Inhibikase Therapeutics Announces Plans To Advance Its PAH Therapeutic Candidate, IKT-001, Into A Global Phase 3 Trial And Is Expected To Begin In Q1 2026

Inhibikase Therapeutics, Inc. (NASDAQ:IKT) ("Inhibikase" or "Company"), a clinical-stage pharmaceutical company developing therapeutics to modify the course of cardiopulmonary diseases namely, Pulmonary Arterial Hypertension ("PAH"), today announced that it expects to advance IKT-001 to a global pivotal Phase 3 clinical study in PAH. The Phase 3 study, named IMPROVE-PAH (IKT-001 for Measuring Pulmonary Vascular Resistance and Outcome Variables in a Phase 3 Evaluation of PAH), is expected to be initiated in the first quarter of 2026.

IKT-001 is an investigational novel pro-drug of imatinib mesylate ("imatinib"). Imatinib is an anti-proliferative tyrosine kinase inhibitor, TKI, with potential best-in-class improvements in pulmonary vascular resistance ("PVR") and 6-minute walk distance ("6MWD") of 45 meters(1) based on Phase 3 IMPRES and Phase 2 studies(2). Despite the IMPRES Phase 3 study of imatinib demonstrating improved exercise capacity and hemodynamics in patients with advanced PAH, high discontinuations impacted the results. IKT-001 is a prodrug of imatinib which is engineered to realize the potential of imatinib in PAH and lower discontinuations in the forthcoming Phase 3 study.

The Company previously planned to initiate a Phase 2b study in 150 subjects in PAH prior to advancing to a pivotal Phase 3 study. However, the Company submitted a Type C Meeting request to the U.S. Food & Drug Administration ("FDA") to, among other things, obtain feedback on an immediate transition to a pivotal Phase 3 study design. 

Following receipt from the FDA of the Written Response from the Type C interaction, the Company now plans to initiate a two-part adaptive Phase 3 study. We expect Part A of IMPROVE-PAH will be a double blind, placebo-controlled study in 140 patients with a primary endpoint of PVR at Week 24. We expect Part B will adopt an identical format to Part A except the primary endpoint will be 6MWD at Week 24 in 346 patients. We believe this adaptive Phase 3 study design has important advantages including; (1) permitting a 12-week dose-titration phase designed to get patients to the highest tolerable dose of IKT-001; (2) uninterrupted enrollment between Part A and Part B; and (3) the ability to, if necessary, undertake a sample size re-estimation for Part B based on Part A findings. Given the Company was well-advanced in initiating the previous Phase 2b study design, the Company expects to initiate IMPROVE-PAH in the first quarter of 2026, with this study expected to be conducted in up to approximately 180 sites around the world.