Protoporphyrin lX Disodium

Completion of enrollment for phase 2 BEACON and AURORA studies of bitopertin in erythropoietic protoporphyria (EPP)Oral presentation at ASH meeting of updated interim data from BEACON, including a preliminary analysis of the precedented pivotal endpoint, cumulative time in sunlight over 6 months on days without painCompany will present preliminary data on pharmacodynamic activity from initial cohorts of phase 1b study of DISC-0974 in myelofibrosis (MF) patients with anemia, including changes in hemoglobinManagement will host a conference call on December 11th at 9:30 pm ET / 6:30 pm PT WATERTOWN, Mass., Nov. 02, 2023 (GLOBE NEWSWIRE) -- Disc Medicine, Inc. (NASDAQ:IRON), a clinical-stage biopharmaceutical company focused on the discovery, development, and commercialization of novel treatments for patients suffering from serious hematologic diseases, today announced several key updates and that it will present data from multiple programs in its hematology portfolio at the upcoming 65th American Society of Hematology (ASH) Annual Meeting and Exposition, which will be held in San Diego, CA on December 9-12, 2023. “We look forward to presenting updated interim data from all patients enrolled in the BEACON study at the upcoming ASH meeting, as well as preliminary clinical data from initial cohorts of both DISC-0974 anemia studies.” said John Quisel, J.D., Ph.D., President and Chief Executive Officer of Disc. “In addition, we’re pleased to announce the full enrollment of both the BEACON and AURORA studies of bitopertin in patients with EPP. We were able to enroll both trials in under a year, and I want to express my gratitude to our team, collaborators and the EPP community for helping us reach this important milestone.” Key Program Updates: Bitopertin Enrollment for phase 2 BEACON (n=22 adults) and AURORA (n=75 adults) studies of bitopertin in EPP is complete; BEACON has been expanded to enroll adolescents (age 12-18)Interim analyses of the BEACON trial (July 5, 2023 data cutoff) demonstrated significant and consistent improvements in light tolerance across patients: Observed magnitude of effects were comparable to previously reported improvements in sunlight toleranceAn initial sub-group analysis indicated that greater suppression of protoporphyrin IX (PPIX) was associated with increased maximal weekly sunlight tolerance: >10 hours of improvement on average in patients with a mean maximal PPIX reduction >30% (n=11) and >4 hours of improvement on average in patients with mean maximal PPIX reduction <30% (n=4) Updated BEACON data from all adult patients and with longer duration of therapy will be presented as an oral presentation at ASH, including: Measures of PPIX, photosensitivity, QOL, safety and tolerabilityPreliminary analysis of the precedented pivotal endpoint, cumulative time in light over 6 months on days without pain Topline AURORA data is expected to be presented in early 2024 DISC-0974 Dose escalation is ongoing for both phase 1b/2 studies of DISC-0974 in MF and anemia, and non-dialysis dependent chronic kidney disease (NDD-CKD)Initial data from the phase 1b/2 study of DISC-0974 in patients with MF and anemia will be presented at ASH Data from 10-20 patients in the dose-escalation phaseSafety and changes in hepcidin, iron, and hemoglobin levels Data from the 28 mg dose cohort of the phase 1b/2 study in NDD-CKD patients with anemia will be presented as part of the management call Bitopertin and DISC-0974 are investigational agents and are not approved for use as therapies in any jurisdiction worldwide. Details of Presentations and Abstracts The full abstracts are now available through the ASH conference website. Abstract Number: 923Title: Interim Analyses from the BEACON Trial: A Phase 2, Randomized, Open-Label Trial of Bitopertin in Erythropoietic Protoporphyria Date / Time: Monday, December 11, 5:30 PM PTSession: 102. Iron Homeostasis and Biology: Exploring Molecular Mechanisms and Therapeutic Options in Iron Homeostasis (Oral Presentation)Presenter: Gayle Ross, M.D. Abstract Number: 4564Title: A Phase 1b Trial of DISC-0974, an Anti-Hemojuvelin Antibody, in Patients with Myelofibrosis and Anemia Date / Time: Monday, December 11, 6:00-8:00 PM PTSession: 634. Myeloproliferative Syndromes: Clinical and Epidemiological: Poster IIIPresenter: William Savage, M.D., Ph.D. Other abstracts available on the ASH conference website: Abstract Number: 5224 (Online abstract only) Title: Anti-Hemojuvelin Monoclonal Antibody DISC-0974 Elicits a Durable and Consistent Response with Repeated Dosing in Cynomolgus Monkeys Abstract Number: 5236 (Online abstract only)Title: A Phase 1b Double-Blind, Placebo-Controlled Study of DISC-0974, an Anti-Hemojuvelin Antibody, in Patients with Non-Dialysis Dependent Chronic Kidney Disease and Anemia Abstract Number: 5228 (Online abstract only)Title: Application of a Validated Method for Quantifying Circulating Protoporphyrin IX to the Beacon Trial of Bitopertin in Erythropoietic Protoporphyria Webcast Conference Call Information Management will host a call on Monday, December 11th at 9:30 pm ET / 6:30 pm PT to review data and operational plans. Please register for management’s webcast on the Events and Presentations page of Disc’s website (https://ir.discmedicine.com/). About Disc Medicine Disc Medicine (NASDAQ:IRON) is a clinical-stage biopharmaceutical company committed to discovering, developing, and commercializing novel treatments for patients who suffer from serious hematologic diseases. We are building a portfolio of innovative, potentially first-in-class therapeutic candidates that aim to address a wide spectrum of hematologic diseases by targeting fundamental biological pathways of red blood cell biology, specifically heme biosynthesis and iron homeostasis. For more information, please visit www.discmedicine.com. Disc Cautionary Statement Regarding Forward-Looking Statements This press release contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, including, but not limited to, express or implied statements regarding Disc’s expectations with respect to its AURORA Phase 2 and BEACON Phase 2 clinical studies of bitopertin and the results thereof, and its Phase 1b/2 study of bitopertin in Diamond-Blackfan