Australian stem cell and regenerative medicine company Cynata Therapeutics (ASX: CYP) may advance to a phase 2 clinical trial of a new stem cell drug if results of an initial two-stage trial continue to prove the drug’s safety and efficacy.
The company has reported positive results on day 28 of the second stage of a phase 1 trial of CYP-001, developed to treat medical complications arising from bone marrow transplants.
The trial, which has been split over two test groups (cohort A and cohort B), aims to assess the safety and tolerability of different CYP-001 doses, Cynata’s Cymerus™ mesenchymal stem cell (MSC) product candidate.
The drug has been developed to treat acute graft versus host disease (GvHD), a serious and sometimes-fatal steroid-resistant condition, which can develop after a bone marrow transplant, whereby the donor’s immune cells (the “graft”) attack the recipient (the “host”).
In February this year, Cynata reported “excellent data” from cohort A patients who commenced GvHD treatment with two low doses of CYP-001 (one million cells per kilogram of bodyweight, up to a maximum of 100 million cells per infusion).
Doses were administered seven days apart, and by the end of the 100-day preliminary evaluation period, all patients had demonstrated either a partial or complete response in the severity of their GvHD symptoms.
This week, Cynata announced early success with the second stage trial involving cohort B patients receiving CYP-001 at twice the dosage of cohort A (2 million cells per kilogram of body weight, up to a maximum of 200 million cells per infusion).
By day 28 of the 100-day evaluation period, cohort B patients had recorded a partial response rate of 86% and a complete response rate of 57%, suggesting that the drug may be tolerated at a higher dose and may support the advancement of CYP-001 into a phase 2 trial.
“These [cohort B] results are particularly impressive given that all patients enrolled in the trial had failed to respond to corticosteroid therapy, [which is currently] the only approved treatment for GvHD,” said Cynata’s vice president of product development Dr Kilian Kelly.
“There have been no safety concerns reported in either patient cohort [and] the data suggests the higher dose level has elicited a much quicker treatment response.”
Cynata chief executive officer Dr Ross Macdonald said the phase 1 CYP-001 trial provides the market with an indication of the efficacy of the MSCs produced by the company’s unique and scalable Cymerus platform.
“No other company in the world has the capability to produce MSCs at an equivalent commercial scale without requiring multiple donors,” he said.
“We are focused on proving the broad applicability of Cymerus-produced MSCs.
“Successful preclinical and clinical results pave the way for us to leverage our technology platform across multiple disease target areas and provide significant opportunities for monetisation and commercial partnerships,” Dr Macdonald added.
He noted that steroid-resistant GvHD was a “horrific disease” that causes “debilitating symptoms” and a “very high rate of mortality”.
“We are delighted to see such positive outcomes among participants in cohort A and we look forward to completing [the trial] of cohort B and evaluating the initial safety and efficacy of a higher dose level of CYP-001,” Dr Macdonald said.
By late afternoon trade, Cynata’s share price had risen more than 6% to A$1.405.