Third Arc Bio Begins Dosing First Patient in Phase 1 Trial for ARC101 T Cell Engager in CLDN6 Positive Cancers

Third Arc Bio Inc., a progressive biotech company engaged in the development of innovative multifunctional antibodies for oncology and immunology applications, has commenced a groundbreaking clinical trial. The trial focuses on ARC101, the firm's inaugural bispecific antibody aimed at targeting Claudin 6 (CLDN6). In a significant milestone, the first subject has been treated in this pioneering first-in-human study, which is designed to assess ARC101's safety profile, dosage optimization, pharmacokinetics, and initial antitumor effects.

ARC101 distinguishes itself as a best-in-class T cell engager due to its exceptional specificity for CLDN6, a trait that sets it apart from other Claudin proteins. The study, identified as a Phase 1 trial, is dedicated to patients who present with locally advanced or metastatic solid tumors that express CLDN6. The primary objectives include determining the safety, tolerability, and optimal dosing of ARC101 when administered as a monotherapy. Furthermore, the trial will evaluate the pharmacokinetic and pharmacodynamic properties of ARC101 and its preliminary efficacy in combating tumors.

Peter F. Lebowitz, both the Chief Executive Officer and Chief Medical Officer of Third Arc Bio, expressed enthusiasm for this clinical advancement. He emphasized the significance of ARC101's clinical trial as a transformative step for the company, marking its evolution into a clinical-stage entity. Dr. Lebowitz highlighted ARC101's promising potential to achieve a superior therapeutic index in clinical settings, given its precise targeting capability. He also noted that the company is actively advancing additional programs toward clinical trials through essential IND-enabling studies, building upon the foundation laid by ARC101.

ARC101 represents Third Arc Bio's initial foray into clinical evaluations involving human subjects for its immune cell engaging antibodies. These antibodies are designed to modulate the immune system with precision, targeting specific disease conditions. The company is committed to furthering its Synergy Platform, which underpins the development of an innovative pipeline of multispecific drugs aimed at targeting CD3 and CD28, with the ultimate goal of creating transformative therapies for solid tumors.

In line with its commitment to transparency and scientific advancement, Third Arc Bio is preparing to present its preclinical findings for ARC101 at the upcoming 2025 American Association for Cancer Research (AACR) Annual Meeting. This presentation will underscore ARC101's superior specificity for CLDN6, distinguishing it from other closely related Claudin proteins.

Third Arc Bio's organizational mission centers around the creation of multifunctional antibodies that precisely modulate immune responses by either activating or inhibiting T cells. Through the deployment of advanced technologies, the company seeks to produce superior biologics that offer best-in-class T cell engagement. Its platforms include the solid tumor-focused Synergy Platform and the Immunology & Inflammation (I&I) Tethering Platform, both of which aim to provide precise immune regulation to ensure optimal efficacy and safety.

ARC101 is a cutting-edge T cell engager with a focus on solid tumors expressing CLDN6. It boasts high specificity without off-target effects, avoiding interaction with other Claudin proteins. Moreover, ARC101 features potent cytotoxic capabilities, a prolonged half-life, and favorable biophysical properties. Currently, ARC101 is being evaluated in Phase 1 clinical studies to determine its safety, tolerability, pharmacokinetics, and antitumor efficacy in patients dealing with advanced cancer.