Travere Therapeutics' Rare Kidney Disease Drug Disappoints In Phase 3 Study, Analyst Says Efficacy Trends Suggest Potential Path Forward

Travere Therapeutics Inc TVTX announced topline primary efficacy results from the Phase 3 DUPLEX Study of sparsentan in focal segmental glomerulosclerosis (FSGS). 

FSGS is a rare kidney disease defined by progressive scarring of the kidney resulting in proteinuria and rapid decline in kidney function. 

The study did not achieve its primary efficacy endpoint, with only a 0.3 mL/min/1.73m2 difference in eGFR total slope compared to active control irbesartan after 108 weeks and a 0.9 mL/min/1.73m2 difference on eGFR chronic slope.

Also Read: Additional Data From Travere Therapeutics' Kidney Disease Candidate Reinforce Efficacy, Supporting Ongoing Launch.

After 108 weeks of treatment, patients treated with sparsentan achieved a mean reduction in proteinuria from baseline of 50.0% compared to 32% for irbesartan.

FSGS partial remission of proteinuria endpoint was achieved by 38% versus 23% of patients, and complete remission was achieved by 18% and 7% of patients, respectively. 

A preliminary review of the safety results through 108 weeks of treatment indicates sparsentan has been generally well-tolerated and has a favorable safety profile.

William Blair writes that while the failure brings the likelihood of approval in FSGS into question, the totality of the data suggests that sparsentan has a therapeutic benefit in FSGS.

The analyst says there is still a chance of approval and is lowering the probability of success in the indication from 85% to 40%.

Price Action: TVTX shares are down 24.8% at $17.38 premarket on the last check Tuesday.