Does anyone have any knowledge of REGN5678

From Google AI: “it appears that Regeneron has discontinued enrollment of patients receiving the combination of REGN5678 and full-dose Libtayo. This decision was made due to safety concerns, specifically the occurrence of two immune-mediated deaths in patients receiving this combination.”

“However, Regeneron is not giving up on REGN5678 entirely. They are still exploring its potential:
Exploring combinations with lower doses of Libtayo.
Planning to enroll patients in a REGN5678 monotherapy cohort.
Exploring combinations with other immunotherapy modalities.
Therefore, while the specific combination of REGN5678 with full-dose Libtayo has been discontinued, the overall development program for REGN5678 is continuing in a revised form.”

Libtayo is a PD-1 checkpoint inhibitor.

Phil

Different medicine, a recent announcement from June 1, 2025 (from article title on Johnson and Johnson’s website):

Johnson & Johnson unveils first-in-human results for pasritamig, showing early anti-tumor activity in prostate cancer

Pasritamig, a first-in-class bispecific T-cell-engaging antibody, shows potential in mCRPC with outpatient dosing designed for the community setting

Data show low rates of treatment-related adverse events, signaling human kallikrein 2 (KLK2) as a novel, highly specific target