Editas Medicine, Inc. Q4 FY2023 earnings call

• Accelerated clinical development of Reni-cel, exceeding enrollment goals and sharing clinical updates in 2023. Strengthened in vivo discovery capabilities with the hiring of Linda Burkly. Increased business development, including licensing Cas9 IP to Vertex. For Reni-cel: Enrolled 40 sickle cell and 9 beta thalassemia patients, dosed 18 RUBY and 7 EdiTHAL patients, aligned with FDA on RUBY trial as Phase 1, 2, 3, and initiated adolescent cohort in RUBY. Clinical data from Reni-cel showed robust correction of anemia, increased fetal hemoglobin, and no vaso-occlusive events. In vivo pipeline aims to establish preclinical proof-of-concept for an undisclosed indication in 2024.

Editas Medicine's financials for the fourth quarter of 2023 showed revenue of $60 million, primarily from the license agreement with Vertex. R&D expenses were $70 million, up $18 million from Q4 2022 but offset by reprioritization on the Reni-cel program. G&A expenses were $14 million, down from $18 million in Q4 2022 due to reduced patent and legal costs. The Reni-cel program had enrolled 40 sickle cell and 9 beta thalassemia patients, with 18 RUBY and 7 EdiTHAL patients dosed. The in vivo discovery capabilities were strengthened with the hiring of Linda Burkly, and business development included granting Vertex a license for Cas9 IP, extending cash runway into 2026.

• In 2024, provide clinical updates from RUBY and EdiTHAL trials in mid-2024 and year-end. Complete adult cohort enrollment and initiate adolescent cohort in RUBY, continue enrollment in EdiTHAL. Establish in vivo preclinical proof-of-concept for an undisclosed indication. Leverage IP portfolio and business development to drive value.

• Regulatory risks related to FDA approval for Reni-cel. Concerns about off-target editing, though Editas believes its AsCas12a enzyme has robust off-target oversight. Potential challenges in transitioning clinical trial sites to commercial manufacturing.

Q: Could you please elaborate on the hemolysis markers that you're tracking and tell us how they will relate to patient-reported outcomes such as quality of life?

A: Baisong Mei mentioned tracking markers like reticulocyte, LDH, bilirubin, and using general and sickle cell-specific patient-reported outcome instruments.

Q: Can you share just any additional insights into your FDA conversation as you aligned on the RUBY trial specifically in terms of the number of patients you'll need and the amount of follow-up you'll need to file a potential BLA?

A: Baisong Mei stated alignment with FDA on RUBY trial as Phase 1, 2, 3, continuing engagement for BLA data package and follow-up.

Q: Now that there is a gene editing treatment approved in sickle cell, what are your latest thoughts on how reni-cel would fit in the space? And what have you learned from the early launch by the competitor?

A: Caren Deardorf said there's strong interest, market developing, and reni-cel's differentiation will be timed well with ongoing data collection.

Q: Did the alignment with the FDA include any feedback on off-target editing, profiling akin to sort of the AdCom's criticism around CASGEVY's characterization for the breadth of genetic diversity?

A: Baisong Mei mentioned continuous FDA engagement, confident in off-target editing data with AsCas12a enzyme.

Q: We're just wondering about the mid-year readout from the RUBY trial. I think you have 18 patients dosed to-date. Are you going to report data on these 18 patients plus any additional patient dosed with a certain amount of follow-up at the time of readout?

A: Gilmore O'Neill and Baisong Mei stated confidence in mid-year data with more dosed patients and robust correction of anemia