Cemiplimab-RWLC

Additional data from MAIA’s THIO-101 expansion may further support an accelerated approval filing with the FDA Potential breakthrough therapy holds substantial commercial opportunity in a projected $70 billion global non-small cell lung cancer market by 2030 1 CHICAGO, June 10, 2026 (GLOBE NEWSWIRE) -- MAIA Biotechnology, Inc. (NYSE American: MAIA) (“MAIA”, the “Company”), a clinical-stage biopharmaceutical company focused on developing targeted immunotherapies for cancer, today announced that it has activated the second U.S. clinical site in its Phase 2 THIO-101 expansion trial at Central Alabama Research in Homewood, Alabama. The expansion part of THIO-101 evaluates MAIA’s lead investigational therapy, ateganosine, a dual-action molecule incorporating telomere targeting and immunogenicity, as a third-line (3L) treatment for non-small cell lung cancer (NSCLC) in patients who have previously failed treatment with checkpoint inhibitors (CPIs) and chemotherapy. Parts A and B of the Phase 2 THIO-101 Phase 2 trial provided key inputs for MAIA’s market strategy by identifying optimal dosing for a well-defined patient population. The THIO-101 expansion trial is ongoing in Europe and Asia with 44 active sites in 6 countries along with 2 in the U.S. The additional data from the trial’s expansion may further support an accelerated approval filing with the FDA. “Adding our second U.S. site reflects strong execution of our clinical strategy and continued momentum in the expansion of the THIO-101 trial,” said Vlad Vitoc, M.D., Founder and Chief Executive Officer of MAIA. “Broadening our site footprint enables more efficient patient enrollment as we advance the program under the FDA Fast Track designation and work toward upcoming interim data milestones.” David J. Mooney, M.D., oncology physician at Central Alabama Research and principal investigator for THIO-101 in Alabama commented, “We look forward to bringing ateganosine treatment to our cancer center. There’s a large regional patient pool across the Southeast, including underserved and rural populations, that can greatly benefit from a novel therapy in this hard-to-treat NSCLC setting with very limited treatment options.” In parallel with the Phase 2 clinical trial, MAIA is actively screening and enrolling patients in a pivotal Phase 3 clinical trial designed to assess overall survival for ateganosine sequenced with a CPI compared to investigator’s choice of chemotherapy in a 1:1 randomization of up to 300 patients. MAIA has received regulatory approval to screen patients in Taiwan, Turkey, select European Medicines Agency (EMA) countries, and Georgia. About Ateganosine Ateganosine (THIO, 6-thio-dG or 6-thio-2’-deoxyguanosine) is a first-in-class investigational telomere-targeting agent currently in clinical development to evaluate its activity in non-small cell lung cancer (NSCLC). Telomeres, along with the enzyme telomerase, play a fundamental role in the survival of cancer cells and their resistance to current therapies. The modified nucleotide 6-thio-2’-deoxyguanosine induces telomerase-dependent telomeric DNA modification, DNA damage responses, and selective cancer cell death. Ateganosine-damaged telomeric fragments accumulate in cytosolic micronuclei and activates both innate (cGAS/STING) and adaptive (T-cell) immune responses. The sequential treatment of ateganosine followed by PD-(L)1 inhibitors resulted in profound and persistent tumor regression in advanced, in vivo cancer models by induction of cancer type–specific immune memory. Ateganosine is presently developed as a second or later line of treatment for NSCLC for patients that have progressed beyond the standard-of-care regimen of existing checkpoint inhibitors. About THIO-101 Phase 2 Clinical Trial THIO-101 is a multicenter, open-label, dose finding Phase 2 clinical trial. It is the first trial designed to evaluate ateganosine’s anti-tumor activity when followed by PD-(L)1 inhibition. The trial is testing the hypothesis that low doses of ateganosine administered prior to cemiplimab (Libtayo ® ) will enhance and prolong immune response in patients with advanced NSCLC who previously did not respond or developed resistance and progressed after first-line treatment regimen containing another checkpoint inhibitor. The trial design has two primary objectives: (1) to evaluate the safety and tolerability of ateganosine administered as an anticancer compound and a priming immune activator (2) to assess the clinical efficacy of ateganosine using Overall Response Rate (ORR) as the primary clinical endpoint. The expansion of the study will assess overall response rates (ORR) in advanced NSCLC patients receiving