MAIA Biotechnology Announces First Patient Dosed in THIO-104 Phase 3 Pivotal Trial Evaluating Ateganosine as Third-Line Treatment for Advanced Non-Small Cell Lung Cancer

Rhea-AI Summary

MAIA (NYSE:MAIA) announced the first patient dosing in the THIO-104 Phase 3 pivotal trial of ateganosine given in sequence with a checkpoint inhibitor (CPI) as a third-line treatment for advanced non-small cell lung cancer (NSCLC).

The multicenter, open-label trial will randomize up to 300 patients 1:1 to ateganosine+CPI versus investigator’s choice chemotherapy, with overall survival as the primary endpoint. MAIA has regulatory approval to screen in Taiwan, Turkey, select EMA countries, and Georgia; screening and enrollment are underway.

Supporting data cited: prior THIO-101 observed PFS 5.6 months versus ~2.5 months standard of care, one patient reached 30 months survival, and the FDA has granted Fast Track designation for ateganosine in NSCLC.

Positive

• First patient dosed in the Phase 3 THIO-104 pivotal trial
• Randomized 1:1 design of up to 300 patients with overall survival endpoint
• Regulatory approval to screen in Taiwan, Turkey, select EMA countries, and Georgia
• THIO-101 showed PFS 5.6 months versus 2.5 months standard of care
• FDA granted Fast Track designation for ateganosine in NSCLC

Negative

• None.

Key Figures

Planned enrollment up to 300 patients THIO-104 Phase 3 pivotal NSCLC trial

Median overall survival 17.8 months Phase 2 THIO-101 trial, third-line NSCLC

Chemotherapy survival 6 months Typical survival with standard chemotherapy

Progression-free survival 5.6 months Observed PFS in THIO-101 as of Sept 17, 2025

Standard of care PFS 2.5 months Standard third-line NSCLC progression-free survival

Longest survival case 30 months (912 days) Single THIO-101 patient survival duration

Market Reality Check

$1.38 Last Close

Volume Volume 1,958,664 is 3.1x the 20-day average of 630,824 shares before this news. high

Technical Price at $1.38 was trading below the 200-day MA of $1.60 and about midway between the $0.87 52-week low and $2.74 high.

Peers on Argus 2 Up 1 Down

Within biotech peers, moves were mixed: BTAI up 2.34%, while CUE, PDSB, ARTV and QNTM were down between about 1.92% and 6.42%. Momentum data also showed CUE and PDSB up around 6–7% and CAMP down about 6.48%, suggesting stock-specific factors rather than a broad sector swing.

Historical Context

Date	Event	Sentiment	Move	Catalyst
Dec 01	Insider buying, clinical	Positive	+1.7%	CEO and directors bought shares and reiterated THIO‑101 efficacy and survival data.
Nov 21	Clinical program update	Positive	+4.7%	SITC 2025 update on enrollment, Phase 3 screening, and Fast Track designation.
Nov 20	Conference presentation	Positive	-5.3%	CEO presented strong response rates and Fast Track path; shares fell despite positive data.
Oct 27	Trial in progress poster	Positive	+4.9%	AACR‑NCI‑EORTC poster with early Part C enrollment and reassuring safety profile.
Oct 23	Clinical survival data	Positive	+7.3%	ESMO update highlighting 30‑month survival case in THIO‑101 Phase 2 trial.

Pattern Detected

Recent news on ateganosine and insider buying has usually seen positive price alignment, with only one notable divergence on otherwise positive clinical messaging.

Recent Company History

Over the last few months, MAIA has repeatedly highlighted progress for ateganosine in advanced NSCLC. News on Dec 1 detailed CEO and director share purchases and reiterated Phase 2 THIO‑101 data, with a modest positive move. November releases emphasized momentum of the ateganosine program, including Fast Track status and 30‑month survival data, with generally positive reactions. An October conference update on trial enrollment and safety also aligned positively. Today’s Phase 3 first‑patient dosing update extends this trajectory from Phase 2 expansion toward a pivotal registration‑oriented study.

Market Pulse Summary

The stock is up +9.1% following this news. A strong positive reaction aligns with MAIA’s history of sizable moves on clinical milestones, where prior trial updates around ateganosine produced average 1-day shifts near 7.46%. The transition from promising Phase 2 data to first-patient dosing in a Phase 3 pivotal study reinforces a clear development trajectory. However, past instances of divergence on good news and the company’s pre-news position below its 200-day MA underscore that enthusiasm could moderate as traders reassess risk and timelines.

