Ateganosine Combo Exhibits Favorable Efficacy vs SOC in Advanced NSCLC

Among 79 patients treated with the ateganosine-based combination, 10 patients achieved a partial response per RECIST v1.1 criteria, 8 of whom had a confirmed PR by a second scan.

The combination of ateganosine (THIO) plus cemiplimab (Libtayo) exhibited durable activity as a third-line treatment in adult patients with advanced non–small cell lung cancer (NSCLC) resistant to immune-checkpoint inhibitor (ICI) therapy, according to findings from the phase 2 THIO-101 trial (NCT05208944) presented at the 2025 World Conference on Lung Cancer.¹

Among 79 patients treated with the ateganosine-based combination, 10 patients achieved a partial response (PR) per RECIST v1.1 criteria, 8 of whom had a confirmed PR by a second scan. Additionally, 36 patients had a survival follow-up of at least 12 months, with treatment or follow-up ongoing in 13 patients as of the data cut-off date of June 30, 2025. Notably, 2 patients completed thirty-three 3-week cycles of therapy.

In the third-line setting (n = 22), which was the focus of the presentation, the median overall survival (OS) was 17.8 months with a 95% CI lower bound of 12.5 months. The disease control rate (DCR) was 77% in this population compared with 25% to 35% in the same population of patients treated with chemotherapy. Additionally, patients treated with 180 mg of ateganosine in the third-line setting (n = 10) displayed an estimated progression-free survival (PFS) of 5.6 months, with a comparable PFS threshold of 2.5 months.

“[The phase 2 THIO-101 trial] continues to reveal impressive efficacy with an observed PFS of 5.6 months, which is more than double the standard of care PFS of just 2.5 months. The data also demonstrates the durability of ateganosine treatment through extended treatment cycles, which is in line with consistent tolerability and low toxicity,” said Vlad Vitoc, MD, chief executive officer and chairman of MAIA Biotechnology, the developers of ateganosine, said in a news release on the trial findings.² “We are seeking further validation of ateganosine’s strong efficacy in our THIO-101 Phase 2 expansion trial, which began enrolling patients in July 2025.”

The phase 2 dose-optimization study used a modified 3 + 3 design, with a safety lead-in enrolling 10 patients who received 120 mg of daily ateganosine on days 1 and 3 and 350 mg of cemiplimab on day 5 of 3-week cycles. Once the safety lead-in concluded, enrollment for the dose-finding portion of the study began. Thereafter, patients were assigned to receive 360 mg, 180 mg, or 60 mg of ateganosine plus cemiplimab every 3 weeks for a maximum of 1 year, and enrollment was completed in February 2024.A total of 79 patients received at least 1 dose of ateganosine, including 24 treated with 60 mg and 14 patients treated with 360 mg.

Among all patients treated with ateganosine, the median age was 67 years (range, 45%-85%), and most patients were men (65%). Most patients received 1 (66%) or 2 (28%) prior lines of therapy, had an ECOG performance status of 1 (73%), and had non-squamous histology. Brain and liver metastases were present in 5% and 15% of patients, respectively.

The primary end points of the phase 2 dose-optimization study were safety and objective response rate (ORR), and DCR. Secondary end points included duration of response, PFS, and OS. Exploratory end points included pharmacokinetics and pharmacodynamics.

Safety findings revealed that the investigational combination was well-tolerated, with most events being grade 1 or 2 in severity. Additionally, no dose-limiting toxicities were reported during the safety lead-in of the study. Grade 3 or higher treatment-emergent adverse effects (TEAEs) occurred in 21.5% of patients, including 9.8% of the 180 mg cohort.

The most common TEAEs included an aspartate aminotransferase (AST) increase (27%), an alanine aminotransferase (ALT) increase (23%), nausea (13%), anemia (11%), hyponatremia (10%), and weight loss (10%). Common grade 3 TEAEs were ALT and AST increased (11.4% each), followed by neutropenia (3.8%). Of note, enrollment in the 360 mg arm was paused after a grade 4 incidence of elevated liver function was identified.

References

1. 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
2. MAIA Biotechnology highlights positive efficacy data from THIO-101 phase 2 clinical trial in non-small cell lung cancer. News release. MAIA Biotechnology. September 11, 2025. Accessed September 12, 2025. https://tinyurl.com/murbzw5h