MAIA Biotechnology, Inc. (NYSE: MAIA) has completed international enrollment in Part C of its Phase 2 THIO-101 expansion trial evaluating its lead candidate, ateganosine, in advanced non-small cell lung cancer (NSCLC) patients receiving third-line (3L) therapy. Ateganosine is an investigational dual-mechanism therapy targeting telomeres and immune activation in difficult-to-treat cancers. The trial enrolled 41 patients across Taiwan, Turkey, Poland, Hungary, Romania, and Georgia.

Trial Design and Objectives

THIO-101 Part C patients, who are resistant to prior checkpoint inhibitor therapy and chemotherapy, are randomized between MAIA’s proposed combination regimen of ateganosine followed by cemiplimab and treatment with ateganosine alone for two cycles. The trial is a multicenter, open-label, dose finding Phase 2 clinical trial designed to evaluate ateganosine’s anti-tumor activity when followed by PD-(L)1 inhibition.

Key Clinical Data

In Parts A and B of THIO-101, MAIA reported data showing median survival of 17.8 months. Overall survival beyond two years was observed for eight patients in Parts A and B; these patients did not receive subsequent lines of therapy. One patient in this cohort receiving third-line therapy has survived for over 33 months. Expected survival in this heavily pre-treated population is 5.8 months.

Regulatory Status and Future Steps

The FDA has granted Fast Track designation for ateganosine in non-small cell lung cancer treatment, potentially expediting the regulatory process to a potential Accelerated Approval and Priority Review. Patient screening is ongoing at three activated clinical sites in the United States. The trial’s primary objectives are to evaluate the safety and tolerability of ateganosine and to assess clinical efficacy using Overall Response Rate as the primary endpoint.

MAIA Biotechnology, Inc. has activated its second U.S. clinical site for the Phase 2 THIO-101 expansion trial at Central Alabama Research in Homewood, Alabama. The expansion part of THIO-101 evaluates ateganosine, a dual-action molecule, as a third-line treatment for non-small cell lung cancer (NSCLC) in patients who have previously failed treatment with checkpoint inhibitors and chemotherapy. The additional data from the trial's expansion may further support an accelerated approval filing with the FDA.

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. Parts A and B of the Phase 2 trial provided key inputs for MAIA's market strategy by identifying optimal dosing for a well-defined patient population. The trial operates under FDA Fast Track designation.

Clinical Trial Details

The Phase 2 clinical trial is a multicenter, open-label, dose finding study designed to evaluate ateganosine's anti-tumor activity when followed by PD-(L)1 inhibition. The trial tests the hypothesis that low doses of ateganosine administered prior to cemiplimab will enhance and prolong immune response in patients with advanced NSCLC who previously did not respond or developed resistance after first-line treatment.

Phase 3 Trial Progress

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. The Phase 3 trial features 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 for NSCLC. The modified nucleotide 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 and adaptive immune responses.