Editas Medicine : January 2021 Corporate Presentation

Corporate Presentation

January 25, 2021

Forward Looking Statements

This presentation contains forward-looking statements and information within the meaning of The Private Securities Litigation Reform Act of 1995. The words ''anticipate,'' ''believe,'' ''continue,'' ''could,'' ''estimate,'' ''expect,'' ''intend,'' ''may,'' ''plan,'' ''potential,'' ''predict,'' ''project,'' ''target,'' ''should,'' ''would,'' and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Forward-looking statements in this presentation include statements regarding the initiation, timing, progress and results of the Company's preclinical and clinical studies and its research and development programs, including dosing the first patient in the adult mid-dose cohort in the BRILLIANCE trial in Q1 2021, the initiation of the RUBY trial and filing an IND for EDIT-301 for the treatment of beta-thalassemia by the end of 2021, the timing for the Company's receipt and presentation of data from its clinical trials and preclinical studies, the timing or likelihood of regulatory filings and approvals, and the therapeutic and market potential of the Company's product candidates. The Company may not actually achieve the plans, intentions, or expectations disclosed in these forward-looking statements, and you 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 these forward-looking statements as a result of various factors, including: uncertainties inherent in the initiation and completion of preclinical studies and clinical trials and clinical development of the Company's product candidates; availability and timing of results from preclinical studies and clinical trials; whether interim results from a clinical trial will be predictive of the final results of the trial or the results of future trials; expectations for regulatory approvals to conduct trials or to market products and availability of funding sufficient for the Company's foreseeable and unforeseeable operating expenses and capital expenditure requirements. Those risks and uncertainties include, among other things, that the Company's expectations regarding the effects of COVID-19 may be incorrect, that data from the Company's development programs may not support registration or further development of its potential medicines due to safety, efficacy or other reasons, and other risks listed under "Risk Factors" included in the Company's most recent Quarterly Report on Form 10-Q, which is on file with the Securities and Exchange Commission, and in other filings that the Company may make with the Securities and Exchange Commission in the future. Any forward-looking statements contained in this presentation represent Company's views only as of the date hereof and should not be relied upon as representing its views as of any subsequent date. Except as required by law, the Company explicitly disclaims any obligation to update any forward-looking statements.

© 2020 Editas Medicine 2

Gene Editing Transforms Medicines

Gene EDITed medicines offer potential cures to

patients with severe diseases

Potential for…

Superior efficacy	One-time curative treatments
Treating untreatable diseases	Improved safety
Durable response	Greater precision

Expanding and accelerating the possibility of in vivo and ex vivo genomic medicines

© 2020 Editas Medicine 3

Leader in Genomic Medicine

Only company with a portfolio of proprietary CRISPR Cas9 and Cas12a

enzymes to address the widest range of diseases

In Vivo Gene EDITed Medicines		Ex Vivo Gene EDITed Cell Medicines

Leverage smaller Staph. aureus Cas9 and AAV	Leverage Cas12a for
delivery technology for enhanced efficiency in	enhanced efficiency and editing specificity for
ocular, neurological, and future therapeutic areas	hemoglobinopathies and solid tumors

Best-in-class gene editing platform, broadest intellectual property,

flexible and robust manufacturing capabilities, led by seasoned executive team

Cas9: CRISPR-associated protein 9	© 2020 Editas Medicine 4
Cas12a: CRISPR-associated protein 12a