Cynata Therapeutics (ASX:CYP) decided to terminate a phase 2 clinical trial of CYP-001 in patients with high-risk acute graft versus host disease after primary evaluation results failed to meet expectations, according to a Wednesday filing with the Australian bourse.

The results showed no significant differences between the active and control groups in the primary endpoint of overall response rate or in the trial's key secondary endpoints, per the filing.

The phase 1 results for CYP-001 were "very positive," but the latest outcome fell "well short of what we were hoping for," said Cynata CEO Kilian Kelly.

The company will remain under voluntary suspension from ASX trading pending the results of a phase 3 trial of CYP-004 in patients with knee osteoarthritis, which are expected to be released within the week.