Cynata Therapeutics advance to second cohort in stem cell trial

Stem cell and regenerative medicine company Cynata Therapeutics (ASX: CYP) has received an encouraging early response from the clinical trials of its stem cell product CYP-001, which began in November to treat steroid-resistant graft-versus-host disease.

Graft-versus-host disease is a medical complication that can occur following a bone marrow transplant or tissue graft, where the donated marrow or peripheral blood stem cells attack the recipient’s body, mistakenly identifying it as foreign.

Currently, the only approved treatment for the disease is corticosteroid therapy, which is typically only effective in about 50% of patients. If a patient’s condition fails to improve or even worsens, they are considered to be resistant to the steroid treatment.

In a “world first” clinical trial, Cynata is investigating the safety and efficacy of its mesenchymal stem cell product CYP-001 in steroid-resistant adult patients with the disease.

The first cohort of participants comprised of eight patients receiving two CYP-001 infusions at the lower end of the effective dose range – 1 million cells per kilogram of bodyweight, up to a maximum dose of 100 million cells. There was one week between the two infusions.

According to Cynata, all eight participants demonstrated at least a partial response to the treatment, which was defined as an improvement in the severity of their condition by at least one grade compared to the baseline.

As a result, the Data Safety Monitoring Board has recommended that Cynata’s clinical trial progress to a second cohort as planned.

The next eight participants to be enrolled in the second cohort will receive two CYP-001 infusions at a dose of 2 million cells per kg, up to a maximum dose of 200 million cells per infusion.

Cynata chief executive Dr Ross Macdonald said the positive recommendation by the monitoring board was an important milestone that would enable the company to complete its trial later this year.

“The improvement in [graft-versus-host disease] grade observed in 100% of these gravely ill people is very promising, especially given the low dose administered in Cohort A,” Macdonald said.

“A successful outcome will support the application of CYP-001 in many medically and commercially significant targets where therapeutic [mesenchymal stem cells] have shown promising results,” he added.

The company is currently enrolling patients for the second cohort at seven active sites across Australia and the United Kingdom.

The severity of graft-versus-host disease

According to medical research referenced by Cynata, mortality rates for steroid-resistant graft-versus-host disease patients are in excess of 90%.

The company also revealed in today’s announcement that unfortunately, one of the eight participants from the first cohort died after developing pneumonia.

However, pneumonia is a common outcome in recipients of bone marrow transplants and the death was not considered to be related to the trials or treatment, Cynata stated.

Cynata was granted a trading halt early on Monday prior to the announcement. By afternoon trade, shares were up 5.08% on the news.