Dimerix (ASX:DXB) has provided an update on its ACTION3 Phase 3 clinical trial of DMX-200 in a rare kidney disease.
The company held a Type C meeting with the US FDA in March. The FDA has accepted proteinuria as an appropriate primary endpoint for full marketing approval in the US for DMX-200 in Focal Segmental Glomerular Sclerosis (FSGS).
The company said the FDA agreed that suitable proteinuria endpoints could include a statistically significant increase in the proportion of patients achieving a defined proteinuria reduction compared to the placebo arm after two-years of treatment as proposed by the PARASOL working group, or a statistically significant decrease in proteinuria from baseline compared to the placebo arm after two-years of treatment, along with a justification for what constitutes a meaningful difference between treatment arms.
Dimerix said the FDA noted that this justification should be data-driven and provided well before the trial's completion.
The FDA further proposed that if proteinuria is used as a primary endpoint, the existing eGFR slope change endpoint should be pre-specified as a secondary endpoint. Proteinuria is known to demonstrate less variability than eGFR for clinical trials and could, therefore, reduce risk for potential downstream marketing approval in the US.
Dimerix said the FDA also confirmed that they remain open to discussing endpoints that could support a potential Accelerated Approval application and verify clinical benefit.
Dimerix CEO and managing director Dr Nina Webster said, “The agreement with the FDA on proteinuria as an appropriate primary endpoint for full marketing approval for DMX-200 in our phase 3 trial is an exceptional outcome, particularly given that DMX-200 has previously demonstrated positive effects on this endpoint in both pre-clinical and clinical studies. As part of our study design, both eGFR and proteinuria data are being collected for a total of 2 years however the FDA response on proteinuria potentially gives us an opportunity for earlier market entry by working with both PARASOL and FDA on an accelerated approval proteinuria endpoint for use in FSGS. There remains a high unmet need for new treatments for this progressive disease, and studies such as ACTION3 provide hope for those patients desperately in need of treatment options.”
