We are a biopharmaceutical company focused on the development and commercialization of a late-stage pipeline of novel therapies for debilitating liver diseases. We focus on diseases for which the unmet medical need is high and the biology for treatment is clear. Our pipeline consists of two clinical-stage product candidates with mechanisms of action that have potential utility across a wide range of orphan liver diseases. We are initially developing maralixibat for the treatment of pediatric patients with progressive familial intrahepatic cholestasis, or PFIC, and Alagille syndrome, or ALGS. Based on improvements in pruritus, or itching, and other disease markers observed in Phase 2 clinical trials, we commenced enrollment in the Phase 3 MARCH clinical trial in PFIC in the second quarter of 2019 and are planning to initiate a Phase 3 clinical trial in ALGS in the first half of 2020. We are developing volixibat for the treatment of adult patients with cholestatic liver diseases and expect to initiate Phase 2 clinical trials in 2020. In addition to data from ongoing clinical trials of maralixibat, we expect to complete enrollment in the MARCH clinical trial in the second quarter of 2020 and announce topline Phase 3 data in late-2020 and clinical data for volixibat in 2022. Our mission is to develop life-changing therapies for patients suffering from debilitating liver diseases. Our management team has significant experience in liver and orphan diseases and progressing products from early stage research to clinical trials and ultimately to regulatory approval and commercialization. Michael Grey, our Executive Chairman and co-founder, was the Chief Executive Officer of Lumena Pharmaceuticals, Inc., or Lumena, where he led the development of maralixibat and volixibat prior to Lumena’s acquisition by Shire plc in June 2014. Christopher Peetz, our President and Chief Executive Officer and co-founder, as well as several other members of our management team, previously held leadership positions at Tobira Therapeutics, Inc., a liver disease company, prior to its acquisition by Allergan plc in November 2016. As part of our strategy to acquire and advance therapeutic candidates for debilitating liver diseases, we acquired maralixibat and volixibat in November 2018 from Shire plc and are continuing to advance these product candidates for rare cholestatic liver diseases with the assistance of key program leaders from Shire plc who joined us following the acquisition. We were incorporated in May 2018 as Mirum Pharmaceuticals, Inc., a Delaware corporation. Our principal executive offices are located at 950 Tower Lane, Suite 1050, Foster City, California 94404, and our telephone number is (650) 667-4085. Our website address is www.mirumpharma.com.
Use of proceeds:We estimate that we will receive net proceeds from this offering of approximately $67.3 million (or approximately $77.8 million if the underwriters’ option to purchase 750,000 additional shares of our common stock is exercised in full) based on the assumed initial public offering price of $15.00 per share, after deducting underwriting discounts and commissions and estimated offering expenses payable by us.A $1.00 increase (decrease) in the assumed initial public offering price of $15.00 per share would increase (decrease) the net proceeds to us from this offering by approximately $4.7 million, assuming the number of shares offered by us, as set forth on the cover page of this prospectus, remains the same, and after deducting underwriting discounts and commissions.Similarly, each increase (decrease) of 1.0 million shares in the number of shares of common stock offered by us would increase (decrease) the net proceeds to us from this offering by approximately $14.0 million, assuming the initial public offering price of $15.00 per share remains the same, and after deducting underwriting discounts and commissions.The principal purposes of this offering are to obtain additional capital to support our operations, to create a public market for our common stock and to facilitate our future access to the public equity markets.We anticipate that we will use the net proceeds of this offering, together with our existing cash and cash equivalents, as follows: • approximately $95.0 million to $105.0 million to further the clinical development of maralixibat, including our planned Phase 3 clinical trials in PFIC and ALGS and our anticipated clinical program in BA; • approximately $30.0 million to $40.0 million to further the clinical development of volixibat, including our planned Phase 2 clinical trials in ICP and PSC; and • the remainder for other ongoing research and development activities, and for general corporate purposes, including working capital, operating expenses and capital expenditures.We may also use a portion of the remaining net proceeds and our existing cash