Anemia, its Phase 1b/2 clinical studies of DISC-0974 in patients with MF and NDD-CKD patients with anemia, projected timelines for the initiation and completion of its clinical trials, anticipated timing of release of data, and other clinical activities; and Disc’s business plans and objectives. The use of words such as, but not limited to, “believe,” “expect,” “estimate,” “project,” “intend,” “future,” “potential,” “continue,” “may,” “might,” “plan,” “will,” “should,” “seek,” “anticipate,” or “could” or the negative of these terms and other similar words or expressions that are intended to identify forward-looking statements. Forward-looking statements are neither historical facts nor assurances of future performance. Instead, they are based on Disc’s current beliefs, expectations and assumptions regarding the future of Disc’s business, future plans and strategies, clinical results and other future conditions. New risks and uncertainties may emerge from time to time, and it is not possible to predict all risks and uncertainties. No representations or warranties (expressed or implied) are made about the accuracy of any such forward-looking statements. Disc may not actually achieve the plans, intentions or expectations disclosed in these forward-looking statements, and investors should not place undue reliance on these forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements as a result of a number of material risks and uncertainties including but not limited to: the nature, strategy and focus of Disc; the difficulty in predicting the time and cost of development of Disc’s product candidates; Disc’s plans to research, develop and commercialize its current and future product candidates; that enrollment timelines of both the BEACON and AURORA studies may not necessarily be predictive of future enrollment timelines; the timing of initiation of Disc’s planned clinical trials; the timing of the availability of data from Disc’s clinical trials; Disc’s ability to identify additional product candidates with significant commercial potential and to expand its pipeline in hematological diseases; the timing and anticipated results of Disc’s preclinical studies and clinical trials and the risk that the results of Disc’s clinical trials may not be predictive of future results in connection with future studies or clinical trials and may not support further development and marketing approval; the other risks and uncertainties described in the “Risk Factors” section of our Annual Report on Form 10-K for the year ended December 31, 2022, Quarterly Reports on Form 10-Q for the quarters ended March 31, 2023 and June 30, 2023, and other documents filed by Disc from time to time with the SEC, as well as discussions of potential risks, uncertainties, and other important factors in Disc’s subsequent filings with the SEC. Any forward-looking statement speaks only as of the date on which it was made. None of Disc, nor its affiliates, advisors or representatives, undertake any obligation to publicly update or revise any forward-looking statement, whether as result of new information, future events or otherwise, except as required by law. Media Contact Peg RusconiVerge Scientific Communicationsprusconi@vergescientific.com Investor Relations Contact Christina TartagliaStern Investor Relationschristina.tartaglia@sternir.com

Until a few years ago, GlyT1, a glycine transporter, seemed like a promising target for an add-on therapy to treat negative symptoms of schizophrenia. But scientists were thrusted back to the drawing board in 2014, when Roche reported that its GlyT1 inhibitor, bitopertin, had failed two Phase III trials. A few months later, they scrapped the program altogether. The drug sat on the shelves for seven years. Then Disc Medicine came along. The biotech, which had licensed bitopertin from Roche in a $200 million deal with an undisclosed upfront, has now nabbed $90 million in Series B cash to take the drug in a completely different direction: rare genetic disorders known as erythropoietic porphyrias. Will Savage Disc Medicine had a lead program on its own: DISC-0974, an anemia drug that works by controlling iron metabolism and is already in the clinic. The hematology-focused company, though, had been researching other ways to treat diseases by going after “fundamental components” of pathways related to red blood cells, said CEO John Quisel, so as to fully take advantage of the expert network and capabilities it’s built. One of those pathways is heme synthesis. In erythropoietic porphyrias, a buildup of porphyrins lead to toxic reactions to sunlight — 30 minutes under the sun could cause severe pain and a burning sensation. Across a series of cellular and mouse experiments, researchers found that targeting a heme metabolite called protoporphyrin IX could fix the defect that results in porphyrin accumulation. Because Roche had been looking at glycine control as a way to treat schizophrenia patients, investigators had measured those metrics and showed that’s exactly what the drug did in patients — even though they were “hematologically normal.” Clinical data from thousands of patients also suggest a clean safety profile. While a host of GlyT1 inhibitors had been created, many had failed in earlier stages for safety or other reasons. Roche offered the best molecule with a solid clinical package. “It’s very rare to be able to move into a Phase II program with this kind of information already established by Roche,” Quisel said. “The task left for us at Disc is to demonstrate how much we are addressing the unmet need in EPP patients,” added Will Savage, who was promoted to CMO last week as part of a quartet of leadership changes. With the new cash infusion, the team — now standing at 20 — expects to have multiple Phase II trials for bitopertin and DISC-0974 up and running, then secure proof-of-concept data in 2023. Then there are the early-stage discovery programs lining behind. OrbiMed led the new round, joined by new investors Arix Bioscience, Janus Henderson Investors, 5AM Ventures, Rock Springs Capital, Nantahala Capital Management, Willett Advisors, and Alexandria Venture Investments. Existing backers, including Atlas Venture, Novo Holdings and Access Biotechnology, also participated.