Viridian Therapeutics Highlights Recent Progress and Reports Second Quarter 2024 Financial Results - THRIVE VRDN-001 global phase 3 clinical trial in active thyroid eye disease (TED) remains on track for topline readout

Viridian Therapeutics Highlights Recent Progress and Reports Second Quarter 2024 Financial Results

- THRIVE VRDN-001 global phase 3 clinical trial in active thyroid eye disease (TED) remains

topline readout in September 2024 -

- THRIVE-2 VRDN-001 global phase 3 clinical trial in chronic

TED topline readout expected year-end

2024; enrollment completed in July and exceeded its

- REVEAL-1 and REVEAL-2, global phase 3

clinical trials for subcutaneous VRDN-003 in patients with

active and chronic TED, on track

to initiate in August 2024 -

- Investigational New Drug (IND) submission for neonatal Fc receptor (FcRn) inhibitor VRDN-006 planned

by year-end 2024; non-human primate (NHP) data anticipated for half-life extended FcRn inhibitor VRDN-

008 in the second half of 2024 -

- Cash, cash equivalents, and short-term investments of $571.4 million as of June 30, 2024; provides

cash runway into the second half of 2026 -

WALTHAM, Mass., August 8, 2024 Viridian Therapeutics, Inc. (NASDAQ: VRDN), a biotechnology company focused on discovering and developing

potential best-in-class medicines for serious and rare diseases, today reported recent business highlights and financial results for the second quarter ending

Our team continues to execute across the board as shown by the progress we have made this quarter, and we are proud to report

solid progress in our TED portfolio, with both VRDN-001 phase 3 trials, THRIVE and THRIVE-2, exceeding enrollment targets, and

VRDN-003 trials, REVEAL-1 and REVEAL-2, planned to initiate this month, said Steve Mahoney, Viridian President and Chief

Executive Officer. All timelines within our FcRn portfolio remain on track, and we anticipate submitting an IND for VRDN-006 by year-end, and reporting NHP data

for VRDN-008 in the second half of the year. We look forward to delivering on these multiple key program milestones this year, beginning with our THRIVE readout next month.

Thyroid Eye Disease Portfolio

VRDN-001, an intravenously delivered anti-insulin-like growth factor-1 receptor (IGF-1R) antibody

VRDN-003, a potential best-in-class, subcutaneous, half-life extended anti-IGF-1R antibody designed as a

low-volume, infrequent, and self-administered subcutaneous injection

FcRn Inhibitor Portfolio

VRDN-006, a highly selective anti-FcRn Fc fragment designed to be a convenient

subcutaneous and self-administered option for patients

VRDN-008, a half-life extended FcRn inhibitor designed to prolong IgG suppression and provide a potentially

best-in-class subcutaneous option for patients

About Viridian Therapeutics

Viridian 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 protein engineering enables the development of

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 a pivotal program for VRDN-001, including two global phase 3 clinical trials (THRIVE and THRIVE-2), to evaluate its efficacy and safety in patients with active and chronic TED. Viridian is also advancing VRDN-003 as a potential best-in-class subcutaneous therapy for the treatment of TED, including two planned global phase 3 clinical trials, REVEAL-1 and

REVEAL-2, to evaluate the efficacy and safety of VRDN-003 in patients with active and chronic TED.

In addition to its TED portfolio, Viridian is advancing a novel portfolio of neonatal Fc receptor (FcRn) inhibitors, including

VRDN-006 and VRDN-008, which has the potential to be developed in multiple autoimmune diseases.

Viridian is based in Waltham, Massachusetts. For more information, please visit www.viridiantherapeutics.com. Follow Viridian on LinkedIn and

Forward Looking Statements

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, on track, plan, potential, predict, project,

design, should, target, will, or would or other similar terms or expressions that concern our expectations, plans and intentions. Forward-looking statements are neither historical facts nor

assurances of future performance. Instead, they are based on our current beliefs, expectations, and assumptions. Forward-looking statements include, without limitation, statements regarding: preclinical and clinical development of Viridian s

product candidates VRDN-001, VRDN-003, VRDN-006 and VRDN-008; anticipated start dates of

studies, including the initiation date of the REVEAL-1 and REVEAL-2, global phase 3 clinical trials for VRDN-003; milestones;

timelines; anticipated data results and timing of their disclosure, including topline results; regulatory interactions and anticipated timing of regulatory submissions, including the anticipated IND submission for

VRDN-006 and the anticipated BLA submission for VRDN-001; Viridian s expectation that its data package will support a BLA submission for VRDN-001 in the second half of 2025, pending data; Viridian s expectation that its data package will support a marketing authorization application in Europe for VRDN-001;

clinical trial designs, including the REVEAL-1 and REVEAL-2, global phase 3 clinical trials for VRDN-003; Viridian s plans

to launch VRDN-003 with a commercially available auto-injector pen, if approved; the potential utility, efficacy, potency, safety, clinical benefits, clinical response, convenience and number of indications of

VRDN-001, VRDN-003, VRDN-006 and VRDN-008; Viridian s product candidates potentially

being best-in-class; and that Viridian s cash, cash equivalents and short-term investments will be sufficient to fund its operations into the second half of 2026.

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: potential utility, efficacy,

potency, safety, clinical benefits, clinical response and convenience of Viridian s product candidates; that results or data from completed or ongoing clinical trials may not be representative of the results of ongoing or future

clinical trials; that preliminary data may not be representative of final data; the timing, progress and plans for our ongoing or future research, preclinical and clinical development programs;

changes to trial protocols for ongoing or new clinical trials, including adjustments that we may make to the VRDN-003 clinical trial designs as a result of the VRDN-001

data; expectations and changes regarding the timing for regulatory filings; regulatory interactions expectations and changes regarding the timing for enrollment and data; uncertainty and potential delays related to clinical drug development; the

duration and impact of regulatory delays in our clinical programs; the timing of and our ability to obtain and maintain regulatory approvals for our therapeutic candidates; manufacturing risks; competition from other therapies or products; estimates

of market size; other matters that could affect the sufficiency of existing cash, cash equivalents and short-term investments to fund operations; our financial position and projected cash runway; our future operating results and financial

performance; Viridian s intellectual property position; the timing of preclinical and clinical trial activities and reporting results from same; and those risks set forth under the caption Risk Factors in our most recent quarterly

report on Form 10-Q filed with the Securities and Exchange Commission (SEC) on August 8, 2024 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.

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS

(amounts in thousands, except share and per share data)

Viridian Therapeutics, Inc.

Selected Financial Information

Condensed Consolidated Balance Sheets

(amounts in thousands)

Louisa Stone, 617-272-4604

Manager, Investor Relations