New Phase 3 Data at WCPGHAN Show Long-Term Safety, Tolerability, and Treatment Benefits of Bylvay™ (odevixibat) in PFIC

– Data being presented show long-term benefits of Bylvay in children with PFIC – – First potential non-invasive treatment option that could transform the treatment paradigm – – Observed long-term improvements in total bilirubin, growth, and sleep measures – – Data validates the PRUCISION© ObsRO pruritus measurement tool and proves reliability – BOSTON, June 03, 2021 (GLOBE NEWSWIRE) — Albireo Pharma, Inc. (Nasdaq: ALBO), a clinical-stage rare liver disease company developing novel bile acid modulators, today presented clinical data from its Phase 3 PEDFIC 1 study and an interim data cut of the PEDFIC 2 long-term extension study of its lead product candidate, Bylvay (odevixibat). Data being shared at the 6th World Congress of Pediatric Gastroenterology, Hepatology, and Nutrition (WCPGHAN) Meeting on June 2 – 5 shows that long-term treatment (up to 48 weeks) was associated with clinically meaningful, positive effects on cholestasis, growth, and sleep parameters in patients with progressive familial intrahepatic cholestasis (PFIC). The totality of the data supports the potential of Bylvay to provide benefits to patients with PFIC. Bylvay is a potent, once-daily, non-systemic ileal bile acid transport inhibitor (IBATi) currently being developed for the treatment of PFIC, biliary atresia, and Alagille syndrome. “The data being presented at WCPGHAN showed consistent long-term safety and tolerability across studies, treatment groups, and doses and long-term treatment benefits of Bylvay in children with PFIC,” said Ron Cooper, President and Chief Executive Officer of Albireo. “These results not only give us confidence in the potential for Bylvay in patients with PFIC, but also in our global pivotal studies in biliary atresia and Alagille syndrome.” Long-Term Safety and TolerabilityPEDFIC 1 was the first and largest, global, pivotal Phase 3 study conducted in PFIC, which evaluated the efficacy and tolerability of Bylvay in reducing pruritus and serum bile acids in a randomized, double-blind, placebo-controlled trial, and PEDFIC 2 is a long-term, open-label Phase 3 extension study. Bylvay improved pruritus, cholestasis, and growth with durable effect. The data being presented confirms the safety and tolerability of Bylvay in children with PFIC. The observed safety and tolerability profile of Bylvay was consistent across studies, treatment groups, and doses. The analyses discussed in this oral presentation include data for of the safety and tolerability of Bylvay in children with PFIC treated in both PEDFIC 1 and PEDFIC 2 treated for up to 48 weeks. No drug-related serious adverse events were reported in either PEDFIC 1 or PEDFIC 2. One patient in PEDFIC 1 and 3 patients in PEDFIC 2 treated with Bylvay withdrew due to an adverse event. There were low numbers of gastrointestinal adverse events; specifically, treatment-related diarrhea/frequent bowel movements was reported in 10% of Bylvay treated patients in PEDFIC 1 and 5% of placebo-treated patients. Long-Term Benefits of BylvayThe oral presentation shows data for secondary and exploratory efficacy outcomes from the PEDFIC 1 and PEDFIC 2 studies, including growth, hepatic chemistries, and sleep parameters. The PEDFIC 2 study observed two cohorts: Cohort 1 consists of PFIC1 and PFIC2 patients from PEDFIC 1 who rolled into PEDFIC 2. This includes patients treated with Bylvay, as well as patients treated with placebo. Cohort 2 consists of newly enrolled patients who did not participate in the PEDFIC 1 trial, including patients with PFIC1, PFIC2, PFIC3 and MYO5B deficiency. At the PEDFIC 2 interim data cut, median duration of exposure to Bylvay was 43 weeks in patients treated with Bylvay, 36 weeks for cohort 1 patients previously treated with placebo in PEDFIC 1, and 19 weeks in cohort 2. Long-term treatment with Bylvay was associated with clinically meaningful, positive effects on cholestasis, growth, and sleep parameters in patients with PFIC. The totality of the data support the potential of Bylvay to provide benefits to patients with PFIC. Key findings include: Significant improvement in height and weight: Mean height Z scores in the patient group treated with Bylvay increased significantly from –1.6 to –0.5 (P=0.02) with 48 weeks of treatment; similarly, those in the treatment naive group experienced increases in height Z score with 24 weeks of Bylvay. Changes in weight mirrored those observed with height (e.g., weight Z scores in patients treated with Bylvay normalized over 48 weeks [P=0.02; P=0.03]).Significant decreases in total bilirubin and serum ALT: In addition to the previously reported decreases in pruritus and serum bile acids in PEDFIC 1 and PEDFIC 2, Bylvay also decreased total bilirubin levels by 20 – 25 µmol/L, further indicating an improvement of cholestasis.Reductions in the percentage of days needing help to fall asleep, needing soothing, and sleeping with caregiver: From weeks 24–48 with Bylvay (both groups), there were reductions in the percentage of days needing help to fall asleep (P<0.0001 vs P=0.005, respectively), needing