Kairos Pharma signs research agreement with Bayer to test ENV-105 with XOFIGO in prostate cancer

Kairos Pharma, Ltd. (NYSE American: KAPA) disclosed in an 8-K that on July 16, 2026 it entered into an Agreement for the Support of Investigator/Institution Initiated Research with Bayer HealthCare Pharmaceuticals Inc. Under the agreement, Bayer will supply radium so Kairos can study how radium performs together with ENV-105 (carotuximab) in models of prostate cancer bone metastasis.¹ The company announced the collaboration publicly on July 22, 2026.

The partnership pairs Kairos's lead antibody ENV-105, a first-in-class CD105/BMP signaling inhibitor, with Bayer's XOFIGO (radium-223 dichloride) in metastatic castration-resistant prostate cancer involving bone.¹ Kairos is responsible for running and funding the study, but under the deal terms it must share its final analysis and conclusions with Bayer within six months after the study wraps up, and it needs Bayer's sign-off before making any major changes to the study's protocols.¹

Kairos currently has two other clinical programs for ENV-105: a Phase 1 trial in EGFR-driven non-small cell lung cancer, and a separate Phase 2 study in castrate resistant prostate cancer.¹ The company reported last year that interim data from the Phase 2 prostate cancer trial showed median progression-free survival topping 13 months, which it called a significant improvement over standard of care, with the data presented at the 2025 ESMO Congress in Berlin.¹

On the radiopharmaceutical side, XOFIGO holds FDA approval as an alpha-emitting agent for mCRPC patients with symptomatic bone metastases, and Bayer has been running additional combination studies, including the Phase III PEACE-3 trial, which showed a 24% reduction in mortality risk when paired with enzalutamide (HR 0.76; p=0.009).¹

The IIR Agreement was filed as Exhibit 10.1 to the 8-K, with the press release included as Exhibit 99.1.