MAIA Biotechnology Details 30-Month Patient Survival in Ongoing Phase 2 Clinical Trial in Non-Small Cell Lung Cancer

Rhea-AI Summary

MAIA Biotechnology (NYSE: MAIA) reported clinical highlights from ESMO Congress 2025 describing extended survival in non-small cell lung cancer (NSCLC) patients treated with ateganosine (THIO).

Key point: as of Sept 17, 2025 one THIO-101 patient who began therapy in March 2023 showed 30 months (912 days) survival; that patient completed treatment after the protocol maximum of two years. MAIA presented two e-posters on Oct 19, 2025 covering the ongoing Phase 2 (THIO-101) and Phase 3 (THIO-104) trials in ICI-resistant advanced NSCLC; posters are available at maiabiotech.com/publications.

Positive

• Single-patient survival: 912 days (30 months) reported as of Sept 17, 2025
• Two trials active: Phase 2 THIO-101 and Phase 3 THIO-104 presented at ESMO 2025
• Public disclosure: ESMO e-posters posted on company publications page

Negative

• Data limited: 30-month result is a single reported patient, not a cohort readout
• Ongoing studies: THIO-101 and THIO-104 are still in progress with no randomized efficacy claim
• Treatment cap: patient stopped at protocol maximum of 2 years, limiting continuous-treatment evidence

Insights

Clinical Oncology Analyst

Single-patient 30-month survival is notable but anecdotal; meaningful impact awaits controlled trial data.

The report highlights a single THIO-101 patient who started therapy in March 2023 and, as of September 17, 2025, reached 30 months (912 days) of survival after receiving ateganosine every three weeks until the protocol maximum two-year treatment duration. This is an objectively long observation for a heavily pretreated, ICI‑resistant non‑small cell lung cancer patient and therefore signals potential clinical activity of the agent in at least one individual case.

Credible limitations exist: the data point describes one patient only, with no contemporaneous control, no aggregate survival statistics, and no disclosed primary endpoints or statistical context from the ongoing Phase 2 or Phase 3 trials. These gaps prevent reliable inference about population‑level benefit, effect size, or safety profile; the announcement does not provide median overall survival, response rates, progression‑free survival, or number of evaluable patients.

Watch for prespecified, peer‑reviewed trial readouts that report primary endpoints and population summaries from THIO-101 and THIO-104, plus details on censoring, duration of follow‑up, and safety; the company presented e-posters at ESMO beginning October 19, 2025 and posted materials on its website. Over the next 6–18 months, the key items to monitor are formal interim analyses, the Phase 3 primary endpoint readout, and full Kaplan–Meier curves showing median survival and confidence intervals.

• Outstanding measure of efficacy relative to high-risk cancers with limited treatment options
  

CHICAGO, Oct. 23, 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 highlights from a recent presentation at the European Society for Medical Oncology (ESMO) Congress 2025 held in Berlin, Germany. Starting October 19, 2025, MAIA showcased two e-posters at ESMO detailing its ongoing Phase 2 and Phase 3 clinical trials of ateganosine in non-small cell lung cancer (NSCLC).

“The posters showcased at ESMO 2025 featured exceptional extended survival in third-line NSCLC patients. In addition, as of September 17, 2025, a patient that began therapy in March 2023 has shown survival of 30 months, or 912 days, an outstanding measure relative to many of the high-risk cancers,” said MAIA CEO Vlad Vitoc, M.D. “Very few options exist for patients who are refractory or resistant to immune checkpoint inhibitors (ICI). We believe that a survival of over two years is a clear signal of ateganosine’s role in effectively targeting and eliminating NSCLC tumor cells.”

The THIO-101 patient with 30-month survival received therapy every three weeks, and concluded treatment upon reaching the maximum treatment duration of 2 years based on protocol requirements.

MAIA’s newest posters featured at ESMO 205 are now available on MAIA’s website at maiabiotech.com/publications.

• Presentation 1: A Phase 2 Study of Ateganosine (THIO; 6-thio-2'-deoxyguanosine) in Combination with Immune Checkpoint Inhibitor (ICI) in Patients with Advanced Non-Small Cell Lung Cancer (NSCLC) Resistant to Prior ICI and Chemotherapy: THIO-101 Trial in Progress
  
  
• Presentation 2: A Phase 3 Study of Ateganosine (THIO) Sequenced with Immune Checkpoint Inhibitor (ICI) versus Standard of Care Chemotherapy in ICI-Resistant Advanced NSCLC: THIO-104 Trial in Progress
  
  

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.

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 survival outcome did MAIA (MAIA) report for ateganosine at ESMO 2025?

MAIA reported one THIO-101 patient reached 30 months (912 days) survival as of Sept 17, 2025.

When and where did MAIA present THIO-101 and THIO-104 trial updates?

MAIA showcased two e-posters at ESMO Congress 2025 in Berlin, beginning Oct 19, 2025.

Which MAIA trials were detailed at ESMO 2025 for NSCLC?

Presentation of Phase 2 THIO-101 (ateganosine + ICI) and Phase 3 THIO-104 (ateganosine sequenced with ICI).

Where can investors read the MAIA ESMO 2025 e-posters for MAIA (MAIA)?

The e-posters are available at maiabiotech.com/publications.

Did the reported 30-month patient continue treatment beyond two years?

No; the patient concluded therapy after reaching the protocol maximum treatment duration of two years.

Does the ESMO 2025 news confirm ateganosine efficacy for all ICI-resistant NSCLC patients?

No; MAIA presented individual extended survival data and both trials remain in progress without definitive cohort-level outcomes.