, Jeremy B. Green, MD, said at the virtual annual meeting of the American Academy of Dermatology.
When the study is completed, conclusions can be reached about the investigational product’s durability of benefit for treatment of dynamic forehead lines, which are notoriously challenging to treat. However, much is already known about the product’s durability for treatment of glabellar lines, as demonstrated in SAKURA 1 and SAKURA 2, two pivotal, phase 3, multicenter, randomized, double-blind, placebo-controlled trials totaling 609 patients.
In SAKURA 1 and 2, glabellar line severity didn’t return to baseline until a median of 28 and 26 weeks after injection. In contrast, as the study authors noted, the majority of patients whose glabellar lines are treated with the currently available botulinum toxin type A products are no longer responders by 3-4 months after treatment. Since surveys indicate most patients receive repeated injections every 5-6 months, that means they’re walking around with suboptimal results for the last 2-3 months before their next treatment session (Plast Reconstr Surg. 2020 Jan;145[1]:45-58).
This investigational neuromodulator, known as DaxibotulinumtoxinA for Injection, or DAXI, is composed of a highly purified 150-KDa botulinum toxin type A coupled with a proprietary stabilizing peptide. The product is formulated without human serum albumin and, once reconstituted, is stable at room temperature.
Dr. Green, a dermatologist in private practice in Coral Gables, Fla., reported on 61 participants in the phase 2 study, all with moderate or severe forehead lines and glabellar lines as assessed by both investigators and patients on structured scales. The patients’ glabellar lines were treated with 40 U of DAXI at baseline. Then 2 weeks later, their dynamic forehead lines were treated with either 12 U, 18 U, 24 U, or 30 U of DAXI. This sequential treatment recapitulates the approach widely used in clinical practice, he noted.
At baseline, two-thirds of patients had severe forehead lines at maximum eyebrow elevation as determined by Investigator Global Assessment – Forehead Wrinkle Severity and Patient Forehead Wrinkle Severity. The other third of participants had moderate forehead lines.
The primary endpoint was the presence of no or mild forehead lines by investigator assessment 4 weeks after treatment. This was achieved in 86% of patients who received 12 U of DAXI, 87% who recieved 18 U, 94% who received 24 U, and 100% of those who received 30 U.
“There appears to be a dose-dependent response, but this hasn’t yet been statistically analyzed,” Dr. Green said.
By patient assessment, there were no or only mild forehead lines at 4 weeks in 57% of those who received the lowest dose of DAXI, with rates of 80%, 100%, and 93% in those who received 18 U, 24 U, and 30 U.
At week 4, 57% of patients who got 12 U of DAXI pronounced themselves “satisfied” or “very satisfied” with DAXI therapy, as did 73%, 100%, and 93% of those who got the higher doses.
The treatment-related adverse events consisted of a smattering of cases of edema, erythema, or headache, similar to what’s described in the product labeling of all the neuromodulators.
Revance Therapeutics has applied to the Food and Drug Administration for marketing approval of DAXI for the treatment of glabellar lines. A regulatory decision is expected in late November. The company is also developing DAXI for the treatment of variety of neurologic and musculoskeletal conditions, including poststroke upper limb spasticity.
In an interview, Dr. Green said he was favorably impressed with DAXI’s durability for amelioration of forehead lines in the patients he personally treated in the ongoing phase 2 study, although there was no head-to-head comparison with other neuromodulators in the trial. He’s not aware of any planned phase 3 trial aimed at obtaining a forehead line indication.
“Of course, all four of the neuromodulators currently approved in the U.S. have glabellar line indications, but all are also used off-label in other locations, so I would imagine that DAXI will be used similarly if and when it is FDA-approved,” the dermatologist added.
He reported serving as a paid investigator for Revance.