Officials Provide Update on Phase 2 Trial of THIO Plus Cemiplimab in NSCLC

Continuing treatment with THIO plus cemiplimab (Libtayo) past 12 months “demonstrates safety, efficacy, and ongoing benefit” in patients with advanced non-small cell lung cancer (NSCLC) who experienced failure of 2 or more standard-of-care therapy regimens, according to an announcement from MAIA Biotechnology, Inc.

THIO, which is 6-thio-dG or 6-thio-2’-deoxyguanosine, is a first-in-class investigational telomere-targeting agent. The regimen of THIO plus cemiplimab is under evaluation in the multicenter, open-label, dose-finding, phase 2 THIO-101 clinical trial, which is the first trial designed to evaluate the antitumor activity of THIO followed by PD-(L)1 inhibition.

The trial’s primary objectives are to evaluate the safety and tolerability of THIO administered as an anticancer compound and a priming immune activator and assess the clinical efficacy of THIO using overall response rate as the primary clinical end point. The trial design cycles the treatment regimen every 3 weeks. Patients receive THIO 180 mg in 60-mg incremental doses on days 1, 2, and 3, followed by immune activation and no dosing on day 4. Patients receive cemiplimab 350 mg on day 5. Data from the latest clinical cutoff date, June 12, 2024, showed that 6 patients remained on treatment after at least 12 months of therapy.

The treatment regimen has “been well tolerated throughout the trial, with much lower toxicity compared [with] standard-of-care treatments,” according to company officials.

“Our longest treated patient so far has completed 21 cycles of THIO sequenced with a [checkpoint inhibitor], and 6 patients who have crossed the 12-month survival follow-up are continuing the treatment,” MAIA Chairman and CEO Vlad Vitoc, MD, said in a statement. “With current therapies, second-line patients’ treatment duration is usually around 3 to 4 months 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.”

For more information on the trial, visit ClinicalTrials.gov and search for the identifier NCT05208944.

Source: MAIA Biotechnology