ENV-105 (carotuximab) in combination with XOFIGO (radium-223 dichloride)

July 22, 2026: Kairos Pharma, Ltd. (NYSE: KAPA) announced a strategic collaboration with Bayer to evaluate Kairos’ lead antibody ENV-105 (carotuximab; CD105/BMP signaling inhibitor) in combination with Bayer’s XOFIGO (radium-223 dichloride) for metastatic castration-resistant prostate cancer (mCRPC) involving bone.

Kairos cited Phase 2 data for ENV-105 in castrate-resistant prostate cancer, stating an 86% clinical benefit rate in resistant mCRPC and previously reported positive interim efficacy with median progression-free survival of more than 13 months versus standard of care; these interim Phase 2 data were presented at the 2025 ESMO Congress in Berlin.

The release notes Kairos is also running a Phase 1 trial of ENV-105 in EGFR-driven non-small cell lung cancer.

Background referenced: XOFIGO is FDA-approved for mCRPC with symptomatic bone metastases, and Bayer’s Phase III PEACE-3 trial showed a 24% reduction in mortality risk when XOFIGO was combined with enzalutamide (HR 0.76; p=0.009).