Regeneron’s prostate cancer bispecific antibody trial has been halted due to two deaths

CAR-T Digest - August 2020

04 Aug 2023: REGN5678 / Cemiplimab-rwlc / Advanced Prostate Cancer / Regeneron: Two deaths reported resulting in a halt of the study

In Regeneron’s Q2 2023 report, the Company shared that the ongoing study Phase 1/2 study of REGN5678 + Libtayo has resulted in two immune-mediated Grade 5 adverse events (death), including one in July 2023
As a result, the company has discontinued enrolment of patients receiving the combination of REGN5678 and full-dose Libtayo, and plans to explore REGN5678 combinations with lower doses of Libtayo
Also, plans to enroll patients in a REGN5678 monotherapy cohort, as well as in combination with other immunotherapy modalities
During Q2 2022 earnings call, the company underscored encouraging data for REGN5678, a “homegrown” asset, when used in combination with Libtayo
REGN5678 is designed to amplify the connection between PSMA-expressing tumor cells and CD28, a costimulatory receptor found in T-cells