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editas MEDICINE Editas Medicine Announces Third Quarter 2021 Results and Business Updates November 8 , 2021 EDIT - 101 Phase 1/2 BRILLIANCE trial initial clinical data demonstrated favorable safety profile and preliminary evidence of clinical benefit ; enrollment ongoing in adult high - dose and pediatric mid - dose cohorts EDIT - 301 Phase 1/2 RUBY trial for the treatment of sickle cell disease currently enrolling study participants Presented preclinical data on novel SLEEK gene editing technology enabling high efficiency , multi - transgene knock - in in multiple clinically relevant cell types CAMBRIDGE , Mass . ,, Nov. 08 , 2021 ( GLOBE NEWSWIRE ) Editas Medicine , Inc. ( Nasdaq : EDIT ) , a leading genome editing company , today reported business highlights and financial results for the third quarter of 2021 . " Editas recently marked an important milestone with the presentation of initial EDIT - 101 results demonstrating a favorable safely profile and encouraging signals of clinical activity and evidence of ocular gene editing . Encouraged by these data , we look forward to obtaining additional clinical results , including from our ongoing adult high - dose and pediatric mid - dose cohorts , " said James C. Mullen , Chairman , President , and Chief Executive Officer , Editas Medicine . " We have also continued to make excellent progress advancing our broader clinical and preclinical programs , including the expansion of our gene editing capabilities , as exemplified by our proprietary SLEEK knock - in technology , which we are already applying in our iNK program for solid tumors . " Recent Achievements and Outlook In Vivo Gene Edited Medicines • EDIT - 101 for Leber Congenital Amaurosis 10 ( LCA10 ) , a CEP290 - Related Retinal Degenerative Disorder Initial clinical data demonstrated favorable safety profile , and efficacy signals in the mid - dose cohort provided initial evidence for clinical benefit Editas Medicine presented initial clinical data from the ongoing , open label Phase 1/2 BRILLIANCE clinical trial of EDIT - 101 for the treatment of LCA10 . The data included preliminary patient safety and efficacy assessments on the first two cohorts . No serious adverse events or dose - limiting toxicities were reported in the first six adult subjects treated with the low or mid doses of EDIT - 101 . In addition , early efficacy signals in the mid dose cohort provided clinical evidence of gene editing and suggest potential clinical benefits . The Company believes these initial data validate Editas Medicine's in vivo platform's proof of concept and provide support for the advancement of the adult high - dose cohort and the pediatric mid - dose cohort . The Company will continue to assess patients in the adult low - dose and mid - dose cohorts while it enrolls and treats patients in the adult high - dose and pediatric mid - dose cohorts . The Company remains on track to complete dosing of the adult high - dose and pediatric mid - dose cohorts in the first half of 2022 . Ex Vivo Gene Edited Medicines • EDIT - 301 for Sickle Cell Disease Enrolling patients for initial dosing The Company is developing EDIT - 301 for the treatment of sickle cell disease . Editas Medicine uses a proprietary engineered CRISPR / Cas12a ribonucleoprotein ( RNP ) to edit the HBG1 / 2 promoter mimicking a benign and naturally occurring human fetal hemoglobin mutation . This site is a naturally validated location , as patients with Hereditary Persistence of Fetal Hemoglobin ( HPFH ) harbor the sickle cell mutation but do not exhibit symptoms of the disease . The Company believes that targeting this site is potentially a more effective approach with better long - term safety than editing the BCL11A enhancer . The Phase 1/2 RUBY trial for the treatment of sickle cell disease is currently enrolling study participants and expects to begin dosing in the first half of 2022 . • EDIT - 301 for Transfusion - Dependent Beta Thalassemia ( TDT ) Preclinical data supporting potential treatment for TDT to be presented at ASH The Company will present preclinical data on EDIT - 301 for the treatment of transfusion - dependent beta thalassemia at the 63rd American Society of Hematology Annual Meeting & Exposition ( ASH ) . The data will demonstrate that edited beta thalassemia CD34 + cells show significant improvement in erythroid maturation and health , accompanied by significantly increased total hemoglobin content per cell . These data support the hypothesis that editing of the HBG1 / 2 promoter using an engineered AsCas12a RNP may reverse red blood cell abnormalities associated with the disease and increase hemoglobin production . The Company believes that EDIT - 301 has the potential to be an efficacious autologous cell therapy