PERTH, Australia – Avita Medical Ltd. plans to submit its Recell spray-on-skin premarket approval application to the FDA in a few weeks following positive results from its pivotal trial.

The Perth-headquartered regenerative medicine company said that the 30-patient trial met both co-primary and secondary endpoints in patients with severe burns.

The pivotal study was conducted at seven U.S. burn centers between 2015 and early 2017. Co-primary endpoints were designed to demonstrate the effectiveness of Recell when combined with widely meshed (expanded) skin grafting to close deep-partial and full-thickness burn injuries. Treatment was randomly allocated to two separate parts of each patient's burn wound so that outcomes could be compared for conventional skin grafting vs. the combination of Recell with a more expanded skin graft.

The first co-primary endpoint measured superiority of donor skin expansion to see if using Recell could lead to less donor skin being needed. That difference in donor skin expansion with Recell was found to be significant (p<0.001) and resulted in using 30 percent less donor skin than the control and a commensurate reduction in donor site size.

Avita CEO Adam Kelliher told BioWorld Today that reducing donor skin is a "very important aspect because when patients have a large burn it is a matter of life or death to get the skin coverage back again, and the standard of care is to put on a skin graft harvested from elsewhere on the body. This creates another wound on the body, so if you can reduce the size of that wound, that has massive significance for the patient in terms of reducing trauma."

The second co-primary endpoint measured healing, which was similar in wounds that received Recell compared to those that received the control treatment.

Three secondary endpoints evaluated patient preference of scar outcomes along with overall opinion ratings using a standardized scar assessment scale, and no statistical difference was observed between the two treatments.

Results of the trial coincide with other positive results seen in another supportive trial, and the company said it believes approval of the Recell autologous cell harvesting device could come as early as the second quarter of 2018.

"We've shown that by combining grafting with the skin cell technique you can get a better outcome on the wound itself and reduce the amount of donor skin required," Kelliher said, noting that there have been no adverse events, and the device has been used "thousands of times."

"We're re-transporting skin cells back onto the patient," Kelliher said. "It's a very simple elegant means to address complicated problems."

Recell allows in-theater preparation of a spray-on suspension consisting of cells derived from a small (2x2 cm), thin (0.15 mm to 0.20 mm) biopsy of a patient's own skin that is sufficient to cover an area up to 80 times the size of the biopsy. The Recell suspension contains basal keratinocytes, melanocytes, fibroblasts and Langerhans cells. The metabolically responsive epithelial cells migrate across the wound surface, leading to regeneration of skin of normal color and texture. Recell requires a minimal donor site and is immediately available as a cell-based spray at the patient's bedside.

The procedure itself is a four-step process that involves taking a skin sample, and introducing the cells to the Recell device that incubates the skin with certain enzymes to soften the skin and loosen the cells. The cells then search for other cells and create "islands of healing across the wound bed."

"Submission of the PMA, and FDA approval, will be the final steps on a long road to improve burn care," said James Holmes, from Wake Forest Medical Center, North Carolina, who led the pivotal trial.

The spray-on-skin product was originally invented in Western Australia. It was first used in 2002 to heal burn victims of the Bali terrorist attack who were flown to Royal Perth Hospital and treated by Fiona Wood, the co-inventor of the spray-on-skin.

The pivotal trial was supported by the Biomedical Advanced Research and Development Authority (BARDA) via a $61.9 million contract. The successful completion of the trial is a major Avita milestone under the BARDA contract supporting the Department of Health and Human Services' mission toward burn care preparedness in the response to a mass casualty event.

Recell is available in the U.K., Germany, Australia and New Zealand and globally via distributors in France, Belgium, Netherlands, Turkey, China, Malaysia, Taiwan, Iran and South Africa.