MAIA Biotechnology, Inc. (NYSE American: MAIA) has announced promising clinical progress for its lead candidate, THIO (6-thio-dG or 6-thio-2’-deoxyguanosine), in a Phase 2 clinical trial (THIO-101) for advanced non-small cell lung cancer (NSCLC). The trial evaluates THIO, a potential first-in-class cancer telomere targeting agent, in combination with the immune checkpoint inhibitor cemiplimab in patients who have failed two or more prior standard-of-care regimens. The data, as of April 30, 2024, indicates that THIO demonstrates encouraging disease control and response rates, potentially offering a new treatment avenue for this patient population.
THIO-101 Trial Results
The Phase 2 THIO-101 trial is a multicenter, open-label study designed to assess the safety, tolerability, and efficacy of THIO when administered prior to PD-(L)1 inhibition with cemiplimab (Libtayo®). The trial enrolled patients with advanced NSCLC who had progressed after prior treatment with a checkpoint inhibitor. Key findings from the THIO-101 trial include:
- Overall Response Rate (ORR): 38%
- Disease Control Rate (DCR): 85%
- Median Progression-Free Survival (PFS): 5.5 months
- Median Survival Follow-Up Time: 9.1 months
These results pertain to the THIO 180mg + CPI (cemiplimab) arm in the third-line treatment setting. According to MAIA Biotechnology, the observed efficacy of THIO significantly outperforms reported standard-of-care data in NSCLC for this heavily pre-treated population.
Mechanism of Action and Clinical Significance
THIO's dual mechanism of action involves inducing telomeric DNA damage and boosting cancer-specific immune responses. By targeting telomeres, which play a crucial role in cancer cell survival and resistance, THIO aims to selectively kill cancer cells and activate both innate (cGAS/STING) and adaptive (T-cell) immune responses.
Vlad Vitoc, M.D., MAIA’s Chairman and Chief Executive Officer, noted that THIO has demonstrated an excellent safety profile across all doses, with the 180mg dose showing the greatest efficacy and tolerability compared to existing therapies. He emphasized the unmet medical need in checkpoint inhibitor-resistant and platinum-resistant NSCLC patients, stating, "We believe that our trial is providing the first real dataset in CPI-resistant patients like this. We are confident about THIO’s prospects for substantially extending patient survival and establishing a new standard of care for cancer."
Financial Position and Future Development
MAIA Biotechnology reported a significantly improved cash position, with $8.7 million in cash and current assets as of March 31, 2024. The company has raised approximately $12.4 million since February 2024 through private placements and sales under its at-the-market offering facility, with a substantial portion allocated to fund the continuing clinical development of THIO. The Phase 2 THIO-101 clinical trial is expected to near completion in 2024, and MAIA is also engaged in research and development for a portfolio of second-generation THIO-like compounds.
