Ateganosine Combo Demonstrates Disease Control in Third-Line NSCLC

Ateganosine (THIO) followed by cemiplimab (Libtayo) produced disease control in patients with third-line advanced non–small cell lung cancer (NSCLC), according to a news release from MAIA Biotechnology on initial efficacy data from Part C of the phase 2 THIO-101 trial (NCT05208944).¹

What did the THIO-101 Part C data show?

In the Part C expansion phase of the study, patients received ateganosine followed by cemiplimab in 21-day cycles. Across the efficacy-evaluable population, the interim disease control rate (DCR) was 90.5% (n = 19/21). The results appeared to be consistent with the efficacy signals previously reported for Parts A and B of THIO-101, which included an 88% DCR in patients with third-line NSCLC. By comparison, current chemotherapy regimens produce an approximate DCR of 25% to 35% in this setting.

Investigators noted that the combination has shown an acceptable safety profile to date in this heavily pretreated population. Additionally, international enrollment for Part C has been completed.

Patients enrolled in Part C represented a more heavily pretreated population than earlier cohorts. All patients had previously received docetaxel and had demonstrated resistance to both immunotherapy and other chemotherapies.

“The initial efficacy data from the Part C studies are consistent with the encouraging efficacy signals we previously reported for Parts A and B of THIO-101, including an 88% [DCR] in [patients with] third-line NSCLC,” said Vlad Vitoc, MD, founder and chief executive officer of MAIA Biotechnology, in the press release.¹ “This measure of efficacy is close to triple the reported outcome for standard-of-care chemotherapy treatment.”

What did earlier THIO-101 cohorts demonstrate?

Previous data from the THIO-101 trial were presented at the 2025 World Conference on Lung Cancer.² In the third-line setting (n = 22), the median overall survival (OS) was 17.8 months, and the DCR was 77%. Patients treated with 180 mg of ateganosine in the third-line setting (n = 10) had an estimated progression-free survival (PFS) of 5.6 months vs a comparator threshold of 2.5 months.

In the earlier dose-optimization portion of the trial, the combination was well tolerated. Most treatment-emergent adverse events (TEAEs) were grade 1 or 2, and grade 3 or higher events occurred in 21.5% of patients.

What is ateganosine, and how does the THIO-101 trial work?

Ateganosine is a first-in-class investigational telomere-targeting agent that induces telomerase-dependent telomeric DNA damage and selective cancer cell death while activating innate and adaptive immune responses. The sequential administration of ateganosine followed by PD-(L)1 inhibition is intended to enhance and prolong the antitumor immune response.

THIO-101 is a multicenter, open-label phase 2 trial evaluating ateganosine followed by cemiplimab in patients with advanced NSCLC who did not respond to or progressed after a prior checkpoint inhibitor–containing regimen.³ The primary end points include dose-limiting toxicities, objective response rate, and DCR. Secondary end points include duration of response, PFS, OS, and incidence of TEAEs.

Patients 18 years and older with histologically or cytologically confirmed NSCLC that has relapsed or progressed following treatment in the advanced setting, no prior targeted therapy for driver mutations, and at least 1 measurable lesion per RECIST v1.1 guidelines were eligible for enrollment on the trial. Other eligibility criteria included having an ECOG performance status of 0 or 1 and adequate organ function. Those with untreated or symptomatic central nervous system metastases, active gastrointestinal bleeding through hematemesis or melena, or another concurrent malignancy were ineligible for enrollment.

References

1. MAIA Biotechnology reports strong initial efficacy data in third-line non-small cell lung cancer from phase 2 THIO-101 Part C expansion trial. News release. MAIA Biotechnology, Inc. July 8, 2026. Accessed July 9, 2026. https://tinyurl.com/4csz9mc4
2. Jankowski T, Kowal-Rosinska M, Urban L, et al. Study of THIO sequenced with cemiplimab in 3rd line immune checkpoint inhibitor-resistant aNSCLC: improvement in PFS. Presented at: IASLC 2025 World Conference on Lung Cancer; September 6-9, 2025; Barcelona, Spain. Abstract 2694.
3. A study of THIO sequenced with cemiplimab in advanced NSCLC (THIO-101). ClinicalTrials.gov. Updated May 13, 2026. Accessed July 8, 2026. https://tinyurl.com/mty8d54h