CytomX Therapeutics said its Phase 1 study of CX-2051 in colorectal cancer has enrolled 73 patients across three dose-expansion cohorts—7.2 mg/kg, 8.6 mg/kg and 10 mg/kg administered every three weeks. The company disclosed that a single treatment-related Grade 5 adverse event, an acute kidney injury in a patient with a solitary kidney, was reported on 11 July and subsequently notified to the U.S. Food and Drug Administration on 18 July. A Safety Review Committee convened on 14 July endorsed continuation of the trial, allowing dosing to proceed at all levels. CytomX said the study remains active and that it remains on track to deliver a Phase 1 data update in the first quarter of 2026, reiterating guidance first given in January. The update was released to address recent online speculation about the programme.