German-based drug-development company AiCuris Anti-infective Cures has reported positive results from its phase I trial of pritelivir for the topical treatment of recurrent labial herpes (cold sores).
Derived from the chemical class (thiazolylamides), pritelivir is a highly active, small molecule, helicase-primase inhibitor of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2).
Pritelivir prevents the de novo synthesis of virus DNA by inhibiting the helicase-primase complex.
The randomised, single-centre, controlled, within-subject comparison phase I trial (AIC316-02-I-01) was designed to assess the local cumulative irritation potential of topical pritelivir when applied on normal human skin in 46 male and female healthy volunteers under occlusive conditions.
Each volunteer was administered with 5% of pritelivir ointment on a daily basis in conjunction with three controls for 21 days on the back.
The controls were the vehicle ointment without pritelivir, with saline as a negative control and 0.2% sodium lauryl sulfate (SLS) as a positive control.
The application areas were tested on a daily basis in a blinded manner to detect dermal reactions using a visual skin irritation scoring system to rate the degree of erythema, edema and other signs of skin irritation.
Results suggested that pritelivir did not exhibit any cumulative irritation potential, thereby achieving the primary goal of the study.
AiCuris Anti-infective Cures CEO Dr Holger Zimmermann said: “These phase I results, coupled with the preclinical results we have seen with topical pritelivir, are highly promising and strongly support the further development of topical pritelivir for recurrent labial herpes.
“There remains a major unmet medical need to treat HSV-1 infections, such as labial herpes, as there are very few specific antivirals available and available topical treatments are often ineffective.
“Topical pritelivir, if proven safe and effective in further clinical testing, could be an important new treatment option for this very painful condition.”
Pritelivir has also demonstrated its efficacy when compared with the standard treatment of valacyclovir for genital HSV-2 infection in a Phase II clinical trial.
Image: Micrograph displaying herpes simplex virus. Photo: courtesy of CDC/Dr. Erskine Palmer.