Dimerix Limited (ASX: DXB) has announced the completion of patient recruitment for the second part of its pivotal ACTION3 Phase 3 clinical trial evaluating DMX-200 in patients with Focal Segmental Glomerulosclerosis (FSGS). The trial, a multi-center, randomized, double-blind, placebo-controlled study, aims to assess the efficacy and safety of DMX-200 in FSGS patients receiving a stable dose of an angiotensin II receptor blocker (ARB). With the first 144 patients now randomized, a blinded interim analysis is scheduled for August 2025.
ACTION3 Trial Design and Objectives
The ACTION3 trial is designed to evaluate DMX-200's impact on proteinuria and kidney function, measured by eGFR slope, with the goal of generating sufficient evidence for marketing approval. Patients enrolled in the trial are receiving either DMX-200 (120 mg capsule twice daily) or a placebo, in addition to a stable dose of an ARB. The trial's design incorporates interim analysis points to capture early evidence of efficacy.
Dr. Nina Webster, CEO and Managing Director of Dimerix, stated that the randomization of the first 144 patients is a major milestone, triggering the planned blinded data collection in August 2025. The company anticipates completing full recruitment for the study, targeting a total of 286 patients, in Q3 2025.
DMX-200 and FSGS Treatment Landscape
FSGS is a rare and progressive kidney disease characterized by irreversible scarring, leading to kidney damage and eventual end-stage kidney failure, often requiring dialysis or transplantation. Currently, there are no approved treatments specifically for FSGS, making DMX-200 a potential breakthrough therapy.
DMX-200, also known as QYTOVRA, is designed to reduce inflammation in the kidney, preventing scarring and fibrosis. It functions as an adjunct therapy, administered alongside blood pressure medication. The drug has received Orphan Drug Designation in the US and Europe, which provides regulatory and financial benefits, including reduced fees and market exclusivity.
Potential for Accelerated Approval and Market Opportunity
Subject to regulatory guidance, Dimerix may pursue accelerated approval for DMX-200 in key territories, potentially enabling commercial launch before the completion of the two-year ACTION3 trial. The FSGS market is substantial, with approximately 220,000 people affected worldwide. Dimerix has already secured licensing deals for DMX-200 in Europe, Canada, Australia, New Zealand, and the Middle East, valued at A$350 million in upfront and potential milestone payments, plus royalties.
Open Label Extension Study
Dimerix has also implemented an open-label extension (OLE) study, allowing patients who complete the ACTION3 trial to continue receiving DMX-200 for an additional two years. This provides further long-term data and ensures continued access to the experimental treatment. To date, 14 patients have transitioned into the OLE study.
