcomes and clinically meaningful efficacy. A Phase 2a exploratory biomarker study for ALTB-268 in biologics-refractory ulcerative colitis patients is currently enrolling patients. A randomized global Phase 2b study open to both advanced therapy experienced and naïve patients is planned to be initiated in first half of 2025. Both studies have the same primary and secondary end points in clinical remission and endoscope improvement. Given that T-cell modulation is key in the management of multiple immunological diseases, ALTB-268 has broad indication expansion potential, making it a promising “pipeline-in-a-product.” About AltruBio Inc.AltruBio is a clinical-stage biotechnology company developing novel therapies leveraging immune checkpoint agonism to address unmet medical needs in immunological and inflammatory diseases. The Company’s lead candidate, ALTB-268, acts as an immune checkpoint enhancer (ICE), designed to activate natural pathways that downregulate a chronically overactivated immune system to restore balance. ALTB-268 operates through a unique mechanism of action, targeting PSGL-1, a key immune checkpoint regulator. It preferentially targets and downregulates chronically activated late-stage effector T cells, leading to their exhaustion and/or apoptosis. Currently being evaluated in a Phase 2 trial in ulcerative colitis, ALTB-268 holds the potential to be a pipeline in a product to address a range of inflammatory diseases, which AltruBio plans to explore in upcoming Phase 2 trials. Led by an expert team with successful track records in drug development and commercialization in immunology, AltruBio is dedicated to delivering safer, more effective, and durable biologic treatments to improve the lives of patients. Note on Forward-Looking StatementsStatements made in this news release that are not historical facts are forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Words such as expects, believes, intends, and similar expressions are intended to identify forward-looking statements. Actual results may differ materially from those projected in any forward-looking statement. Specifically, there are a number of important factors that could cause actual results to differ materially from those anticipated, such as the Company's ability to raise additional capital, and risks related to the Company's ability to initiate, and enroll patients in, planned clinical trials. You should not place undue reliance on any forward-looking statements. The Company assumes no obligation to update any forward-looking statements as a result of new information, future events or developments, except as required by law. Contacts AltruBio Inc: +1-415-655-6603 info@altrubio.com Media Contact:LifeSci CommunicationsLuke Shiplolshiplo@lifescicomms.com

Financing led by BVF Partners LP, with participation from new investors RA Capital Management, Cormorant Asset Management, Soleus Capital and existing investors aMoon Fund and Blackstone Multi-Asset Investing, among other new and existing investors Funds will be used to support ongoing and planned Phase 2a and 2b clinical trials of immune checkpoint enhancer, ALTB-268, in ulcerative colitis SAN FRANCISCO, May 21, 2024 (GLOBE NEWSWIRE) -- AltruBio Inc. (“AltruBio” or “the Company”), a clinical stage biotechnology company dedicated to the development of novel therapeutics for the treatment of immunological diseases with high unmet medical needs, today announced an oversubscribed Series B financing of up to $225 million. AltruBio plans to use the proceeds of the financing to advance the clinical development of the Company’s first-in-class, novel immune checkpoint enhancer (ICE) PSGL-1 agonist antibody, ALTB-268. The funds will be used to support ongoing and planned Phase 2 clinical trials in ulcerative colitis (UC), one of many immunological disorders where the mechanism has been clinically validated. The financing was led by BVF Partners LP with participation from new investors RA Capital Management, Cormorant Asset Management, and Soleus Capital, as well as existing investors aMoon Fund and Blackstone Multi-Asset Investing, with other new and existing investors joining the syndicate. The Company’s first-in-class, novel ICE agonist antibody, ALTB-268, is currently being studied in a Phase 2a exploratory biomarker study in patients with biologic refractory UC with an anticipated readout for its primary endpoint of clinical remission per modified Mayo score in 1H 2025. The company plans to initiate a global Phase 2b randomized, placebo-controlled clinical trial with a primary endpoint of clinical remission in both advanced therapy experienced and treatment naive patients with moderately to severely active UC. This study is anticipated to read out in 2H of 2026. "We are honored to welcome this esteemed new group of investors, whose participation complements the support of our existing world-class investor group. Their collective backing not only affirms the potential of our program and company but also our mission of developing durable biologic therapies for patients suffering from autoimmune diseases,” said Dr. Judy Chou, President and Chief Executive Officer of AltruBio. “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 2a exploratory biomarker study and initiate an additional Phase 2b study, while paving the way for potential indication expansion beyond ulcerative colitis. With our experienced team in place and this significant financing, we are poised to accelerate our efforts and deliver innovative treatments to patients in need." “Treatment options remain limited in many autoimmune conditions, including moderate to severe ulcerative colitis, and novel mechanisms are sorely needed,” commented Gorjan Hrustanovic, Ph.D., Managing Director at BVF Partners LP. “We are excited to support AltruBio and their commitment to developing a potential first-in-class medicine across multiple autoimmune indications, starting with UC.” “Our investment in AltruBio represents an exciting opportunity to contribute to the dynamic and rapidly evolving landscape of the inflammatory and immunological space. The heightened interest and substantial funding in this sector underscore the urgent need for innovative solutions to address the unmet medical