Albireo Pharma, Inc. announced the acceptance of two late breakers, including one late breaker with new data from the Phase 3 ASSERT study, to be presented as an oral presentation at the American Association for the Study of Liver Disease (AASLD) The Liver Meeting® 2022, November 4 – 8, 2022. Positive topline results from ASSERT, a global, double-blind, randomized, placebo-controlled trial which evaluated the safety and efficacy of Bylvay in ALGS patients from birth to early adulthood, were announced in October. A second late breaker was also accepted as an oral presentation with data showing Bylvay restored biliary bile acid secretion in treatment-responsive progressive familial intrahepatic cholestasis (PFIC) patients with bile salt export pump (BSEP) deficiency in the PEDFIC 1 trial.

A third oral presentation was previously announced, with a pooled data analysis of the PEDFIC trials showing that a decrease in serum bile acids was strongly associated with native liver survival in PFIC patients treated with Bylvay. Oral Presentation (Abstract #5005; Publication #38786): Efficacy and Safety of Odevixibat in Patients with Alagille Syndrome: Top-line Results from ASSERT, a Phase 3, Double-Blind, Randomized, Placebo-Controlled Study; Presenter: Dr. Nadia Ovchinsky, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, USA; Session Title: Late-Breaking Oral Abstract Session 1; Presentation Type: Oral, Late-Breaking Parallel Session; Date & Time: November 7, 2022, 9:00 AM - 10:30 AM EST; Presentation Time: 9:15 AM EST. Oral Presentation (Abstract #5004; Publication #38801): Odevixibat Treatment in Responsive Patients with Bile Salt Export Pump Deficiency Restores Biliary Bile Acid Secretion, as Indicated by Serum Bile Acid Composition; Presenter: Dr. Mark Nomden, Department of Surgery and Pediatrics, University Medical Center Groningen, Groningen, the Netherlands; Session Title: Late-Breaking Oral Abstract Session 1; Presentation Type: Oral, Late-Breaking Parallel Session; Date & Time: November 7, 2022, 9:00 AM - 10:30 AM EST; Presentation Time: 10:00 AM EST; Oral Presentation (Abstract #865): Native Liver Survival in Odevixibat Serum Bile Acid Responders: Data from the PEDFIC Studies in Patients with Progressive Familial Intrahepatic Cholestasis; Presenter: Dr. Richard J. Thompson, Institute of Liver Studies, King's College London Session Title: Genes to Cures: What's New in Pediatric Liver Disease; Date & Time: November 6, 2:10 PM EST ASSERT Phase 3 Clinical Trial Data: ASSERT is a gold standard, prospective intervention trial with 32 sites across North America, Europe, Middle East, and Asia Pacific.

The double-blind, randomized, placebo-controlled trial was designed to evaluate the safety and efficacy of 120 µg /kg/day Bylvay (odevixibat) for 24 weeks in relieving pruritus in patients with Alagille syndrome (ALGS). Key secondary endpoints measure serum bile acid levels and safety and tolerability. The trial enrolled patients aged 0 to 17 years of age with a genetically confirmed diagnosis of ALGS.

The primary efficacy endpoint was a change from baseline to month 6 (weeks 21 to 24) in pruritus measured by scratching with the PRUCISION Observer-Reported Outcome (ObsRO) scratching score caregiver instrument (0-4 point scale). The key secondary efficacy endpoint was a change in serum bile acid responses (sBAs) from baseline to the average of weeks 20 and 24. In the primary analysis, the study met the primary endpoint showing statistically significant reduction in pruritus as measured by the PRUCISION Observer-Reported Outcome scratching score (0-4 point scale), from baseline at month 6 (weeks 21 to 24), compared to the placebo arm (p=0.002).

The study also met the key secondary endpoint showing a statistically significant reduction in serum bile acid concentration from baseline to the average of weeks 20 and 24 (compared to the placebo arm p=0.001). Statistically significant improvements in multiple sleep parameters were observed as early as week 1-4 compared to patients on placebo with continued improvement through week 24. In the study, there were no patient discontinuations.

Bylvay was well tolerated, with an overall adverse event incidence similar to placebo and a low incidence of drug-related diarrhea (11.4% vs. 5.9% placebo). The Company continues to enroll patients in the Phase 3 BOLD study, which is the first and only pivotal trial of an IBATi in biliary atresia (BA) and remains on track to fully enroll by end of year, with topline data planned for 2024.

BA is the most common pediatric cholestatic liver disease with no approved drug treatment. With clinical programs in ALGS and BA, Bylvay has the potential to be approved for three pediatric cholestatic liver diseases.