ENGINEERING MEDICINES TO IMPROVE PATIENT CARE Investors News Release Details Viridian Therapeutics Announces Presentations at the 2023 Annual Meeting of the Endocrine Society June 13, 2023 PDF Version - Oral presentation to describe distinct receptor binding and mechanistic characteristics of VRDN-001, Company’s lead pipeline candidate in its thyroid eye disease program - - Poster presentations to feature data from ongoing Phase 1/2 trial of VRDN-001 - WALTHAM, Mass.--(BUSINESS WIRE)--Jun. 13, 2023-- Viridian Therapeutics, Inc. (NASDAQ: VRDN), a biopharmaceutical company focused on discovering and developing potential best-in-class medicines for serious and rare diseases, today announced that multiple abstracts featuring data on the Company’s lead investigational therapy for the treatment of thyroid eye disease (TED) will be presented at the Annual Meeting of the Endocrine Society (ENDO 2023) to be held June 15-18, 2023, in Chicago, Illinois. An oral presentation will highlight mechanistic features of VRDN-001, a full antagonist antibody to the insulin-like growth factor-1 receptor (IGF-1R), in development for TED, while poster presentations will include clinical data from Viridian’s ongoing Phase 1/2 trial of VRDN-001 as well as pharmacodynamic responses in healthy volunteers and patients with active TED receiving VRDN-001. Oral Presentation Title: VRDN-001, a Full Antagonist Antibody to IGF-1 Receptor in Development for Thyroid Eye Disease (TED), Binds to a Distinct Epitope from Teprotumumab Session: Thyroid Physiology—From the lab to the patient Information: Saturday, June 17, 2023, 3:45 to 4:00 pm CDT, Session #OR26 Poster Presentations Title: Durability of Treatment Response With VRDN-001, a Full Antagonist Antibody to IGF-1 Receptor, in Patients with Thyroid Eye Disease (TED): Phase 1/2 Clinical Study* Session: Thyroid Biology & Cancer: Thyroid Autoimmunity Information: Friday, June 16, 2023, 12:00 to 1:00 pm CDT, Poster #FRI-545 * During this session, this abstract will also be featured as a Rapid Fire oral presentation #RF-11 Title: VRDN-001, a Full Antagonist Antibody to IGF-1 Receptor in Development for Thyroid Eye Disease (TED): Pharmacodynamic Responses in Healthy Volunteers and Patients with Active TED Session: Thyroid Biology & Cancer: Thyroid Autoimmunity Information: Friday, June 16, 2023, 12:00 to 1:00 pm CDT, Poster #FRI-546 Clinical data in these presentations relate exclusively to treatment of patients with active TED. The Company plans to provide an update in June or July of this year on the treatment of patients with chronic TED. Following their presentation at ENDO 2023, the above abstracts will be posted at www.viridiantherapeutics.com/pipeline/scientific-presentations. About Viridian’s Thyroid Eye Disease Pipeline (VRDN-001, -002, and -003) Viridian’s lead product candidate, VRDN-001, is a differentiated monoclonal antibody targeting insulin-like growth factor-1 receptor (IGF-1R), a clinically and commercially validated target for the treatment of thyroid eye disease (TED). In preclinical studies, VRDN-001 was shown to be a full antagonist of IGF-1R, with more complete receptor blockade than other anti-IGF-1R antibodies, including the only currently approved TED therapy. Preliminary data from the initial dose cohorts of the Phase 2 portion of the ongoing trial established clinical proof-of-concept for VRDN-001 in patients with active TED: treatment with VRDN-001 led to clinically meaningful reductions in proptosis, improvement in clinical activity score (CAS), and diplopia resolution. VRDN-001 had a favorable safety profile and was well tolerated in the trial. The Company is running a Phase 3 trial, known as THRIVE, in patients with active TED. VRDN-001 is also being evaluated in Phase 2 trial cohorts in patients with chronic TED. Pending the release of that data, the Company plans to initiate its THRIVE-2 Phase 3 trial in patients with chronic TED. The Company is advancing VRDN-001, VRDN-002, and VRDN-003 as subcutaneous (SC) program candidates. All three candidates have the potential to be developed for self-administration by a convenient, SC pen device. VRDN-001 IV’s low-dose data support its potential as a SC candidate. VRDN-002 is a novel anti-IGF-1R monoclonal antibody incorporating half-life extension