Chris Peetz
Analyst · SVB Leerink. Please go ahead with your question
Great, thanks, Ian. Mirum is focused on advancing life-changing medicines for rare liver diseases. Today, we'll provide updates and context around some of the exciting recent steps we've taken in Building Mirum as the leading rare liver disease company. It's an important time in realizing our vision. I'll cover our regulatory and pipeline updates, followed by Peter on global commercialization and then Ian with the financial update. First, recapping recent announcements. Our first potential launch is around the corner for maralixibat for Alagille syndrome in the U.S. with the PDUFA date in the third quarter. We strengthened our IP position with the patent allowance in the U.S. that extends exclusivity for maralixibat to 2040. We've broadened our pipeline to include late-stage programs in six indications in the gene therapy collaboration for PFIC. And entered into a partnership for maralixibat in Greater China to accelerate the global launch of maralixibat. Today, we'll talk about these updates and the value we continue to build within Mirum's programs. With that in, maralixibat has great momentum and is on the cusp of launch, if approved by the FDA. In March, our NDA was accepted for priority review by the FDA with the PDUFA date of September 29. We are planning to be launch-ready by late summer. The FDA also indicated that at this time, there are no plans for an advisory committee. From our standpoint, our regulatory review progress is on track, and we've been able to accommodate all inspections to date. If maralixibat is approved in the U.S., it would serve as the first treatment approved for patients with Alagille syndrome. Peter will share more with you about our launch readiness and the unveiling of our patient services program, Mirum Access Plus. We are optimistic about the benefit maralixibat can have for patients with Alagille syndrome. In the ICONIC study, which serves as our pivotal study, highly significant improvements in pruritus were observed, with more than 80% of patients achieving a clinically meaningful reduction in its score. We have six years of follow-up data and are seeing durable responses across all three randomized studies of maralixibat and Alagille syndrome, a program that included 86 patients in total. Now we are analyzing the impact of maralixibat on event-free survival across these studies, looking at time to biliary diversion surgery, liver transplant, hepatic decompensation events or death. These data and natural history comparisons are planned to be part of our European filing for Allagille syndrome, anticipated next year as an indication expansion to the PFIC2 application. Our PFIC2 application in Europe has been validated. We are working through the review process and track with our plans to launch maralixibat for PFIC2 in Europe in early 2022, should it be approved. As a reminder, this filing is based on key findings from the Indigo Phase II study. First, serum bile acid response leading to improvement in itch, growth and other liver parameters. That is followed by improvements in transplant-free survival in those serum bile acid responders. And third, our filing includes comparisons to a natural history cohort on event-free survival. Turning to our Phase III MARCH-PFIC study, the study is advancing well with approximately 50 patients with PFIC subtypes 1, 2, 3 and 4 randomized across two cohorts. Some countries continue to be impacted by COVID-19 and competitive enrollment, so we now plan to extend enrollment in order to achieve the target number of patients per cohort. This study is projected to be the largest randomized study ever conducted in PFIC, and includes a broad range of genetic subtypes. As a reminder, MARCH-PFIC evaluates a higher dose of maralixibat that has been shown to drive greater bile acid clearing activity. And importantly, we remain on track to report top line results in early 2022. And further strengthening our position in PFIC, we recently announced an exciting new gene therapy collaboration with the vet therapeutics, a leader in liver-directed gene therapy. While achieving incredible clinical results with maralixibat, including improvements in five-year transplant-free survival, we have recognized that there will be PFIC patients with genetic subtypes who will not respond to ASBT inhibition. This was the impetus for entering into the optional license agreement with Vivet for their two PFIC gene therapy programs. Our vision is that maralixibat will be first-line treatment in PFIC. And VTX-803 and VTX-802 will be second line treatment options for PFIC3 and PFIC3 and those patients who do not respond to ASBT inhibition. These programs work by addressing the root cause of the disease through correction of the defective genes that cause each condition. This is cutting-edge technology. And while early, it's our hope that these gene therapies could someday offer a cure for patients living with PFIC3 and PFIC2. In the collaboration, Vivet's experience gene therapy team will lead work until IND submission and Mirum will lead the clinical development and commercialization globally. We look forward to sharing more with you as these studies progress. Of note, Vivet has two abstracts at the upcoming American Society for gene and cell therapy on additional VTX-803 studies showing further preclinical proof-of-concept. Now shifting back to our clinical development programs underway. We were pleased to expand the maralixibat program with the initiation of the Phase IIb EMBARK study in Biliary Atresia. And we also significantly expanded our clinical programs for volixibat. We believe this is another potentially transformative treatment for several cholestatic liver diseases. Earlier this year, we launched our Phase IIb VISTAS study for adults with primary sclerosing cholangitis. And more recently, we launched the Phase IIb OHANA study that will evaluate volixibat in intrahepatic cholestasis of pregnancy. And finally, a Phase IIb study in primary biliary cholangitis is targeted for later this year. We've incorporated FDA feedback into the design of all of these studies, all of which we believe are potentially registrational. We expect interim analysis for the VISTAS and OHANA studies to occur in 2022. So the growing body of evidence of maralixibat, volixibat strengthens the least and their potential transformative impact on the lives of patients with cholestatic liver diseases and their families. On that note, I will now turn it over to Peter, who will provide an overview of our launch readiness activities and partnership update. Peter?