Aclaris Therapeutics’ ATI-052 antibody shows PK efficacy in Phase 1a trial

Aclaris Therapeutics (ACRS) provided a clinical update on its biologic and oral inhibitor compounds including positive full top line results from the first-in-human Phase 1a single and multiple ascending dose trial of its anti-TSLP/IL-4Ralpha bispecific antibody ATI-052, and the selection of lichen planus, or LP, as the lead indication for its selective ITK/JAK3 inhibitor ATI-2138. Aclaris is progressing ATI-052 through two proof-of-concept studies and plan to initiate a Phase 2b program in Q4. By addressing the shared receptor IL-4Ralpha, ATI-052 blocks IL-4 and IL-13 biological activity, key cytokines driving Th2 inflammation. The update provides full top line results including: ATI-052 exhibited a potential best-in-class pharmacokinetic, or PK, profile, including an estimated half-life of approximately 45 days. Dose proportional PK was observed across the pharmacologic dose range. Pharmacodynamic, or PD, results validate the potency of ATI-052. ATI-052 demonstrated complete and sustained inhibition through at least week 20 and at least week 12 in the 480 mg MAD cohort. The combination of the strong and sustained PK duration and PD effect supports the potential for up to every three-month dosing. ATI-052 was well tolerated and demonstrated a favorable safety profile across all SAD and MAD cohorts, consistent with the interim results. The company intends to initiate a Phase 2b program with ATI-052, initially targeting asthma, in Q4.