Key Terms

checkpoint inhibitor medical

"ateganosine administered in sequence with a checkpoint inhibitor (CPI) as a third-line treatment"

A checkpoint inhibitor is a type of medicine that helps the immune system spot and attack cancer by blocking proteins that act like brakes on immune cells. For investors, these drugs matter because clinical trial results, regulatory approvals, safety profiles and market demand can quickly change a developer’s revenue and valuation; think of them as releasing the brakes on the immune system—potentially high reward but with safety and trial-risk consequences.

non-small cell lung cancer medical

"third-line treatment for advanced non-small cell lung cancer (NSCLC)"

A broad category of lung tumors that grow from the cells lining the airways and make up the majority of lung cancer cases; it includes several subtypes that behave and respond to treatment differently, like different models of the same car family. It matters to investors because its large patient population and variety of treatment options — surgery, traditional chemo, targeted drugs and immunotherapies — create major markets where clinical trial results, drug approvals or changing treatment guidelines can quickly affect a company’s revenue and stock value.

overall survival medical

"designed to assess overall survival for ateganosine sequenced with a CPI"

Overall survival is the average or median length of time patients remain alive after starting a treatment or entering a clinical study, measured regardless of cause of death. Investors care because it is a clear, hard measure of a therapy’s real-world benefit — like timing how long a new battery actually runs — and strong improvements in overall survival can drive regulatory approval, market adoption and revenue potential.

progression free survival medical

"observed progression free survival (PFS) in THIO-101 was 5.6 months"

Progression free survival is the length of time during and after a treatment when a disease, such as cancer, does not get worse or spread. It is an important measure because longer periods of stability can indicate that a treatment is effectively controlling the condition. For investors, it provides insight into the potential durability and success of a therapy or medication.

fast track designation regulatory

"The U.S. Food and Drug Administration (FDA) has granted Fast Track designation"

A "fast track designation" is a process that speeds up the review and approval of a product or project, allowing it to reach the market or be completed more quickly than usual. For investors, it can signal that a product may become available sooner, potentially leading to earlier revenue or benefits, and indicating a priority status that might influence company performance and market opportunities.

AI-generated analysis. Not financial advice.

Key milestone achieved as Company advances clinical program to full approval trial of ateganosine sequenced with a checkpoint inhibitor in comparison to chemotherapy

CHICAGO, Dec. 11, 2025 (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 the first patient has been dosed in the Company’s THIO-104 Phase 3 pivotal trial evaluating the efficacy of ateganosine administered in sequence with a checkpoint inhibitor (CPI) as a third-line treatment for advanced non-small cell lung cancer (NSCLC).

The multicenter, open-label trial of patients who are resistant to CPI and chemotherapy treatments, is 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. Screening and enrollment are now underway.

“Our strategy to bring our telomere-targeting treatment to market is proceeding according to plan as we advance our ateganosine program to a Phase 3 trial. This larger trial will provide us a robust dataset to support our case for commercial approval by the U.S. FDA,” said Vlad Vitoc, M.D., CEO of MAIA. “We have many sites in several countries already screening patients, and with our first patient dosed, we have achieved a key milestone along our path to potential FDA commercial approval. We expect to see Phase 3 results consistent with Phase 2 trial data showing median survival of 17.8 months compared to approximately six months of survival from chemotherapy. We are confident that ateganosine could become the new treatment standard for patients suffering from this devastating disease.”

Ateganosine sequenced with a CPI has shown exceptional efficacy in third-line NSCLC patients. As of September 17, 2025, the observed progression free survival (PFS) in THIO-101 was 5.6 months, more than double the standard of care PFS of 2.5 months. One patient that began therapy in March 2023 has shown survival of 30 months, or 912 days. 

The U.S. Food and Drug Administration (FDA) has granted Fast Track designation for ateganosine for the treatment of NSCLC.

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-104 Phase 3 Clinical Trial

THIO-104 is a multicenter, open-label, randomized Phase 3 clinical trial, designed to evaluate ateganosine’s telomere-targeting anti-tumor activity when followed by PD-(L)1 inhibition in patients with advanced third-line NSCLC who previously did not respond or developed resistance to treatment regimens containing checkpoint inhibitor and/or chemotherapy and have progressed. The trial has two primary objectives: (1) to assess the clinical efficacy of ateganosine compared to investigator’s choice of chemotherapy, using median Overall Survival (OS) as the primary clinical endpoint (2) to evaluate the safety and tolerability of ateganosine in sequential combination with a checkpoint inhibitor. For more information on this Phase 3 trial, please visit ClinicalTrials.gov using the identifier NCT06908304.

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 www.maiabiotech.com.

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

FAQ

What did MAIA announce on December 11, 2025 about THIO-104 (MAIA)?

MAIA announced the first patient dosing in the THIO-104 Phase 3 trial of ateganosine plus a CPI as third-line treatment for advanced NSCLC.

How many patients will be enrolled in MAIA's THIO-104 Phase 3 trial (MAIA)?

The trial will randomize up to 300 patients in a 1:1 allocation between ateganosine+CPI and investigator’s choice chemotherapy.

Where is MAIA allowed to screen patients for the THIO-104 trial (MAIA)?

MAIA has regulatory approval to screen in Taiwan, Turkey, select EMA countries, and Georgia.

What prior clinical results did MAIA cite to support THIO-104 (MAIA)?

MAIA cited THIO-101 results showing observed PFS 5.6 months versus approximately 2.5 months standard of care, and one patient with 30 months survival.

Does ateganosine have any expedited regulatory status (MAIA)?

Yes, the U.S. FDA has granted Fast Track designation for ateganosine for the treatment of NSCLC.