RESPONSE (study number CB8025-32048) is a Phase 3 clinical research study being conducted to learn more about the effectiveness and safety of seladelpar, a new investigational drug for the potential treatment of people with primary biliary cholangitis (PBC).

Data from previous studies in people with PBC provide preliminary evidence to support seladelpar’s utility in the treatment of PBC. These data have demonstrated that seladelpar has anti-cholestatic and anti-inflammatory effects and suggest that seladelpar may help treat people living with PBC.

The RESPONSE study is enrolling people who have been using ursodeoxycholic acid (UDCA or ursodiol), but have not achieved the recommended treatment goal or who develop troublesome side effects from UDCA that prevent them from continuing to take this treatment. In this study, we want to find out if seladelpar can improve PBC-related blood laboratory tests and can improve symptoms of PBC, such as itching.

The RESPONSE study will also ask participants who enter the study to consider a biopsy at baseline and end of study treatment. The biopsy is voluntary and performed only if it is considered safe by the study doctor. Participating in this aspect of the research study is important to help researchers and regulators better understand the changes in your liver health and the effect that seladelpar has on your liver health.

Who is eligible to participate in the RESPONSE study?

To qualify for this study you must:

  • Be 18 to 75 years old (inclusive)
  • Have been on a stable and recommended dose of UDCA for the past 12 months or have developed troublesome side effects from UDCA that required you to stop taking the medication
  • Be diagnosed with PBC 
  • Have blood laboratory test results in the following range:
    • Alkaline phosphatase (ALP) at least 1.67 times the upper limit of normal (ULN)
    • Bilirubin test levels less than two times the ULN

Doctors will check other requirements to confirm that you qualify for this study.

If you are currently taking UDCA, you will continue to take your UDCA at the same and recommended dose during study participation. During the study, you will be reimbursed for your UDCA for 12 months (the duration you are in the study). You will also begin to take seladelpar (study drug) or placebo, orally (by mouth) once a day for 52 weeks. At the end of the study, you may be given the opportunity to participate and receive seladelpar in the open label ASSURE long-term study (CB8025-31731).

There is no guarantee at this point in time, that being treated with seladelpar will have any effect on your PBC. There is also a 1 in 3 chance you will receive placebo in this study. Placebo is an inactive substance that looks like the investigational drug (seladelpar). During the study, neither you nor your doctor will know if you are receiving placebo or seladelpar.

Why should I participate in this study?

A clinical research study, or clinical study, is a planned set of tests conducted over time to learn about a new drug. The RESPONSE study is being conducted in order to learn more about the efficacy and safety of seladelpar, an investigational drug for the potential treatment of PBC.

If you qualify for and participate in this study, you may receive the following:

  • Seladelpar (study drug), or placebo, and UDCA (if applicable)
  • Study-related care from a physician with significant experience treating people with PBC
  • Study-related medical tests

All study medication and study-related care will be at no cost to you.

After participation in this study, you may be eligible to participate in the ASSURE long-term study (CB8025-31731) of seladelpar. Everyone in the long-term study will receive seladelpar at no cost for at least three years or until the development program is cancelled.

It is important to note that participating in this study will help to advance research related to the efficacy and safety of seladelpar. However, seladelpar may not have an effect on your PBC. Obeticholic acid (OCA or OCALIVA®) is an FDA/EMA approved treatment option for you. If you are not currently taking or aware of OCA, you should discuss your treatment options with your doctor.

What happens if I volunteer to participate in RESPONSE?

Your participation is your choice

Talk to your doctor and family to decide if this study is right for you.


For more Information:

If you wish to receive additional Information about seladelpar, the RESPONSE trial and other clinical studies please email