The US Food and Drug Administration (FDA) has confirmed adolescent children can be recruited to Dimerix’s ACTION3 global Phase 3 Focal Segmental Glomerulosclerosis (FSGS) trial.

Dimerix (ASX:DXB) today announced details of a meeting with the FDA to discuss the paediatric plan for DMX-200 in Focal Segmental Glomerulosclerosis (FSGS) patients under 18 years old.

The meeting confirmed inclusion of paediatric adolescent patients aged 12 to 17 was appropriate in the current global ACTION3 Phase 3 study of DMX-200 for patients with FSGS, recognising its appropriate safety profile.

DMX said no change in dose or regime is required for the adolescent population.

The meeting provided clarity on the remaining development of DMX-200 required for paediatric patients under 12 with FSGS through to market approval, broadening the total addressable market if approved.

DMX is  also  in  discussions  with the  European  Medicines  Agency  (EMA)  regarding a  Paediatric Investigation  Plan  (PIP), required before  seeking  market  approval  in Europe.

The outcome of these discussions is expected in CY23.

FSGS leading cause of kidney failure in kids

FSGS is a rare disease attacks the kidney’s filtering units causing irreversible scarring. The scarring leads to permanent damage and eventual end-stage kidney failure, requiring   dialysis or transplantation.

For those fortunate enough to receive a kidney transplant, 60% of patients have reoccurring FSGS after the first kidney transplant.

FSGS affects both adults and children as young as two years old and is one of the leading causes of kidney failure in children, with 20% of child nephrotic syndrome cases caused by the disease.

There are presently no drugs specifically approved for FSGS anywhere in the world, leading to limited treatment options and poor prognosis.

ACTION 3 trial progressing well

The pivotal Phase  3  trial is titled Angiotensin  II  Type  1  Receptor  (AT1R)  & Chemokine  Receptor  2 (CCR2) Targets  for Inflammatory Nephrosis – or  ACTION3  for  short.

It is a multi-centre, randomised,  double-blind,  placebo-controlled  trial of  the  efficacy  and  safety of DMX-200  inpatients with FSGS who are receiving a stable dose of an angiotensin II receptor blocker (ARB).

Once the ARB dose is stable, patients, aged now aged 12 to 80 years will be randomised to receive either DMX-200 (120 mg capsule twice daily) or placebo.

There are 90 adult patients currently recruited.  Interim analysis, assessing proteinuria reduction of the first 72 patients on DMX-200 versus placebo at week 35, is anticipated in the latter half of CY23.

All activated sites will continue to recruit suitable patients for Part 2 of the ACTION3 trial.

Large addressable market in need of treatment

The total global FSGS market was valued at US$12.6 billion in 2022 with a CAGR of 8.2%, driven by ~220,000  FSGS  sufferers  across  the  7  major  markets and  premium  orphan  drug pricing.

DMX-200 has previously received Orphan Drug Designation with the FDA, EMA, and UK, allowing potential fast track of commercialisation if successful.

DMX CEO and Managing Director Dr Nina Webster the FDA have consistently encouraged Dimerix to develop DMX-200 for children given the very poor prognosis in the disease and lack of targeted therapies.

“This formal meeting with the FDA gave us a valuable opportunity to discuss our paediatric plans for DMX-200 in the US,” she said.

“We are very pleased to be able to open the study to adolescent patients later in the year, which may provide a viable treatment option for these younger patients if approved.

Webster said inclusion of adolescent patients will also increase the total pool of patients that could be recruited into Part 2 of the ACTION 3 study, potentially accelerating the rate of recruitment for the study.

“This initial discussion regarding adolescent enrolment in the ACTION3 study builds on numerous constructive discussions we have had with key regulatory agencies worldwide,” she said.

“We will continue discussions with the FDA to support development of new therapies in this population of adolescent patients who have very few therapeutic options currently available or in development.”

2023 looks set to be a busy year for the Aussie biotech which is also further progressing chronic obstructive pulmonary disease (COPD) and diabetic kidney disease programs along with supporting the investigator-led covid-19 programs.

This article was developed in collaboration with Dimerix, a Stockhead advertiser at the time of publishing.

This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.