Highlights

  • The first patient has completed four years of continuous participation in Dimerix’s DMX-200 clinical development program.
  • The patient completed the two-year ACTION3 Phase 3 trial followed by a two-year Open Label Extension study.
  • Of 96 patients who have completed ACTION3 to date, 89 entered the extension study, representing a 93% continuation rate.
  • The adult ACTION3 cohort is fully recruited with 333 patients randomised and dosed across 219 sites in 21 countries.

Dimerix Limited (ASX:DXB) is a clinical-stage biopharmaceutical company developing therapies for kidney diseases with significant unmet medical need. DXB shares were quoted at A$0.24 on 5 October 2026. Its lead program, DMX-200, is in Phase 3 development for focal segmental glomerulosclerosis, or FSGS, while the company is also advancing DMX-652 through a Phase 2 program in acute kidney injury.

First Patient Completes Four Years in DMX-200 Program

On 5 October 2026, Dimerix announced that the first patient had completed the company’s two-year Open Label Extension study after previously completing the two-year blinded ACTION3 Phase 3 trial.

This marks four years of continuous participation in the DMX-200 clinical development program. The extension study is designed to collect longer-term safety and efficacy information from patients who complete ACTION3 and choose to continue treatment.

All participants in the extension study receive DMX-200, regardless of whether they received DMX-200 or placebo during the blinded Phase 3 portion.

Extension Study Records 93% Continuation Rate

Dimerix reported that 96 patients had completed the ACTION3 Phase 3 study at the date of the announcement. Of these, 89 elected to continue into the Open Label Extension study.

That equates to a continuation rate of 93%. Participation in the extension is optional for eligible patients following completion of the blinded Phase 3 study.

The extension study can provide additional information about DMX-200 over a longer treatment period. Dimerix stated that such data may support future regulatory and commercial activities, although the update does not report new comparative efficacy results from the extension program.

Post-Trial Access Program Being Prepared

Patients completing the two-year extension study are expected to be offered continued access to DMX-200 through a Post-Trial Access program once relevant ethics approvals have been obtained.

Dimerix and its commercial partners are seeking approval for the program in territories that recruited ACTION3 patients. Continued treatment through this program would follow approximately four years of participation across the Phase 3 and extension studies.

The announcement does not state that those ethics approvals have yet been granted.

ACTION3 Adult Cohort Fully Recruited

The global ACTION3 study remains ongoing. The adult cohort has been fully recruited, with 333 patients randomised and dosed across 219 sites in 21 countries.

The final adult patient commenced treatment in March 2026, moving the study from recruitment into the treatment and follow-up phase. Dimerix expects the final adult patient to complete dosing in March 2028. Recruitment of patients aged 12 to 17 years continues separately within the paediatric cohort.

ACTION3 is designed as a multicentre, randomised, double-blind, placebo-controlled Phase 3 study. Patients receive either DMX-200 at 120mg twice daily or placebo while remaining on a stable dose of an angiotensin II receptor blocker.

Study Designed to Assess Proteinuria and Kidney Function

The Phase 3 program is designed to measure both proteinuria and kidney function through eGFR slope.

These measures are intended to provide the clinical evidence required to support potential Marketing approval if the study outcomes are successful.

DMX-200 is a CCR2 antagonist administered alongside standard angiotensin II type I receptor blocker therapy. The company has Patent protection in various territories through 2032, with additional applications that may extend protection to 2042.

The 5 October release does not provide updated revenue, Earnings or cash-flow figures, so there is no new year-on-year financial increase or decline to assess from this announcement.

Closing Perspective

Dimerix’s latest update is centred on duration of patient participation and continued follow-up rather than a new efficacy readout. The first four-year completion provides additional long-term exposure data, while the 93% continuation rate shows that most eligible patients completing ACTION3 have chosen to enter the extension study. The adult Phase 3 cohort remains fully recruited, with treatment and follow-up continuing toward the final planned dosing completion in March 2028.