US-based biotechnology firm Celltex Therapeutics has secured approval from the US Food and Drug Administration (FDA) to assess autologous adipose tissue-derived mesenchymal stem cells (AdMSCs) as a prophylactic for Covid-19.

The company uses its own technology to isolate, cryopreserve and grow autologous MSCs for therapeutic use at its facility in Houston, US.

During the multi-centre, randomised, double-blind, placebo-controlled Phase II trial, AdMSCs will be assessed for their safety and prophylactic efficacy against Covid-19.

The study will enrol 200 volunteers who have never had Covid-19. Participants will be given three doses of intravenous infusions of 200 million autologous AdMSCs or placebo every three days.

The primary objective of the trial is overall safety of the MSCs while the secondary objective is the efficacy of the therapeutic as a prophylactic for people at a high risk of contracting the novel coronavirus.

The Phase II trial is expected to be completed in August next year, with early data anticipated next month.

Previously, the company performed a pilot study of its AdMSCs in five subjects.

Celltex Therapeutics chairman and CEO David Eller said: “The FDA’s approval of our IND is not only a critical milestone for Celltex, but also for everyone who has been affected by Covid-19.

“Throughout the entire pandemic, MSCs have shown promise for combatting symptoms and complications associated with Covid-19, and as the nation’s leading commercial MSC banking and technology company, Celltex has the unique ability to transition these initial findings into a clinical trial.”

In May this year, Australia-based Cynata Therapeutics received ethics committee approval to conduct a clinical trial of its Cymerus mesenchymal stem cells (MSCs) to treat adult Covid-19 patients admitted to intensive care.