Schrödinger discontinued its CDC7 inhibitor SGR-2921 development following the deaths of two AML patients in a Phase I trial. Despite promising preclinical and early monotherapy activity, safety concerns related to severe adverse events prompted the halt. The decision underscores the challenges of targeting cell cycle regulators in oncology. Schrödinger retains other cancer candidates but pivots from CDC7 inhibition amid evolving safety and efficacy data.