Trial of New Agent for CRS in CAR T-Cell Recipients Advances from Its Initial Dosing Cohort

The investigational drug CTO1681 is under evaluation in a phase Ib/IIa clinical trial for the prevention and management of cytokine release syndrome (CRS) in chimeric antigen receptor (CAR) T-cell therapy recipients. This trial has successfully completed its first dose, core cohort dose-limiting toxicity observation period, and is proceeding to the second cohort with its planned increased dose. CytoAgents Inc., the developer of CTO1681 and conductor of the trial, issued a press release announcing this progress.

About the trial’s results thus far, CytoAgents’ chief medical officer, Arthur P Bertolino, MD, PhD, MBA, remarked, “[t]he safety and early efficacy data from the first dose cohort are encouraging. We look forward to evaluating the higher dose cohorts to further study the potential of CTO1681 to prevent and treat CRS, a very significant toxicity of CAR T-cell therapy.”

CTO1681 is a novel agent whose mechanism of action to counter CRS involves the patient’s natural immune response to disease. The phase Ib/IIa trial is an open-label, rolling six-dose-escalation, multicenter study to evaluate the agent’s safety, pharmacokinetics, and preliminary efficacy and determine its recommended phase 2 dose.

The trial’s first-dosing cohort comprised patients who underwent CAR T-cell therapy for diffuse large B-cell lymphoma. CTO1681 produced favorable safety results in this cohort, with no dose-limiting toxicities, drug-related serious adverse events, or interference with CAR T-cell therapy. Based on these data, the Safety Review Committee approved dose-escalation in the trial and proceeded to cohort 2.

Reference

CytoAgents. Press release. Businesswire. April 24, 2025. Accessed April 28, 2025. https://www.businesswire.com/news/home/20250424559289/en/CytoAgents-Announces-Completion-of-Cohort-1-Dose-escalation-Stage-of-Clinical-Phase-1B-to-Advance-Research-on-Cytokine-Release-Syndrome