Sitavig® (50mg acyclovir) Muco-Adhesive Buccal Tablet is a new treatment option for recurrent herpes labialis, offering a unique vehicle and delivery system. Sitavig, licensed to Innocutis by BioAlliance Pharma, uses proprietary Lauriad® delivery technology, which delivers a high and sustained concentration of acyclovir in saliva and labial mucosa. An 8mm in diameter, 2.2-2.6m thick tablet adheres to the gum, above the canine tooth on the side of the lip that is infected with a cold sore. The tasteless, odorless tablet dissolves in 4 to 6 hours to provide a sustained release of acyclovir.
Phase III study results demonstrate that a single low dose of Sitavig acyclovir buccal tablet improved all clinical parameters of herpes labialis. The incidence of blocked herpes episodes was increased by 24.2% (34.9% vs 28.1%; p = 0.042) in the active treatment group. During the nine-month follow up, recurrence of herpes lesions was less frequent (64.2% vs 73.6%; p = 0.027) and delayed (205 days vs 165 days, p = 0.041) in the Sitavig 50mg group compared to placebo controls.
Reduction in frequency of and time to recurrence “may be due to the rapid and high acyclovir concentrations in the basal layer of the mucosa where HSV-1 replication is most abundant ,” suggests Christopher Downing, MD, Sub-Investigator at the Center for Clinical Studies in Houston, TX.
The new formulation may provide benefits in terms of both compliance and drug delivery, according to investigators. Therapeutic adherence is a concern with topical formulations of acyclovir. “They have to be reapplied multiple times, and reapplication may become less frequent over time,” says Dr. Downing. “This new formulation is quite innovative. It is applied to the gum just one time.”
“Patients using the product are, by definition, compliant,” adds Stephen K. Tyring, MD, PhD, clinical professor of dermatology at the University of Texas Health Science Center in Houston, Texas. “Either patients are 100% compliant or they are not compliant at all.”
Drs. Downing and Tyring participated in trials for Sitavig. Data have been published in Journal of Drugs in Dermatology. The majority of subjects in the clinical trial had previously used acyclovir, and it was necessary to stress that they were not to swallow the tablet. It was an easy concept to explain, Dr. Tyring says, and patients easily applied the tablet as instructed. He adds that if a patient does swallow a tablet, there is no associated safety concern.
In a multicenter double blind placebo-controlled patient-initiated trial, 775 patients with recurrent HL were randomly assigned to either a single application of Sitavig 50mg or matching placebo as soon as prodromal symptoms occurred.
“This treatment is best suited for the patient who can recognize prodromal symptoms of disease and apply the treatment as quickly as possible once the syndrome is identified,” Dr. Downing says. Patients can be advised to have their prescription with them when going to the beach or ski slopes or other locations that are associated with inducing HSV flares.
Although the study did not investigate subjects who applied Sitavig during an active outbreak, Dr. Tyring believes treatment may provide benefit to patients with active herpes labialis. Furthrmore, there is no reason the formulation cannot be used in combination with standard interventions for symptom management.
Local and overall tolerance of Sitavig 50mg was acceptable in the trials. Application site irritation was slight and infrequent (<1%).