Disc Reports Topline Results from Phase 2 AURORA Study of Bitopertin in Patients with Erythropoietic Protoporphyria (EPP)

Disc Reports Topline Results from Phase 2 AURORA Study of Bitopertin in Patients with Erythropoietic Protoporphyria

WATERTOWN, Mass., April 01, 2024 (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 presented topline data from AURORA, a phase 2 study of bitopertin in patients with EPP.

Treatment with bitopertin resulted in statistically significant reductions in PPIX, the primary endpoint, and significant improvements in the rate of phototoxic reactions with pain and the Patient Global Impression of Change (PGIC). On the key

secondary endpoint of cumulative time in sunlight on days without pain, bitopertin patients had a positive response consistent with BEACON results, but the endpoint did not meet statistical significance due to strong placebo performance.

This study has confirmed that bitopertin significantly reduces the toxic metabolite, PPIX, in patients with EPP, and we have shown that

bitopertin-treated patients experience improvements in the clinically meaningful outcomes of Patient Global Impression of Change and the number and rate of phototoxic reactions with pain, with the 60 mg dose reaching statistical significance

compared to placebo. Despite the strong performance of bitopertin on the key secondary endpoint of cumulative time in light, consistent with results seen in BEACON, statistical significance was not met due to an outsized placebo response, said

John Quisel, J.D., Ph.D., President and Chief Executive Officer. Given that, we will need to conduct an analysis of our final data set and work with investigators, regulators, and patient advocacy groups to define the optimal registrational

endpoints moving forward. While we do this additional work, we continue to be excited about the upcoming readouts from our other programs, including updated data from our DISC-0974 study in anemia of myelofibrosis in Q2.

The AURORA study is a randomized, double-blind, placebo-controlled phase 2 study that enrolled 75 adult subjects with EPP. Subjects were randomized 1:1:1 to

receive 20 mg of bitopertin, 60 mg of bitopertin, or placebo once daily for 17 weeks.

Summary of topline results

Webcast Conference Call Information

Management will host

a call on Monday, April 1 at 8:30 am ET to review the data. Please register for management s webcast on the Events and Presentations page of Disc s website ( https://ir.discmedicine.com/).

Bitopertin is an investigational,

clinical-stage, orally-administered inhibitor of glycine transporter 1 (GlyT1) that is designed to modulate heme biosynthesis. GlyT1 is a membrane transporter expressed on developing red blood cells and is required to supply sufficient glycine for

heme biosynthesis and support erythropoiesis. Disc is planning to develop bitopertin as a potential treatment for a range of hematologic diseases including erythropoietic porphyrias, where it has potential to be the first disease-modifying therapy.

There are currently two ongoing phase 2 clinical trials of bitopertin in patients with EPP that have fully enrolled and have had key data readouts: the open-label trial called BEACON and a randomized, double-blind placebo-controlled trial called

Bitopertin is an investigational agent and is not approved for use as a therapy in any jurisdiction worldwide. Disc obtained global rights to

bitopertin under a license agreement from Roche in May 2021.

About Erythropoietic Protoporphyria (EPP) and

X-linked Protoporphyria (XLP)

Erythropoietic protoporphyria (EPP) and

X-linked Protoporphyria (XLP) are rare, debilitating and potentially life-threatening diseases caused by mutations that affect heme biosynthesis, resulting in the accumulation of a toxic, photoactive

intermediate called protoporphyrin IX (PPIX). This causes severe reactions when patients are exposed to sunlight, characterized by excruciating pain, edema, burning sensations and potential blistering and disfigurement. PPIX also accumulates in the

hepatobiliary system and can result in complications including gallstones, cholestasis, and liver damage in 20-30% of patients and in extreme cases liver failure. Current standard of care involves extreme

measures to avoid sunlight, including restricting outdoor activities to nighttime, use of protective clothing and opaque shields, and pain management. This has a significant impact on the psychosocial development, quality of life, and daily

activities of patients, particularly in young children and families. There is currently no cure for EPP and only one FDA-approved therapy, a surgically implanted synthetic hormone designed to stimulate melanin

production called Scenesse (afamelanotide).

Disc Medicine 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 Medicine 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 BEACON Phase 2 clinical studies of bitopertin and projected timelines for the initiation and completion of its clinical trials and other activities.

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 adequacy of Disc s capital to support its future operations and its ability to successfully initiate and complete clinical

trials; 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; the

timing of initiation of Disc s planned preclinical studies and 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 preclinical studies and 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, 2023 and other documents filed by Disc from time to time with the Securities and Exchange Commission (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.

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