needs of patients. We share a collective vision with AltruBio to advance first-in-class medicines, recognizing the potential to revolutionize patient care and drive impactful change within this field," said Jake Simson, Ph.D., Partner of RA Capital Management. About ALTB-268ALTB-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 down regulation. ALTB-268 is designed to help 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 exhibited increased potency in preclinical studies and is formulated for subcutaneous dosing for patient-friendly administration. A Phase 1 study of ALTB-268 has demonstrated the safety and tolerability in healthy volunteers with no serious adverse events across all cohorts. A Phase 2a exploratory biomarker study for ALTB-268 in biologics-refractory ulcerative colitis patients is currently enrolling patients and a randomized Phase 2b study in ulcerative colitis is planned to be initiated later in 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.” About AltruBio Inc.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 the 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 down regulation. Robust clinical data validates proof of mechanism of the Company’s ICE therapy, ALTB-168, through enhancement of PSGL-1 function. ALTB-168 is designed to preferentially downregulate 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. MTS Securities, LLC acted as the exclusive placement agent in connection with the financing. Note on Forward-Looking StatementsStatements made in this news release that are not historical facts are forward-looking statements. These forward-looking statements include, but are not limited to, statements about the Series B financing, including those with respect to subsequent closings, the use of proceeds from the Series B financing, and the progress and timing of the Company’s clinical trials, including the timing and availability of data from such trials. Words such as expects, believes, plans, anticipates, intends, potential, design and similar expressions are intended to identify forward-looking statements. Actual results may differ materially from those projected in any forward-looking statement. Specifically, there are a number of important factors that could cause actual results to differ materially from those anticipated, such as the Company's ability to achieve certain milestones and complete subsequent closings of the Series B financing, raise additional capital, and risks related to the Company's ability to initiate, and enroll patients in, planned clinical trials. The forward-looking statements included in this press release represent the Company’s views as of the date hereof. These forward-looking statements should not be relied upon as representing the Company’s views as of any date subsequent to the date hereof. The Company assumes no obligation to update any forward-looking statements as a result of new information, future events or developments, except as required by law. Contacts AltruBio Inc: +1-415-655-6603 info@altrubio.com Media Contact:LifeSci CommunicationsLuke Shiplolshiplo@lifescicomms.com

Phase 2a exploratory biomarker study in ulcerative colitis underway; Phase 2b placebo controlled clinical trial in the same indication on track to launch in 2024.SAN FRANCISCO, Dec. 07, 2023 (GLOBE NEWSWIRE) -- AltruBio Inc. (“AltruBio” or “the Company”), a clinical stage biotech company dedicated to the development of novel therapeutics for the treatment of immunological diseases with high unmet medical needs, today announced the first patient enrolled for the Phase 2a clinical study of the company’s subcutaneously administered immune checkpoint enhancer (ICE), ALTB-268 in ulcerative colitis (UC). The company’s Phase 2 clinical program consists of a phase 2a open-label study in patients with biologic refractory UC and a phase 2b randomized, placebo-controlled study in patients with moderately to severely active UC. “We are excited to reach this critical milestone, as we work to bring ALTB-268 to patients with autoimmune inflammatory disorders,” said Dr. Jesse Hall, Chief Medical Officer of AltruBio. “PSGL-1 is upregulated in several autoimmune diseases including UC. This Phase 2a study aims to identify potential biomarkers of ALTB-268 treatment. The unique mechanism of action for supports a truly differentiated therapeutic approach for inflammatory bowel disease. In addition to the phase 2a study already underway in patients with biologics refractory disease, in 2024 the company aims to start a larger, global phase 2b randomized, placebo controlled study in patients with moderately to severely active UC. The phase 2b study will be open to both advanced therapy experienced and naïve patients. About ALTB-268ALTB-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 exhibits increased potency in preclinical studies and is formulated for subcutaneous dosage 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. A Phase 2 exploratory biomarker clinical study for ALTB-268 in biologics-refractory ulcerative colitis patients is anticipated to begin by end of 2023 and a randomized Phase 2 study in ulcerative colitis is planned to be initiated in 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.” About AltruBio Inc.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. Note on Forward-Looking StatementsStatements made in this news release that are not historical facts are forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Words such as expects, believes, intends, and similar expressions are intended to identify forward-looking statements. Actual results may differ materially from those projected in any forward-looking statement. Specifically, there are a number of important factors that could cause actual results to differ materially from those anticipated, such as the Company's ability to raise additional capital, and risks related to the Company's ability to initiate, and enroll patients in, planned clinical trials. You should not place undue reliance on any forward-looking statements. The Company assumes no obligation to update any forward-looking statements as a result of new information, future events or developments, except as required by law. Contacts AltruBio Inc: +1-415-655-6603 info@altrubio.com