Irbesartan

The FDA has extended its decision date for an expansion of Travere's Filspari in FSGS by three months. The indication is a $2 billion opportunity in the U.S. alone, according to Leerink Partners. Much is riding on Travere Therapeutics’ bid to gain an expansion for Filspari to treat focal segmental glomerulosclerosis (FSGS). The indication represents a $2 billion peak sales opportunity in the U.S. alone, according to Leerink Partners.So it was with some trepidation that the San Diego rare disease specialist revealed that the FDA has postponed its decision on Filspari in FSGS by three months to April 13. Late last month—with a PDUFA date of Jan. 13 looming—the FDA presented Travere a series of information requests to clarify the clinical benefit of Filspari in FSGS, Travere CEO Eric Dube, Ph.D., said Monday at the J.P. Morgan Healthcare Conference, before the company announced the delay on Tuesday.None of the requests related to Filspari’s safety or manufacturing, Dube said.“As of Friday, just three days ago, we submitted responses to those questions that we believe should address the questions that they posed to us and those responses are currently under review,” Dube said Monday when asked about the FSGS decision. “Regulatory delays have become more commonplace over the last year,” Dube added. “While I can’t say that’s the case here, what I can say is that the agency has engaged in high level with us throughout this.”Since the company revealed the delay shortly after its JPM presentation, Travere’s shares have dropped by about 16.5%.Since 2020, there have been 80 FDA decisions on drug approvals that were extended for three months, according to analysts at Evercore ISI. Of these, 79% gained approval and 20% were rejected, with one withdrawal.“We think the stock is implying 50% odds of approval,” Evercore analysts wrote to clients this week.There have been mixed signals from the FDA since it accepted Travere’s application in May of last year and told the company that it planned to hold an advisory committee meeting to discuss the application. Four months later, the agency informed Travere that the adcomm was no longer needed. While cancelling plans for an advisory committee meeting appeared to be a positive sign for the company, it may have been more about the FDA’s sudden disinterest in conducting the panels under new leadership. The regulator has not held one to provide advice on a drug approval since August, according to an analysis from Jefferies. Even though a trial of Filspari in FSGS patients did not achieve its primary endpoint over 108 weeks of treatment, Filspari did provide “clinically meaningful benefit with significant proteinuria reduction, higher rates of partial and complete remission, and a lower rate of end-stage kidney disease compared to maximum labeled dose active control irbesartan,” Travere said in its release Tuesday.Filspari was originally approved on an accelerated basis in 2023 to treat patients with primary immunoglobulin A nephropathy (IgAN) who are at risk of rapid disease progression. It remains on the market despite a narrow miss in a confirmatory trial, gaining a full nod in September of 2024.  Sales are scaling up rapidly, from $132 million in 2024 to $322 million last year, with $103 million of that coming in the fourth quarter. Additionally, the company reported a record 908 new patient starts for Filspari in the fourth quarter.“As we move into 2026, we are focused on sustaining this momentum while preparing for a successful commercial launch of Filspari in FSGS, which, if approved, would be the first approved medication for these patients facing potential kidney failure,” Dube said in the company's Tuesday release.