Editas Medicine, Inc.

Key EDIT-401 data presented include:

•In an oral presentation at ASGCT, Editas reported that a single dose of EDIT-401 achieved ≥90 percent mean LDL-C reduction across all dose groups in non-human primates (NHPs).

o≥90 percent mean LDL-C reduction was achieved with only moderate levels (10-40 percent) of functional editing of LDLR alleles and ≥6-fold mean increase in hepatic LDLR protein.

o LDL-C lowering was rapid and remained durable across evaluated dose levels (1.5 mg/kg-3.0 mg/kg) through ~6 months.

o Promising preclinical safety profile with no adverse clinical observations at therapeutically relevant dose (1.5 mg/kg).

o The highest delivery of EDIT-401 was observed in the hepatocytes as compared to other non-target tissues with undetectable oocyte delivery.

•In an oral presentation at TIDES, Editas presented data demonstrating EDIT-401 dose-dependent LDL-C reduction in NHPs.

•In a poster presentation at ASGCT, Editas reported that data evaluating pharmacokinetics and pharmacodynamics of a single dose of EDIT-401(mu) across multiple dose levels in heterozygous Ldlr loss-of-function mice and wildtype mice support that dose adjustments may not be needed to achieve LDL-C lowering in Heterozygous Familial Hypercholesterolemia (HeFH) patients.