Aclaris Therapeutics, Inc.’s A-101 45% Topical Solution (A-101 45%), an investigational new drug, for the potential treatment of common warts, performed well in its second Phase 3 clinical trial, THWART-1 (WART-301).

A-101 45% met the primary and all secondary efficacy endpoints, achieving clinically meaningful and statistically significant clearance of common warts, the Company reports.

A-101 45% is a proprietary high-concentration hydrogen peroxide topical solution being developed as a potential prescription treatment for common warts. 

THWART-1 is the second of two Phase 3 pivotal trials: THWART-1 and THWART-2 (WART-301 and WART-302, respectively). The two randomized, double-blind, vehicle-controlled trials were designed to evaluate the efficacy and safety of A-101 45% as compared to placebo (vehicle) for the treatment of common warts when applied by subjects (or the parents/guardians of subjects < 18 years).

The THWART-1 trial randomized 503 subjects who self-administered either A-101 45% or vehicle twice a week over 8 weeks, for a total of 16 treatments. Each subject had one to six common warts at baseline. The trial achieved its primary endpoint with a high degree of statistical significance (p=0.0003), i.e. a higher proportion of subjects treated with A-101 45% versus vehicle had all their identified common warts reported as clear at day 60.  Warts were assessed using the Physician Wart Assessment™ scale which is a validated four-point scale of the investigators’ assessment of the severity of all treated common warts (PWA=0 means clear).  All secondary efficacy endpoints also achieved statistical significance in favor of A-101 45% versus vehicle.

In the THWART-1 trial, the two other secondary efficacy endpoints also achieved statistical significance in favor of A-101 45% Topical Solution versus vehicle and are described as follows:

  • Proportion of subjects with a single common wart whose wart is clear at day 60 (p=0.0009); and
  • Time for subjects to achieve clearance of all treated common warts (p<0.0001).

In THWART-1, there were no treatment-related serious adverse events (SAEs) in subjects treated with A-101 45%; however, tqo non-related treatment-emergent SAEs were reported (an animal bite in the A-101 45% group and a suicide attempt in the vehicle group).  The most common adverse events (AEs) occurring in more than 5% of subjects in the A-101 45% group were application site pain, scabbing, erythema, pruritus and erosion.  Treatment-related AEs were reported in 52.8 percent (34.6 percent mild, 17.3 percent moderate and 0.8 percent severe) and 6 percent of the subjects in the A-101 45% and vehicle groups, respectively.  No subjects withdrew because of AEs, but one subject in the A-101 45% group discontinued treatment due to application site erythema and vesicles.

The safety data from THWART-1 trial was comparable to that of the THWART-2 trial, which was previously reported in Aclaris’ September 16, 2019 press release.

“These results provide robust clinical evidence for the efficacy and safety of A-101 45% and support its viability as a potential treatment for common warts,” says Dr. David Gordon, Chief Medical Officer of Aclaris, in a news release. “These data will serve as the basis for an NDA filing, and we believe A-101 45% will be of interest to partners seeking to commercialize this drug candidate, which has the potential to be the first FDA-approved prescription treatment for common warts.”