soothing (P<0.0001 vs P=0.12), and sleeping with caregiver (P=0.001 vs P=0.15). The long-term data from the PEDFIC 2 study collectively reaffirm Bylvay’s potential to be the first drug treatment approved for patients living with PFIC, a devastating disease which is currently treated with surgical options including liver transplantation. The abstracts will also be published as an abstract book in the Journal of Pediatric Gastroenterology and Nutrition (JPGN). Validation of the PRUCISION Caregiver-Reported (ObsRO) Pruritus MeasureThe PRUCISION observer-reported (ObsRO) pruritus measurement tool, which was developed to adequately measure pruritus in pediatric patients, was used in the Phase 3 PEDFIC 1 and PEDFIC 2 studies. The data shows that the PRUCISION ObsRO pruritus measure is reliable, valid, and sensitive to change, and as such, is appropriate for evaluating the effect of treatment on pruritus in PFIC and potentially in other pediatric CLDs. A clinically meaningful ObsRO score change threshold of −1.00 was established. The PRUCISION ObsRO pruritus measurement tool is also being used to assess the primary endpoint in the ongoing phase 3 ASSERT trial for children with Alagille syndrome. About Bylvay (odevixibat)Bylvay is an investigational product candidate being developed to treat rare pediatric cholestatic liver diseases, including PFIC, biliary atresia and ALGS. A potent, once-daily, non-systemic ileal bile acid transport inhibitor (IBATi), Bylvay acts locally in the small intestine. Bylvay does not require refrigeration and can be taken as a capsule for older children, or opened and sprinkled onto food, which are factors of key importance for adherence in a pediatric patient population. The FDA has granted Priority Review and set a PDUFA goal date of July 20, 2021. In Europe, the EMA validated MAA. Bylvay is the only IBATi granted accelerated assessment by the EMA. Bylvay also been granted Orphan Designation, as well as access to the PRIority MEdicines (PRIME) scheme for the treatment of PFIC. The EMA’s Pediatric Committee has agreed to Albireo’s Bylvay Pediatric Investigation Plans for PFIC and biliary atresia. In addition to PFIC, Bylvay has Orphan Drug Designations for the treatment of Alagille syndrome, biliary atresia and primary biliary cholangitis. With FDA and EMA regulatory submissions complete, Bylvay has the potential to become the first approved drug treatment for patients with PFIC in the U.S. and Europe. The Company anticipates potential regulatory approvals, issuance of a rare pediatric disease priority review voucher and launch in the second half of 2021. The MAA and NDA filings are supported by results from PEDFIC 1 and PEDFIC 2 Phase 3 studies. PEDFIC 1 was the first and largest, global, pivotal Phase 3 study conducted in PFIC, which evaluated the efficacy and tolerability of Bylvay in reducing pruritus and serum bile acids in a randomized, double-blind, placebo-controlled trial. In the PEDFIC 1 study, Bylvay met both primary endpoints and was well tolerated with very low incidence of diarrhea/frequent bowel movements (9.5% of Bylvay treated patients vs. 5.0% of placebo patients). ir.albireopharma.com/news-releases/news-release-details/albireo-phase-3-trial-meets-both-primary-endpoints-odevixibat. PEDFIC 2 is a long-term, open-label Phase 3 extension study. The Company also provides an Expanded Access Program (EAP) for eligible patients with PFIC in the U.S., Europe, Canada and Australia. Bylvay is also currently being evaluated in the BOLD Phase 3 trial in patients with biliary atresia, and the global Phase 3 ASSERT trial for ALGS. About AlbireoAlbireo Pharma is a clinical-stage biopharmaceutical company focused on the development of novel bile acid modulators to treat rare pediatric and adult liver diseases. Albireo’s lead product candidate, Bylvay, is being developed to treat rare pediatric cholestatic liver diseases with Phase 3 trials in PFIC, Alagille syndrome and biliary atresia. For PFIC, the FDA recently granted Priority Review and set a PDUFA goal date of July 20, 2021. In Europe, the EMA validated MAA. Bylvay is the only IBATi granted accelerated assessment by the EMA. Bylvay has been provisionally accepted by both the FDA and EMA as the brand name for odevixibat. The Company has also initiated a Phase 1 clinical trial for A3907 to advance development in adult cholestatic liver disease, with IND-enabling studies moving ahead with A2342 for viral and cholestatic liver disease. Albireo was spun out from AstraZeneca in 2008 and is headquartered in Boston, Massachusetts, with its key operating subsidiary in Gothenburg, Sweden. The Boston Business Journal named Albireo one of the 2020 Best Places to Work in Massachusetts for the second consecutive year. For more information on Albireo, please visit www.albireopharma.com. Forward-Looking Statements This press release includes “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements include statements, other than statements of historical fact, regarding, among other things: the plans for, or progress, scope, cost, initiation, duration, enrollment, results or timing for availability of results of, development