• THIO followed by cemiplimab shown to be well tolerated throughout trial, with far lower toxicity compared to standard of care treatments
• 6 patients on trial regimen for more than 12 months have completed up to 21 cycles, with treatment ongoing

CHICAGO / Jul 23, 2024 / Business Wire / MAIA Biotechnology, Inc., (NYSE American: MAIA) (“MAIA”, the “Company”), a clinical-stage biopharmaceutical company developing targeted immunotherapies for cancer, today announces positive treatment updates from its Phase 2 clinical trial, THIO-101, evaluating THIO sequenced with the immune checkpoint inhibitor (CPI) cemiplimab (Libtayo®) in patients with advanced non-small cell lung cancer (NSCLC) who failed two or more standard-of-care therapy regimens.

The trial’s therapeutic regimen is cycled every 3 weeks, with THIO 180mg administered in 60mg incremental doses on days 1, 2 and 3, followed by immune activation on day 4 (no dosing), and cemiplimab 350mg administered on day 5. As of the latest clinical cutoff date, June 12, 2024:

• 6 patients remain on treatment following at least 12 months of therapy.
• Treatment with THIO followed by cemiplimab has been well tolerated throughout the trial, with much lower toxicity compared to standard-of care treatments.
• Continuing treatment past 12 months demonstrates safety, efficacy and ongoing benefit from MAIA’s novel telomere targeting NSCLC therapy.

“Our longest treated patient so far has completed 21 cycles of THIO sequenced with a CPI, and 6 patients who have crossed the 12-month survival follow-up are continuing the treatment,” said Vlad Vitoc, M.D., Chairman and Chief Executive Officer of MAIA. “With current therapies, second-line patients’ treatment duration is usually around 3-4 months¹ and third-line is even lower than that. It is very encouraging to see that our patients can remain on treatment for much longer. The ongoing benefits of THIO in longer-term patients are particularly notable, signifying THIO’s potential as a durable and efficacious treatment for advanced NSCLC patients faced with limited options.”

1. https://www.sciencedirect.com/science/article/pii/S0169500217304373

About THIO

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 (THIO) induces telomerase-dependent telomeric DNA modification, DNA damage responses, and selective cancer cell death. THIO-damaged telomeric fragments accumulate in cytosolic micronuclei and activates both innate (cGAS/STING) and adaptive (T-cell) immune responses. The sequential treatment with THIO 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. THIO 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, a 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 THIO’s anti-tumor activity when followed by PD-(L)1 inhibition. The trial is testing the hypothesis that low doses of THIO 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 THIO administered as an anticancer compound and a priming immune activator (2) to assess the clinical efficacy of THIO using Overall Response Rate (ORR) as the primary clinical endpoint. Treatment with cemiplimab (Libtayo®) followed by THIO has been generally well-tolerated 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 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

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