CytoAgents will present new clinical safety data for CTO1681 at the 67th American Society of Hematology annual meeting, where early findings from its Phase 1b/2a trial will be shown for the first time. The update marks a step forward for the company’s evaluation of the oral small molecule, which is being developed to help address inflammation-related toxicities in lymphoma patients receiving CAR T-cell therapy.

The company is enrolling patients in an ongoing study investigating CTO1681 as an immune modulator designed to target prostaglandin-mediated inflammation in the tumour microenvironment. CAR T-cell therapy remains associated with inflammatory toxicities such as cytokine release syndrome and neurotoxicity, and CytoAgents aims to explore whether CTO1681 could reduce the risk or severity of these effects.

The presentation at ASH will focus on preliminary safety data from the first patient cohort of the trial. The initial 10μg three-times-daily dose was well tolerated, with no dose-limiting toxicities and no drug-related serious adverse events reported. Following these observations, the company has opened enrolment for the next cohort at a 20μg three-times-daily dose.

Teresa Whalen, chief executive officer at CytoAgents, said: “New approaches to treat inflammation in the tumour microenvironment as well as black box warning toxicities, Cytokine Release Syndrome (CRS) and the neurotoxicity ICANS, continues to be an area of significant unmet medical need, with the majority of cancer patients undergoing CAR T treatment experiencing CRS and associated neurotoxicity. We look forward to sharing this initial positive safety data for CTO1681 at ASH and to continuing our advancement of CTO1681.”

The study seeks to generate a clearer picture of CTO1681’s safety, tolerability and pharmacodynamic effects before progressing to later-stage development. As CAR T-cell therapies continue to expand across lymphoma treatment, new approaches to support patient management remain an active area of investigation.

Poster details

Title: A phase 1b/2a study of CTO1681 for the prevention of cytokine release syndrome in patients with diffuse large B-cell lymphoma receiving chimeric antigen receptor T-cell therapy
Presenter: Jordan Gauthier, associate professor, clinical research division, Fred Hutchinson Cancer Center
Session: 704. Cellular immunotherapies: early phase clinical trials and toxicities: Poster III
Publication number: 5955
Date/time: Sunday 8 December 2025, 6pm–8pm ET
Location: Orange County Convention Center, West Halls B3–B4

CytoAgents also noted that results from its Phase 1 study in healthy adults, which assessed safety, tolerability, pharmacokinetics and pharmacodynamics across multiple ascending doses, have been accepted for online publication in the Blood annual meeting supplement. The abstract will appear in the November issue and be added to the Blood and ASH permanent archive.