CymaBay maps out regulatory filing for primary biliary cholangitis drug seladelpar

CymaBay Therapeutics could file for a regulatory approval of its primary biliary cholangitis drug seladelpar with the US Food and Drug Administration (FDA) early next year, said CEO Sujal Shah in an interview with Pharmaceutical Technology.

While the company has not stated specific public guidance on the timing of the filing, such paperwork can take between four to six months, explained Shah. Due to this, early next year is a reasonable expectation for when the approval application will be done, the CEO added. The company will first file in the US before following up with applications in the EU and the UK, said Shah.

On 21 September, CymaBay announced the start of the Phase IIIb/IV AFFIRM confirmatory trial with seladelpar. The aforementioned regulatory filing efforts follow the release of positive topline data from the Phase III RESPONSE trial (NCT04620733) earlier this month. In that trial, 61.7% of patients dosed with 10mg of seladelpar met the primary composite endpoint related to serum alkaline phosphatase and bilirubin levels, compared to only 20% of patients in the placebo cohort, after 12 months, per the 7 September press release.

Since the company plans to pursue the subpart H accelerated approval pathway for seladelpar, which uses surrogate measures likely to predict outcomes, it also needs to run an outcome study, explained Shah. The study announced earlier today will address this need.

Building on the RESPONSE results, the company is also working on its Phase III ASSURE study (NCT03301506) which is aimed at collecting long-term safety data on seladelpar in primary biliary cholangitis. In August, the US-based company started the Phase III IDEAL trial, which examines the use of seladelpar in primary biliary cholangitis patients with incomplete control of alkaline phosphatase. According to Shah, the company will focus on enrolling subjects for this trial through the rest of the year and early next year.

Primary biliary cholangitis is a liver disease where one’s immune system attacks the bile ducts, which leads to bile build up in the organ. The condition can result in liver failure if untreated. The condition is usually first treated with ursodeoxycholic acid. In May 2016, the FDA approved Intercept’s Ocaliva (obeticholic acid) for use in primary biliary cholangitis in combination with ursodeoxycholic acid in adults with an inadequate response to the first-line therapy and as a single therapy for those who cannot tolerate ursodeoxycholic acid.

Seladelpar is an oral peroxisome proliferator-activated receptor delta agonist. While ursodeoxyocholic acid does not reduce itch, and Ocaliva can reportedly increase the incidence of itching, seladelpar reduces it, said Shah. This also is one of the key differentiators for the drug, he explained.

Beyond seladelpar, CymaBay is mulling the next steps for its second asset MBX-2982. The company expects to share top-line results from a Phase IIa trial for the prevention of hypoglycemia in patients with type 1 diabetes by the end of the year, said Shah. CymaBay may consider licensing the drug to a company more focused on diabetes if the data is compelling or run a potential Phase IIb trial as a further option, said Shah.