Early data from an ongoing clinical trial led by Jefferson Health gives hope that there may soon be a minimally invasive treatment for loss of smell and taste.
Researchers have developed a topical treatment that uses platelet-rich plasma to restore the senses.
Loss of smell and taste – known as anosmia – is a common symptom of COVID-19. Although most people infected with the coronavirus disappear, up to 1.5 million U.S. residents continue to have long-term smell and taste disturbances, the researchers said.
Nancy A. Damato, one of the study participants, said losing her sense of smell and taste to COVID was “life changing.”
“I felt like I was missing a part of myself and more than anything, I missed the experience of getting together as a family to enjoy a meal,” she said. “Fortunately, the treatments provided by Thomas Jefferson University Hospital are improving my symptoms and showing signs of progress. For the first time in a long time, I have hope of returning to a normal life.”
Platelet-rich plasma, or PRP, can regenerate cells and heal tissue. It has become a commonly used restorative therapy to treat injured muscles and tendons, increase hair growth, and reduce the appearance of scars.
Animal studies have shown that PRP can also regenerate cells in the olfactory epithelium – a thin cell tissue inside the nasal cavity. This tissue is thought to be the site affected by COVID-19-related loss of smell. And since smell and taste are closely linked, we hope that the treatment will also improve the sense of taste.
A few small clinical trials have tested nasal injectable PRP for loss of smell. Although the results were promising, participants found the injections uncomfortable and invasive.
Topical PRP from Jefferson Health is considered a less invasive option. The PRP is mixed with a dissolving sponge and applied to the olfactory nerve in the nose via an endoscope. It is a painless procedure.
In a phase I trial, eight patients who had at least six months of olfactory disturbance received monthly applications of topical PRP for at least three months. Preliminary results show that 50% of participants experienced significant improvements in smell and taste.
The new treatment has also been provided to other patients independent of the trial with equally promising results.
In a phase II study, researchers plan to exclusively examine patients who developed long-term loss of taste and smell after COVID-19 infection. This will help them better understand patient variables and the number of treatments needed to make the most significant improvement.
“It was very important for me and our team to explore less invasive options as this issue has become more and more prevalent due to COVID-19,” said Dr. David Rosen, otolaryngologist at the Thomas Jefferson University Hospital. “The results of the Phase I clinical trial have been promising and we look forward to Phase II to further improve the treatment.”
The treatment is not covered by insurance and costs $500 per request, but will be available free of charge to patients enrolled in the next phase of the clinical study.