Tricida sinks as FDA rejection raises prospect of new trial

The FDA has rejected Tricida’s filing for approval of a treatment for metabolic acidosis in patients with chronic kidney disease. Tricida said it may need to run another clinical trial to fix the deficiencies that led the FDA to issue the complete response letter.

Veverimer, also known as TRC101, is designed to attach to hydrochloric acid in the gastrointestinal tract and keep it bound until it is excreted. In doing so, veverimer could cut acid levels in the body and increase serum bicarbonate. The mechanism led Tricida to identify veverimer as a way to reverse the acid accumulation that causes complications in a significant minority of advanced chronic kidney disease patients. 

San Francisco-based Tricida filed for accelerated approval of veverimer on the basis of a 12-week phase 3 trial and an associated 40-week extension. The placebo-controlled phase 3, which enrolled patients at sites in the U.S. and Eastern Europe, linked veverimer to a significant change in serum bicarbonate. 

Tricida saw the data as strong enough to support approval in the U.S. The FDA took a very different view of the evidence, as Tricida explained in a statement to disclose the setback.

“According to the CRL, the FDA is seeking additional data beyond the TRCA-301 and TRCA-301E trials regarding the magnitude and durability of the treatment effect of veverimer on the surrogate marker of serum bicarbonate and the applicability of the treatment effect to the U.S. population. FDA also expressed concern as to whether the demonstrated effect size would be reasonably likely to predict clinical benefit,” Tricida said.

It is unclear exactly what that means for Tricida and veverimer. Tricida said the response letter covers multiple options for resolving the deficiencies. An additional clinical trial may be necessary, Tricida said. That would add to Tricida’s costs and delay the approval of veverimer. Tricida plans to meet with the FDA to discuss the next steps in the fourth quarter. 

Tricida braced investors for a potential rejection last month when it disclosed the FDA had “identified deficiencies that preclude discussion of labeling and postmarketing requirements/commitments.” At that time, shares in Tricida fell by almost 40%. Tricida’s share price slipped further still over the next few weeks.

This week, Tricida’s stock tumbled another 24%. With Tricida forewarning investors about the likely FDA rejection, the decline may reflect details of the deficiencies disclosed this week and the prospect of Tricida needing to pay for another trial to address them. Tricida had $437 million at the last count and calculates it can fund its operation into early 2022. 

The complete response letter is the latest in a flurry of rejections by the FDA, which has also knocked back filings for approval of Gilead’s rheumatoid arthritis prospect filgotinib and BioMarin’s Roctavian gene therapy in recent weeks.