“These data represent an important clinical milestone for ETX-19477 and for the emerging field of PARG inhibition,” said Jeffrey A. Stafford, CEO of 858 Therapeutics. “We are encouraged by the clinical efficacy and RECIST responses observed to date, in both ovarian and breast cancer patients. These treatment outcomes, together with the robust PK-PD relationship established during dose escalation, support the continued development of ETX-19477, including combination approaches that can meaningfully expand the patient populations treatable with ETX-19477.”