and cash equivalents to in-license, acquire, or invest in complementary businesses, technologies, products or assets.However, we have no current commitments or obligations to do so.We believe, based on our current operating plan, that the net proceeds from this offering, together with our existing cash and cash equivalents, will be sufficient to fund our operations for at least the next 12 months.In particular, we expect that the net proceeds from this offering will allow us to complete our planned Phase 3 clinical trials for maralixibat and our planned Phase 2 clinical trials for volixibat.However, our expected use of proceeds from this offering described above represents our current intentions based on our present plans and business condition.As of the date of this prospectus, we cannot predict with certainty all of the particular uses for the proceeds to be received upon the closing of this offering or the actual amounts that we will spend on the uses set forth above.The net proceeds from this offering, together with our cash and cash equivalents, will not be sufficient for us to fund all of our product candidates through regulatory approval, and we will need to raise additional capital to complete the development and commercialization of all of our product candidates.The amounts and timing of our actual expenditures will depend on numerous factors, including the time and cost necessary to conduct our planned clinical trials, the results of our planned clinical trials and other factors described in this prospectus, as well as the amount of cash used in our operations and any unforeseen cash needs.Therefore, our actual expenditures may differ materially from the estimates described above.We may find it necessary or advisable to use the net proceeds for other purposes, and we will have broad discretion in the application of the net proceeds.We will have broad discretion over how to use the net proceeds to us from this offering.We intend to invest the net proceeds to us from the offering that are not used as described above in short-term, investment-grade, interest-bearing instruments.
Competition:There are no FDA-approved therapies for the treatment of ALGS, PFIC, PSC or ICP in the United States.Symptomatic treatment with antipruritics, such as cholestyramine, typically provides only modest relief.Bristol Myers Squibb Company has discontinued its brand name cholestyramine, but generic versions of the drug are marketed by Upsher-Smith Laboratories, Inc., Par Pharmaceutical Companies, Inc. and Sandoz Inc., the generic pharmaceuticals division of Novartis AG.UDCA is marketed by a number of generic pharmaceutical companies such as Mylan Inc., Actavis Inc., Lannett Company, Inc. and Par Pharmaceutical Companies, Inc.A number of drugs, including UDCA, rifampin and naltrexone, are used off-label to treat patients suffering from cholestatic liver diseases.Additionally, surgical interventions, such as partial external biliary diversion and nasobiliary drainage, and extracorporeal liver support, such as Molecular Adsorbent Recirculation System, are also employed in an attempt to lower bile acid levels, manage pruritus and improve measures of liver function.We are aware of two other companies pursuing clinical development of therapies that reduce sBA levels via the ASBT pathway.GlaxoSmithKline plc and Albireo Pharma, Inc., or Albireo, have ASBT inhibitors in clinical development for cholestatic liver diseases.We are aware that Albireo is enrolling a Phase 3 trial for PFIC1 and PFIC2 patients for A4250, or odevixibat, and has announced plans to pursue development in BA and other cholestatic liver diseases.Albireo has announced plans to release PFIC Phase 3 topline data in late-2019 or early-2020 and to initiate a clinical trial of A4250 in BA in the second half of 2019.We are aware that GlaxoSmithKline plc is conducting a Phase 2 trial of its ASBTi in PBC patients.We are also aware that Intercept Pharmaceuticals, Inc. is exploring BA as an indication for obeticholic acid.Further, we may compete with companies that are developing gene therapy for the treatment of PFIC.In adult settings of cholestasis, similar to pediatric settings, cholestyramine, UDCA, rifampin and naltrexone are commonly used agents.We are not aware of FDA approved therapeutics for the treatment of PSC or ICP.We are aware of several agents in clinical development for the treatment of PSC, including Allergan plc’s cenicriviroc, CymaBay Therapeutics, Inc.’s seladelpar, DURECT Corporation’s DUR928, Gilead Sciences, Inc.’s GS-9674, HighTide Therapeutics Inc.’s HTD1801, Intercept Pharmaceuticals, Inc.’s Ocaliva, or obeticholic acid and NGM Biopharmaceuticals, Inc.’s NGM282.Furthermore, one of our own product candidates may be used off-label in the market for another of our product candidates, adversely affecting the sales of that product candidate.