MAIA Biotechnology Doses First U.S. Patient in Ongoing Phase 2 Non-Small Cell Lung Cancer Clinical Trial

On September 16, 2026 MAIA Biotechnology, Inc. (NYSE American: MAIA) ("MAIA", the "Company"), a clinical-stage biopharmaceutical company focused on developing targeted immunotherapies for cancer, reported that the first U.S. patient has been dosed in its Phase 2 THIO-101 trial expansion evaluating its telomere-targeting lead candidate, ateganosine, in third-line non-small cell lung cancer (NSCLC). The U.S. Phase 2 expansion is funded by a $2.3 million grant from the National Institutes of Health (NIH) to support third-line treatment evaluation and MAIA has activated 3 sites in the U.S.

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MAIA holds FDA Fast Track designation for ateganosine, a dual mechanism therapy designed to break down telomere structure and function in cancer cells while inducing immune activation. Prior data from THIO-101 Parts A and B show overall survival (OS) beyond 24 months in eight patients receiving ateganosine sequenced with a checkpoint inhibitor.

"We have worked diligently to advance ateganosine into the U.S. market, and dosing the first patient in the United States represents a major milestone for our ongoing Phase 2 clinical trial," said Vlad Vitoc, M.D., Founder and Chief Executive Officer of MAIA. "Our collaborations with some of the nation’s top institutions and foremost oncologists further strengthen the trial as we evaluate ateganosine for patients in advanced stages of this exceedingly hard-to-treat disease. We believe the data generated through the THIO-101 program may also support a potential pathway toward FDA accelerated approval. With patients now enrolled across four continents, the study has evolved into a truly global effort focused on addressing a critical unmet need in cancer care."

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 profile to date in a heavily pre-treated population. For more information on this Phase II trial, please visit ClinicalTrials.gov using the identifier NCT05208944.

(Press release, MAIA Biotechnology, SEP 16, 2026, View Source [SID1234670911])