-- Oral treatment with novel dual-mechanism of action has the potential to address the two critical elements of COVID-19: viral replication and uncontrolled inflammatory response -- -- Randomized, double-blind, placebo-controlled, Phase 2/3 clinical study with two stages initiated at several sites in Australia -- -- Also enrolling patients in the US, Spain and Brazil -- PTC Therapeutics, Inc., today announced the initiation of a Phase 2/3 trial called FITE19 to investigate PTC299, a dihydroorotate dehydrogenase (DHODH) inhibitor, as a potential treatment for COVID-19. PTC299 is an oral investigational drug with a novel dual-mechanism of action that has the potential to address the two critical elements of COVID-19: 1) the high viral replication and 2) the uncontrolled inflammatory response that ensues after infection. Study sites are enrolling patients at Monash Health, Sunshine Hospital and Westmead. "As we continue to feel the overwhelming and devastating effects of COVID-19 globally, we are hopeful for the potential of PTC299 to be part of the solution," said Nikhil Jayaram, Regional Head Australasia, PTC Therapeutics, Inc. "Initiating a clinical trial in Australia allows us to further investigate the unique ways in which PTC299 can combat COVID-19, by reducing the high viral replication and also selectively attenuating the immune response caused by the uncontrolled cytokine storm resulting from the infection." PTC299 is an oral, small molecule tablet that inhibits the cellular enzyme DHODH which is used to produce the RNA building blocks for the production of SARS-CoV-2. PTC299 has demonstrated potent inhibition of viral replication in SARS-CoV-2 cell-based assays, which has led to PTC moving rapidly into the clinic. A number of RNA viruses require the same building blocks, which explains why in preclinical tests PTC299 has also shown broad-spectrum antiviral activity. If you are interested in participating in the study, please visit PTC clinical trials ( https://c212.net/c/link/?t=0&l=en&o=2982065-1&h=1069700334&u=https%3A%2F%2Fclinicaltrials.ptcbio.com%2Fen%2Ftrial-details%2F%3Fid%3DPTC299-VIR-015-COV19&a=PTC+clinical+trials ). The primary objective of the trial is to evaluate the clinical efficacy of PTC299 compared with placebo assessed by time to respiratory improvement in adults hospitalized with COVID-19. PTC also has sites that are actively recruiting in the U.S., Brazil and Spain as part of the trial. About PTC299 PTC299 is an investigational oral small molecule that inhibits the cellular enzyme dihydroorotate dehydrogenase (DHODH). Recently, DHODH has been independently identified as one of the top-three most promising targets for intervention in COVID-19. PTC299 is being evaluated for the potential treatment of patients with COVID-19. With a novel dual-mechanism of action, PTC299 inhibits DHODH activity which leads to a reduction of pyrimidine biosynthesis and SARS-CoV-2 viral replication, and selectively modulates the immune response by attenuating the stress-induced inflammatory cytokine storm. PTC299 has broad-spectrum antiviral activity and potent inhibition of numerous RNA viruses with low nanomolar potency. PTC299 is also currently being evaluated in an ongoing clinical study in acute myeloid leukemia (AML). About PTC Therapeutics, Inc. PTC is a science-driven, global biopharmaceutical company focused on the discovery, development and commercialization of clinically differentiated medicines that provide benefits to patients with rare disorders. PTC's ability to globally commercialize products is the foundation that drives investment in a robust and diversified pipeline of transformative medicines and our mission to provide access to best-in-class treatments for patients who have an unmet medical need. To learn more about PTC, please visit us at www.ptcbio.com and follow us on Facebook, on Twitter at @PTCBio, and on LinkedIn. For More Information: Media: Jane Baj +1 (908) 912-9167 jbaj@ptcbio.com Investors: Lisa Hayes +1 (732) 354 8687 lhayes@ptcbio.com Forward-Looking Statements: This press release contains forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. All statements contained in this release, other than statements of historic fact, are forward-looking statements, including statements regarding: the future expectations, plans and prospects for PTC; the enrollment, conduct, and results of studies for PTC299 during, or as a result of, the studies that could delay or prevent further development under the program, including any potential regulatory submissions; PTC's strategy, future operations, future financial position, future revenues, projected costs; and the objectives of management. Other forward-looking statements may be identified by the words "guidance", "plan," "anticipate," "believe," "estimate," "expect," "intend," "may," "target," "potential," "will," "would," "could," "should," "continue," and similar expressions. PTC's actual results, performance or achievements could differ materially from those expressed or implied by forward-looking statements it makes as a result of a variety of risks and uncertainties, including those related to: the outcome of pricing, coverage and reimbursement negotiations with third party payors for PTC's products or product candidates that PTC commercializes or may commercialize in the future; changes in tax and other laws, regulations, rates and policies; the eligible patient base and commercial potential of PTC's products and product candidates; PTC's scientific approach and general development progress; and the factors discussed in the "Risk Factors" section of PTC's most recent Quarterly Report on Form 10-Q and Annual Report on Form 10-K, as well as any updates to these risk factors filed from time to time in PTC's other filings with the SEC. You are urged to carefully consider all such factors. As with any pharmaceutical under development, there are significant risks in the development, regulatory approval and commercialization of new products. There are no guarantees that any product will receive or maintain regulatory approval in any territory, or prove to be commercially successful. The forward-looking statements contained herein represent PTC's views only as of the date of this press release and PTC does not undertake or plan to update or revise any such forward-looking statements to reflect actual results or changes in plans, prospects, assumptions, estimates or projections, or other circumstances occurring after the date of this press release except as required by law. SOURCE: PTC Therapeutics, Inc.