Randomized Phase IIa Trial of Purified Candida Antigen for Common Warts: Evaluating the Safety and Efficacy Across Multiple Dosing Regimens
Year: 2025
Type: article
Study designs: Randomized Controlled Trial, Clinical Trial
Abstract: Non-standardized Candida albicans antigens are commonly used for the treatment of common warts (verruca vulgaris); however, clinical studies thus far have not determined optimal dosing. This study assessed three dosing schemes using Candin®, a standardized purified Candida antigen (PCA), for the treatment of common warts. This placebo-controlled, randomized phase IIa clinical trial included participants that had 3 to 20 injectable common warts on prespecified anatomical regions. PCA was administered intralesionally for up to 10 injections every 2 weeks, with adjustments to every 3 weeks for local tolerance issues. Three dosing regimens were evaluated: 0.3 or 0.5 mL into a single wart (cohorts 1 and 2, respectively), or 0.3 mL into up to four warts (cohort 3). Total injection volumes in cohorts 2 and 3 were larger than the typical off-label use of C. albicans. The primary outcome was complete resolution of injected warts, while secondary outcomes included safety, tolerability, and the clearance of untreated common warts. The incidence of clearance of the primary injected wart in placebo participants was 41.9%, compared to 65.9% (relative risk [RR] 1.57; 95% confidence interval [CI] 1.02, 2.42; P = 0.03) in cohort 1, 79.5% (RR 1.89; 95% CI 1.27, 2.82; P = 0.0007) in cohort 2, and 72.5% (RR 1.74; 95% CI 1.19, 2.50; P = 0.005) in cohort 3, and treatment was well tolerated. Injection of 0.5 mL PCA into a single wart also resulted in a significantly higher rate of clearance of untreated common warts compared to placebo (RR 3.2, 95% CI 1.2, 8.0, P = 0.001). All three dosing regimens of PCA were safe, well tolerated, and resulted in significantly greater clearance of the primary treated wart(s) compared to placebo, but only 0.5 mL injected into a single wart was significantly better than placebo at clearing untreated warts. Typically, a volume of 0.3 mL C. albicans antigen is injected into a single wart; however, these results suggest that a larger volume of 0.5 mL may have greater benefit for patients. A phase III clinical trial is currently underway to confirm these findings. ClinicalTrials.gov NCT02393417. Current treatments for warts, such as over-the-counter medications or freezing at a doctor’s office, are not always effective for all patients and require each wart to be treated separately. Another treatment option is injecting a wart with Candida albicans (KAN-dee-duh AL-buh-kans), a type of yeast that lives in many people’s bodies. C. albicans can stimulate a patient’s immune system to destroy not only the treated wart but sometimes even untreated warts. This treatment might be a good option for patients with warts that did not respond to common therapies. Patients with multiple warts might also benefit, since an injection into a single wart might clear others without having to treat each one with therapies that can be uncomfortable. Doctors do not yet know the best dose to use for this treatment, and many use C. albicans that is safe but not purified to US Food and Drug Administration (FDA) standards. In this study, patients with warts received one of three doses of a pure, FDA-approved version of C. albicans: (1) 0.3 mL injected in one wart, (2) 0.5 mL injected in one wart, and (3) 0.3 mL injected in up to four warts. All doses were safe and well tolerated, and all worked better than placebo (a saltwater injection) at clearing the treated warts. The 0.5-mL dose in a single wart was also better than placebo at clearing warts that were not injected, suggesting that a higher-than-usual dose might be better for patients. A larger study is underway to confirm these findings in more patients.
Source: Dermatology and Therapy
Language: English
Subfield: Dermatology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $7,400
OpenAlex ID: W4408997579