Smell and taste disturbances — or anosmia and parosmia — are common symptoms of COVID-19. And now, thanks to a team of physicians and researchers at Thomas Jefferson University Hospital, a minimally invasive treatment may soon offer relief.

Led by otolaryngologist Dr. David Rosen, the team has developed a first-of-its-kind topical platelet-rich plasma (PRP) treatment, according to an announcement from the hospital. Preliminary results from an ongoing clinical trial show promise in restoring patients’ sense of smell and taste, it stated.

PRP is a common restorative therapy used to regenerate cells, heal tissue and address medical conditions such as injured muscles and tendons, hair loss and scars. The hospital said animal studies have shown that PRP helps regenerate the olfactory epithelium, which may be the site affected in COVID-19 induced olfactory dysfunction. Until now, PRP has been used as a sometimes “uncomfortable and invasive” nasal injectable in several small clinical trials for smell loss.

“I’ve dedicated over two decades to helping patients recover from the loss of taste and smell,” Rosen said in a statement. “It was very important to me and our team to explore less invasive options as this issue has become increasingly prevalent due to COVID-19.”

The new topical PRP treatment consists of monthly applications for a minimum of three months. A recent phase I clinical trial of eight patients who had at least six months of olfactory disturbance has shown preliminary success with 50% of participants experiencing clinically significant improvements in smell and taste.

The hospital said it was largest pilot study to date for the use of PRP in treatment of OD and the first study to develop methods for topical delivery in human subjects.

A planned phase II study aims to look at patients who developed long-term olfactory disturbance following recovery from COVID-19. The treatment is currently not covered by insurance and costs $500 per application, but will be available to patients in the next phase of the study for free.

“The widespread smell dysfunction that accompanied the COVID-19 virus has raised awareness of the many ways in which smell loss impacts health and well-being on a daily basis,” added Dr. Pamela Dalton, Monell Chemical Senses Center, an independent nonprofit institute at the University City Science Center campus in Philadelphia. “The promising results from this study bring hopeful news to the many individuals who continue to experience persistent post-viral smell loss.”