Travere Therapeutics has recently encountered setbacks in two critical trials involving their drug Filspari, with implications for its accelerated approval in treating IgA nephropathy (IgAN) and potential in addressing another renal condition.
The findings from these trials were presented at the American Society of Nephrology’s annual conference.
āAll the ways we looked at it, we see patients on [Filspari] preserving more of their kidney function over the study period versus a maximally titrated active comparator, which is great for patients.ā
– Jula Inrig, M.D., Travere’s Chief Medical Officer
The phase 3 PROTECT study assessed Filspari alongside the conventional treatment irbesartan in IgAN patients. Announced in September by Travere, the study did not achieve statistical significance for a secondary endpoint, the estimated glomerular filtration rate (eGFR), which was aimed at supporting Filspariās transition from FDA accelerated approval to full approval.
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Although Filspari users demonstrated a slight improvement in the eGFR slope compared to irbesartan, the difference did not meet statistical significance but fell within a clinically meaningful range, according to analysts from Leerink Partners.
In another endpoint crucial for Filspari’s approval in the EU, the drug did reach statistical significance based on data from week 6, exhibiting an advantage over irbesartan in the eGFR slope.
Inrig highlighted a specific two-year benefit of Filspari as particularly significant. The company’s analysis of a composite endpoint, which included various indicators of kidney failure, also reflected positively on Filspari’s performance.
Filspari’s accelerated approval for IgAN was granted in February, marking it as the first non-immunosuppressive agent to receive FDA backing, based on its efficacy in reducing proteinuria as shown in the PROTECT trial. Travere has stated it intends to seek full approval in the US. in the first half of 2024, but Inrig did not comment on the company’s discussions with the FDA to date.
Also Read: Filspari Fails To Confirm Kidney Benefit In IgAN, But Travere Hopes To Keep FDA Approval
Moreover, the drugās potential for treating focal segmental glomerulosclerosis (FSGS) is uncertain after the phase 3 DUPLEX trial did not meet its primary eGFR slope endpoints.
Inrig explained that there were several factors that might have affected the long-term eGFR outcomes in the trial. Nonetheless, Travere remains committed to exploring future possibilities for Filspari. “We will continue to figure out a path forward,” said Inrig.