third line (3L) therapy who were resistant to previous checkpoint inhibitor treatments (CPI) and chemotherapy. Treatment with ateganosine followed by cemiplimab (Libtayo ® ) has shown an acceptable safety pro date in a heavily pre-treated population. For more information on this Phase II trial, please visit ClinicalTrials.gov using the identifier NCT05208944. About MAIA Biotechnology, Inc. MAIA is a targeted therapy, immuno-oncology company focused on the development and commercialization of potential first-in-class drugs with novel mechanisms of action that are intended to meaningfully improve and extend the lives of people with cancer. Our lead program is ateganosine (THIO), a potential first-in-class cancer telomere targeting agent in clinical development for the treatment of NSCLC patients with telomerase-positive cancer cells. For more information, please visit . Forward Looking Statements MAIA cautions that all statements, other than statements of historical facts contained in this press release, are forward-looking statements. Forward-looking statements are subject to known and unknown risks, uncertainties, and other factors that may cause our or our industry’s actual results, levels or activity, performance or achievements to be materially different from those anticipated by such statements. The use of words such as “may,” “might,” “will,” “should,” “could,” “expect,” “plan,” “anticipate,” “believe,” “estimate,” “project,” “intend,” “future,” “potential,” or “continue,” and other similar expressions are intended to identify forward looking statements. However, the absence of these words does not mean that statements are not forward-looking. For example, all statements we make regarding (i) the initiation, timing, cost, progress and results of our preclinical and clinical studies and our research and development programs, (ii) our ability to advance product candidates into, and successfully complete, clinical studies, (iii) the timing or likelihood of regulatory filings and approvals, (iv) our ability to develop, manufacture and commercialize our product candidates and to improve the manufacturing process, (v) the rate and degree of market acceptance of our product candidates, (vi) the size and growth potential of the markets for our product candidates and our ability to serve those markets, and (vii) our expectations regarding our ability to obtain and maintain intellectual property protection for our product candidates, are forward looking. All forward-looking statements are based on current estimates, assumptions and expectations by our management that, although we believe to be reasonable, are inherently uncertain. Any forward-looking statement expressing an expectation or belief as to future events is expressed in good faith and believed to be reasonable at the time such forward-looking statement is made. However, these statements are not guarantees of future events and are subject to risks and uncertainties and other factors beyond our control that may cause actual results to differ materially from those expressed in any forward-looking statement. Any forward-looking statement speaks only as of the date on which it was made. We undertake no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by law. In this release, unless the context requires otherwise, “MAIA,” “Company,” “we,” “our,” and “us” refers to MAIA Biotechnology, Inc. and its subsidiaries. Investor Relations Contact +1 (872) 270-3518 ir@maiabiotech.com 1 Research and Markets, Non-Small Cell Lung Cancer (NSCLC) Global Market Trends and Regional Growth Insights 2026-2030, March 2026

Data from Phase 1b EMITT-1 trial presented in oral session at ASCO 2026 Annual Meeting First-in-class oral ERAP1 inhibitor demonstrates objective response rates (ORR) of 13–36% across patients with secondary anti-PD-1 resistance or microsatellite stable colorectal cancer without liver metastases in combination with cemiplimab (anti-PD-1) Long-lasting responses observed in patients, with multiple patients remaining progression-free for over 6 months across multiple tumor types Therapy was well tolerated with no safety signals and the trial is ongoing OXFORD, United Kingdom, June 02, 2026 (GLOBE NEWSWIRE) -- Greywolf Therapeutics, a clinical-stage biotech company advancing novel antigen modulation treatments for cancer and autoimmune diseases, today reports clinical and translational results from six completed Phase 1b expansion cohorts of the EMITT-1 trial ( NCT06923761 ) evaluating GRWD5769, a first-in-class oral ERAP1 inhibitor, in combination with cemiplimab in patients with secondary anti-PD-1 resistance or microsatellite stable colorectal cancer without liver