Third Arc Bio Announces First Patient Dosed in Phase 1 Clinical Trial of Lead T Cell Engager ARC101 to Treat CLDN6 Positive Cancers

On March 13, 2025 Third Arc Bio Inc., a clinical stage biotech company developing novel multifunctional antibodies for a range of oncology and immunology & inflammation (I&I) indications, reported the first patient has been dosed in its first-in-human study evaluating ARC101, a potential best-in-class T cell engager targeting Claudin 6 (CLDN6) (Press release, Third Arc Bio, MAR 13, 2025, View Source [SID1234651140]).

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

This Phase 1 study will evaluate the optimal dosing, safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD) and preliminary antitumor efficacy of ARC101 as monotherapy in patients with locally advanced or metastatic solid tumors expressing CLDN6.

"ARC101 is the first program from our growing pipeline to reach the clinic – signifying Third Arc Bio’s transition into a clinical stage company," said Peter F. Lebowitz, MD, PhD, Chief Executive Officer and Chief Medical Officer of Third Arc Bio. "Given ARC101’s remarkable specificity for CLDN6 over other Claudin proteins, we believe ARC101 has the potential to achieve a superior therapeutic index in the clinic. As we advance the ARC101 clinical program, we are also rapidly progressing our next programs towards the clinic with the execution of critical IND-enabling studies."

ARC101 represents the company’s first clinical effort to evaluate in humans its immune cell engaging antibodies that modulate the immune system in precise ways to target specific disease states. Building upon ARC101 as a foundation, Third Arc Bio continues to invest in its Synergy Platform to develop a pipeline of novel CD3 and CD28 targeting multispecifics to create transformational drugs against solid tumors.

Third Arc Bio will present a poster highlighting preclinical results for ARC101 at the upcoming 2025 American Association for Cancer Research (AACR) (Free AACR Whitepaper) Annual Meeting. The data will highlight ARC101’s best-in-class specificity for CLDN6 versus other closely related Claudin proteins.