technology. VRDN-003 is an anti-IGF-1R monoclonal antibody with the same amino acid sequence as VRDN-001, except for the addition of the half-life extension technology that is incorporated in VRDN-002. VRDN-001, -002, and -003 are investigational therapies that are not approved for any use in any country. About TED TED is a serious and debilitating rare autoimmune disease that causes inflammation within the orbit of the eye that can cause double vision, pain, and potential blindness. TED is a progressive disease consisting of an initial active phase, followed by a transition to a secondary chronic phase. More than 50,000 and 200,000 people are estimated to suffer from active and chronic TED, respectively, in the United States and Europe. About Viridian Therapeutics Viridian Therapeutics is a biopharmaceutical company focused on engineering and developing potential best-in-class medicines for patients with serious and rare diseases. Viridian’s expertise in antibody discovery and engineering enables it to develop differentiated therapeutic candidates for previously validated drug targets in commercially established disease areas. Viridian is advancing multiple candidates in the clinic for the treatment of patients with thyroid eye disease (TED). The Company is conducting its first global Phase 3 trial called ‘THRIVE’ to evaluate the safety and efficacy of VRDN-001 in patients with active TED. Viridian is also evaluating VRDN-001 in a Phase 2 proof-of-concept trial in patients with chronic TED. In addition to its program for intravenously administered VRDN-001, the Company is advancing three candidates for its subcutaneous strategy with the goal of providing a more conveniently administered therapy to patients with TED. Viridian is also developing multiple preclinical assets in autoimmune and rare diseases. Viridian is based in Waltham, Massachusetts. For more information, please visit www.viridiantherapeutics.com. Follow Viridian on LinkedIn and twitter. Note Regarding Forward-Looking Statements This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements may be identified by the use of words such as, but not limited to, "anticipate," "believe," "continue," "could," "estimate," "expect," "intend," "may," "might," "plan," "potential," "predict," "project," "should," "target," "will," or "would" or other similar terms or expressions that concern the Company’s expectations, plans and intentions. Forward-looking statements include, without limitation, statements regarding the Company’s expectations, strategies, plans and intentions. Forward-looking statements are neither historical facts nor assurances of future performance. Instead, they are based on the Company’s current beliefs, expectations, and assumptions. 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. Such forward-looking statements are subject to a number of material risks and uncertainties including but not limited to: the potential efficacy and safety of VRDN-001, VRDN-002 and VRDN-003 for the treatment of TED, the timing progress and plans for the Company’s ongoing and future research and clinical development plans, trial protocols for ongoing or future clinical trials, including the clinical trials for VRDN-001, VRDN-002 and VRDN-003, including those risks set forth under the caption “Risk Factors” in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC) on March 9, 2023 and other subsequent disclosure documents filed with the SEC. Any forward-looking statement speaks only as of the date on which it was made. Neither the Company, nor its affiliates, advisors, or representatives, undertake any obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by law. These forward-looking statements should not be relied upon as representing the Company’s views as of any date subsequent to the date hereof. Source: Viridian Therapeutics, Inc. View source version on businesswire.com: https://www.businesswire.com/news/home/20230613522439/en/ Investors: Louisa Stone, 508-808-2400 Manager, Investor Relations IR@viridiantherapeutics.com Todd James, 617-272-4691 Senior Vice President, Corporate Affairs and Investor Relations IR@viridiantherapeutics.com Media: Matt Fearer, 617-272-4605 Vice President, Corporate Communications Media@viridiantherapeutics.com Source: Viridian Therapeutics, Inc.