metastases (MSS-CRC NLM). Data were presented in an oral session at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting by Professor Fiona Thistlethwaite, Consultant Medical Oncologist at The Christie NHS Foundation Trust and Medical Director of the National Institute for Health and Care Research (NIHR) Manchester Clinical Research Facility at The Christie, and Principal Investigator of the EMITT-1 trial. Professor Fiona Thistlethwaite, Consultant Medical Oncologist at The Christie NHS Foundation Trust and Medical Director of the National Institute for Health and Care Research (NIHR) Manchester Clinical Research Facility at The Christie said: “What excites me about this trial is the combination of what we’re seeing - strong signals of efficacy across six tumor types that have shown great resistance to immunotherapy, with very few side effects. That's unusual at such an early stage.” Highlights from the Phase 1b data Objective Response Rates (ORR) of 13–36% across all six cohorts in patients with a median of 2 prior lines of therapy and documented secondary anti-PD-1 resistance (except MSS-CRC (NLM) where this therapy is not effective) Durable Clinical Benefit of 18–55% across all cohorts (DCB — defined as complete response, partial response, or stable disease lasting ≥6 months) and Progression Free Survival duration of 33 wks in NSCLC, 16 wks in HCC and 33 wks in MSS-CRC (NLM) (with 8.8 months median follow-up and still maturing). These data are very encouraging in a setting where durable benefit is exceptionally rare. GRWD5769 is well tolerated in cemiplimab combination, with no safety signals and most adverse events being Grade 1 Evaluable* (n) Partial response(s) Overall response rate (%) Durable clinical benefit (%) Progression-free survival (wks) Urothelial carcinoma 14 5 36 36 8 Non-small cell lung cancer 14 3 21 55 33 Hepatocellular carcinoma (liver cancer) 14 2 14 32 16 Microsatellite stable colorectal cancer (no liver metastases) 12 2 17 51 33 Cervical 14 2 14 18 9 Head and neck squamous cell carcinoma 8 1 13 38 14 Tom Lillie, Chief Medical Officer of Greywolf Therapeutics, said: “Seeing the combination of strong durable clinical benefit rates and sustained PFS in a population that had already failed anti-PD-1 therapy, and in MSS-CRC where it isn’t licensed, is a clinically meaningful signal. Critically, we're seeing this alongside a tolerability pro enables patients to remain on treatment for extended periods, providing excellent potential for GRWD5769 to be used in other combination therapies.” Peter Joyce, CEO and Co-founder of Greywolf Therapeutics, said: “EMITT-1 has validated a mechanism that the field has long recognized as scientifically compelling but clinically unproven. We are now advancing into Stage 2 cohort expansions to inform a randomized Phase 2 study, and we believe this data positions GRWD5769 as a genuinely differentiated approach to two of the largest unmet needs in oncology — T cell exhaustion and tumor visibility to the immune system.” About GRWD5769 GRWD5769 is a first-in-class oral small molecule inhibitor of Endoplasmic Reticulum Aminopeptidase 1 (ERAP1), an enzyme that regulates tumor antigen presentation on MHC-I. By inhibiting ERAP1 on a cyclical Q3W on/off schedule, GRWD5769 aims to generate alternating antigenic repertoires to broaden T cell responses and prevent T cell exhaustion driven by chronic antigen exposure. The drug is administered as an oral capsule in combination with cemiplimab, an approved anti-PD-1 therapy. About the EMITT-1 trial EMITT-1 ( NCT06923761 ) is a global Phase 1/2 study evaluating GRWD5769 in combination with cemiplimab across multiple solid tumor types. The Phase 1b expansion enrolled patients across six cohorts: non-small cell lung cancer (NSCLC), urothelial carcinoma (UC), hepatocellular carcinoma (HCC), MSS-CRC (without liver metastases), squamous cell carcinoma of the head and neck (SCCHN), and cervical cancer. All patients had secondary resistance to prior anti-PD-1 therapy, except for the MSS-CRC NLM cohort. The trial is ongoing across 28 centers in Australia, France, Spain, and the United Kingdom. About Greywolf Therapeutics Greywolf Therapeutics is a clinical-stage biotech company advancing novel antigen modulation treatments for cancer and autoimmune diseases. The company’s first-in-class small molecules are developed to control T cell activation by modulating antigen presentation, altering how cells appear to the immune system so it can recognize and target them correctly. Greywolf is headquartered in Oxford, UK. More information: Website | LinkedIn Media enquiries Patrick White, Head of Communications +44 (0)1235 644 970 patrick.white@gwt.bio