MAIA Biotechnology, Inc. has filed a preliminary prospectus for the resale of 751,879 shares of common stock. The filing, dated September 25, 2026, details an offering by a selling stockholder who received these shares under a clinical trial funding agreement.

The shares were issued to PoC Capital, LLC pursuant to an agreement dated August 29, 2026. MAIA Biotechnology will not receive any proceeds from the sale of these shares by the selling stockholder.

Offering structure and regulatory basis

The prospectus describes the general manner in which the shares may be offered and sold from time to time. Specific details regarding the manner of sale will be provided in supplements to the prospectus if necessary. The shares were originally issued in connection with a private placement under Section 4(a)(2) of the Securities Act of 1933 and/or Regulation D.

Key transaction details

This resale registration does not constitute new capital for MAIA Biotechnology. The transaction solely facilitates liquidity for PoC Capital, LLC regarding its existing equity position acquired through the clinical trial funding arrangement.

MAIA Biotechnology, Inc. (NYSE: MAIA) has received regulatory approval from Spain’s AEMPS and Portugal’s INFARMED to begin screening patients for its pivotal Phase 3 THIO-104 clinical trial in non-small cell lung cancer (NSCLC). This expansion targets 100 patients dosed by year-end 2026, advancing the study toward a key interim survival analysis scheduled for 2027.

The inclusion of Spanish and Portuguese sites broadens the geographic footprint of the trial, which evaluates the efficacy of THIO-104, an immunotherapy candidate developed by MAIA. Vlad Vitoc, M.D., Chairman and Chief Executive Officer of MAIA, stated that establishing sites in these nations broadens access to a potentially important new treatment option for patients with advanced NSCLC who have progressed following standard of care treatments.

Market Context and Disease Burden

Spain and Portugal represent significant European markets for NSCLC treatment. The source data indicates an estimated 30,000 new cases annually across the two countries. This patient pool provides a substantial cohort for clinical recruitment and potential future commercialization.

Specific epidemiological factors highlight the relevance of these regions:

• Spain: The country faces a substantial lung cancer burden linked to historical tobacco exposure. Notably, lung cancer incidence among women in Spain continues to rise.
• Portugal: NSCLC accounts for approximately 82% of all lung cancer cases in Portugal. This is the highest proportion reported among five European populations evaluated in a comparative study cited by the company.

Trial Progression and Enrollment Status

To date, THIO-104 has enrolled 65 NSCLC patients resistant to chemotherapy and checkpoint inhibitor treatments at 28 clinical sites in six European countries and 10 sites in Taiwan. Among the six European countries, sites in Hungary, Poland, and Turkey are actively enrolling and dosing patients from populations with the highest lung cancer incidence and mortality rates in Europe and globally.

The regulatory clearances from AEMPS and INFARMED allow the immediate commencement of patient screening at sites within these nations. The pivotal nature of the Phase 3 trial underscores its importance in the regulatory pathway for THIO-104, with the 2027 interim analysis serving as a critical milestone for assessing survival benefits.

What the Numbers Show

The combined enrollment data reveals a strategic geographic diversification. With 65 patients currently enrolled across 38 total sites (28 in Europe, 10 in Taiwan), the addition of Spanish and Portuguese sites is critical to reaching the target of 100 patients by year-end 2026. The requirement to add 35 more patients in less than four months suggests an aggressive acceleration in recruitment velocity compared to the historical pace implied by the current count.