As reported on PR Newswire, the US Food and Drug Administration has granted Breakthrough Therapy designation to Kowa’s investigational therapy K-808 (pemafibrate) for primary biliary cholangitis (PBC), the company announced.
The designation is intended to speed development and regulatory review of therapies for serious illnesses when early evidence indicates they could offer a meaningful advantage over available options. Kowa said the FDA’s decision was supported by early findings from the ongoing phase 2 K-808-2.01 study.
Preliminary results, presented at the 2026 European Association for the Study of the Liver Congress, indicated that pemafibrate was associated with reductions in alkaline phosphatase (ALP), a laboratory marker commonly used to assess cholestatic liver disease activity and prognosis in PBC. These findings remain preliminary, and additional clinical data will be needed to establish the treatment’s effects on longer-term outcomes and patient symptoms.
Kowa is developing pemafibrate for adults with PBC who do not achieve an adequate response to ursodeoxycholic acid (UDCA), the standard first-line therapy. The company is pursuing use of the agent alongside UDCA in patients with an insufficient response, as well as a potential stand-alone option for individuals who cannot tolerate UDCA.
Pemafibrate is a selective peroxisome proliferator-activated receptor-alpha (PPARα) modulator. The drug is already marketed in Japan as Parmodia for hyperlipidemia, where it is used to improve lipid measures such as triglycerides. In PBC, Kowa is investigating whether PPARα activation may help address disease processes through effects on bile acid metabolism and inflammatory pathways.
PBC is a rare autoimmune disorder in which progressive damage to small bile ducts within the liver impairs bile flow. Over time, ongoing cholestasis and inflammation can lead to fibrosis, cirrhosis, and liver failure. The disease occurs predominantly in women and can cause substantial symptoms, including fatigue and severe itching.
Kowa plans to continue global development of K-808, including programs intended to support potential approvals in the United States and Japan.