of Bylvay or any other Albireo product candidate or program; expectations regarding the impact of the COVID-19 pandemic on our business and our ability to adapt our plans and activities as appropriate; the pivotal trial for Bylvay in biliary atresia (BOLD), and the pivotal trial for Bylvay in Alagille syndrome (ASSERT); the target indication(s) for development or approval, the size, design, population, location, conduct, cost, objective, enrollment, duration or endpoints of any clinical trial, or the timing for initiation or completion of or availability or reporting of results from any clinical trial, including the long-term open-label extension study for Bylvay in PFIC, BOLD, ASSERT and the Phase 1 clinical trial for A3907; the potential approval and commercialization of Bylvay and the timing for such potential approval and commercialization; the potential for Bylvay to become the first approved drug for PFIC patients; discussions with the FDA or EMA regarding our programs; the potential benefits or competitive position of Bylvay or any other Albireo product candidate or program or the commercial opportunity in any target indication; the potential effects of Bylvay of the treatment of PFIC patients and its potential to improve the current standard of care; the potential benefits of an orphan drug designation; the potential issuance of a rare pediatric disease priority review voucher; or Albireo’s plans, expectations or future operations, financial position, revenues, costs or expenses. Albireo often uses words such as “anticipates,” “believes,” “plans,” “expects,” “projects,” “future,” “intends,” “may,” “will,” “should,” “could,” “estimates,” “predicts,” “potential,” “planned,” “continue,” “guidance,” or the negative of these terms or other similar expressions to identify forward-looking statements. Actual results, performance or experience may differ materially from those expressed or implied by any forward-looking statement as a result of various risks, uncertainties and other factors, including, but not limited to: whether the NDA for Bylvay for the treatment of pruritus in patients with PFIC will be approved by the FDA and whether the MAA for Bylvay in PFIC will be approved by the EMA; whether the FDA or EMA will complete their respective reviews within the target timelines, including the FDA’s PDUFA goal date, as a potential result of the impact of the COVID-19 pandemic or otherwise; the risk that the NDA will not be approved despite the FDA’s acceptance of the NDA for review or that the MAA will not be approved despite CHMP’s opinion recommending approval of Bylvay for the treatment of PFIC; whether the FDA or EMA will require additional information, whether we will be able to provide in a timely manner any additional information that the FDA or EMA requests, and whether such additional information will be satisfactory to the FDA and EMA; other potential negative impacts of the COVID-19 pandemic, including on manufacturing, supply, conduct or initiation of clinical trials, or other aspects of our business; whether favorable findings from clinical trials of Bylvay to date, including findings in indications other than PFIC, will be predictive of results from other clinical trials of Bylvay; whether either or both of the FDA and EMA will determine that the primary endpoint for their respective evaluations and treatment duration of the double-blind Phase 3 trial in patients with PFIC are sufficient to support approval of Bylvay in the United States or the European Union, to treat PFIC, a symptom of PFIC, a specific PFIC subtype(s) or otherwise; the outcome and interpretation by regulatory authorities of the ongoing third-party study pooling and analyzing of long-term PFIC patient data; the timing for initiation or completion of, or for availability of data from, clinical trials of Bylvay or A3907, including BOLD and ASSERT, and the outcomes of such trials; Albireo’s ability to obtain coverage, pricing or reimbursement for approved products in the United States or European Union; delays or other challenges in the recruitment of patients for, or the conduct of, company’s clinical trials; and Albireo’s critical accounting policies. These and other risks and uncertainties that Albireo faces are described in greater detail under the heading “Risk Factors” in Albireo’s most recent Annual Report on Form 10-K or in subsequent filings that it makes with the Securities and Exchange Commission. As a result of risks and uncertainties that Albireo faces, the results or events indicated by any forward-looking statement may not occur. Albireo cautions you not to place undue reliance on any forward-looking statement. In addition, any forward-looking statement in this press release represents Albireo’s views only as of the date of this press release and should not be relied upon as representing its views as of any subsequent date. Albireo disclaims any obligation to update any forward-looking statement except as required by applicable law. Media Contact:Colleen Alabiso, 857-356-3905, [email protected] Rivero, 617-947-0899, [email protected] Investor Contact:Hans Vitzthum, LifeSci Advisors, LLC., 617-430-7578