MAIA Biotechnology has reported that treatment with THIO (6-thio-dG or 6-thio-2’-deoxyguanosine) in sequential combination with cemiplimab (Libtayo) offered 100% disease control rate (DCR) for patients with second-line non-small cell lung cancer (NSCLC) in a Phase II clinical trial.

Dubbed THIO-101, the open-label, multicentre, dose-finding Phase II trial is assessing the anti-tumour activity of THIO following PD-(L)1 inhibition. 

It is analysing whether low doses of THIO given before cemiplimab, an anti-PD-1 of Regeneron, can improve immune responses in advanced NSCLC patients.

The patient population includes individuals who were unresponsive or resistant to a checkpoint inhibitor, as well as those whose cancer advanced following first-line checkpoint inhibitor treatment.

According to the positive initial efficacy trial findings, preliminary DCRs of 100% and 88% were reported in second-line and third-line trial subjects, respectively.

DCRs across all tested dose levels met the defined statistical thresholds earlier than predicted, allowing the expedition of the trial to the next stage.

THIO is an investigational, telomere-targeting agent in the clinical development stage.

MAIA Biotechnology CEO Vlad Vitoc said: “We have also observed unprecedented high DCRs in third-line, with an 88% control rate, with treatment of THIO followed by cemiplimab. 

“The results are even more remarkable given patients in this population have previously failed treatment with a checkpoint inhibitor. 

“These exceptional preliminary results underscore our confidence in advancing the trial to bring our novel treatment to advanced-stage NSCLC patients.”

In April this year, the company reported positive topline data from Part A of the Phase ll THIO-101 trial of THIO to treat advanced NSCLC.