Third Arc Bio Inc. has announced the dosing of the first patient in its Phase 1 clinical trial evaluating ARC101, a bispecific antibody targeting Claudin 6 (CLDN6) for the treatment of advanced cancers. This milestone marks the company's transition to a clinical-stage biotech organization.
The first-in-human study will assess the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary antitumor efficacy of ARC101 as a monotherapy in patients with locally advanced or metastatic solid tumors that express 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."
Mechanism of Action and Development Strategy
ARC101 represents Third Arc Bio's first clinical effort to evaluate its immune cell engaging antibodies in humans. The drug is designed to modulate the immune system in precise ways to target specific disease states. The company has optimized ARC101 as a T cell engager with high specificity for CLDN6, avoiding cross-reactivity with other members of the Claudin protein family.
The company plans to present preclinical data for ARC101 at the upcoming 2025 American Association for Cancer Research (AACR) Annual Meeting. These results will highlight the drug candidate's specificity for CLDN6 versus other closely related Claudin proteins, supporting its potential best-in-class profile.
Expanding Pipeline Development
While advancing ARC101 through clinical development, Third Arc Bio is simultaneously progressing additional programs toward the clinic with the execution of IND-enabling studies. The company is leveraging its proprietary Synergy Platform to develop novel CD3 and CD28 targeting multispecific antibodies for solid tumors.
"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," Dr. Lebowitz added.
About ARC101 and the Clinical Trial
ARC101 is designed as a potential best-in-class T cell engager specifically targeting solid tumors that express CLDN6. According to the company, the drug candidate exhibits:
- High specificity with no off-target binding
- Avoidance of other Claudin family proteins
- Potent cytotoxicity
- Long half-life
- Optimal biophysical properties
The Phase 1 study (NCT06672185) is currently enrolling patients with advanced cancer to assess the drug's safety profile, tolerability, pharmacokinetics, and potential antitumor activity.
Company Background
Third Arc Bio is developing multifunctional antibodies that generate immune synapses to precisely activate or inhibit T cells. The company's technology platforms include a solid tumor Synergy Platform and an immunology & inflammation (I&I) Tethering Platform, both designed to achieve superior efficacy and safety profiles.
The Spring House, Pennsylvania-based company is building a pipeline of therapeutics focused on both oncology and immunology & inflammation indications, with ARC101 representing its first clinical-stage asset.
