Tirbanibulin Ointment Clears Actinic Keratosis Lesions in Half of Recipients Within 2 Months

By Gene Emery

February 11, 2021

NEW YORK (Reuters Health) - Just five treatments with an experimental ointment over five days were able to completely clear actinic keratosis lesions in half of all volunteers within two months, although one year after treatment the lesions had reappeared in many cases, according to a new clinical trial.

The lesions cleared in 49% of the 353 volunteers randomly assigned to use an ointment containing the Athenex drug tirbanibulin, versus 9% among the 349 patients given an identical cream withsout the drug, researchers report in the New England Journal of Medicine.

The benefit of the single treatment course, when it worked, was usually only temporary. At the one-year mark, 71% of the patients had a new or recurrent lesion.

In addition, the therapy produced some local reactions in most recipients and application-site pain in 10%, although coauthor Dr. Andrew Blauvelt said those side effects were significantly less bothersome than conventional treatments.

The cream, marketed under the brand name Klisyri, was approved for face and scalp use by the U.S. Food and Drug Administration on December 15.

The results "are right in line with the other field treatments that tend to be more irritating and induce more inflammation. In the case of this treatment, the skin reaction, the side effects are minimal to none, and that's a big difference compared to the other field therapies for this very common disease," Dr. Blauvelt, director of the private clinical trials center Oregon Medical Research Center, in Portland, told Reuters Health by phone.

A study published last year in the Journal of the American Geriatrics Society found actinic keratosis - a precursor to squamous-cell carcinoma - in 22% of 552 adults in Finland age 70 and older who received a whole-body skin examination. In the United States, about 58 million people have it.

In the new study, funded and overseen by Athenex and conducted at 62 sites in the U.S., the patients had actinic keratosis on their face or scalp, with four to eight lesions within 25 cm2.

Among the volunteers who received the drug-laced cream, partial clearance - defined as clearance of at least 75% of lesions - occurred in 72% of patients, versus 18% of volunteers in the placebo group.

Of the 174 people who initially had complete clearance, 124 had lesions reappear or appear anew in the treatment field. In 58% of those cases, the lesions reappeared and in 42% the lesions were new.

"One of the knocks against this drug had been the recurrence rate," said Dr. Blauvelt. "But if you look at all the studies done on other topical treatments available for this disease, they were done for shorter time periods and didn't have a one-year follow-up."

"But it's not uncommon to retreat the area many times over several years. So, this is typical not only for this drug but any therapy for actinic keratosis," he said. "What really this drug needs now is additional studies where you are treating longer with repeated courses."

The rates of any adverse events were 35% with tirbanibulin versus 36% with placebo.

Erythema occurred in 91% of the patients getting the cream containing the drug. Scaling was seen in 82% of cases. All of the local reactions were temporary.

The pain, seen in 10% of the recipients, tended to consist of a slight tenderness, said Dr. Blauvelt. Pruritus appeared in 9% of the volunteers getting the drug.

He said that with other products, "patients have to be out for a week, their faces get so red. They tend to have much more severe local reactions compared to this product. In our case, we were surprised how little irritation we saw."

Dr. Blauvelt reports financial ties to Athenex.

SOURCE: https://bit.ly/3roSu2Q The New England Journal of Medicine, online February 10, 2021.