SKNV Licenses Washington University Immunotherapy Patent for Fluorouracil-Calcipotriene Combination in Actinic Keratosis
Key Insights
SKNV has licensed a Washington University (search) patent portfolio covering the fluorouracil-calcipotriene combination therapy for actinic keratosis (search), moving academic immunotherapy research into commercial practice through the compounding market.
The American Academy of Dermatology has updated its guidance to favor field-directed therapy over lesion-by-lesion treatment, with the combination central to this shift due to its potential to reduce progression to squamous cell carcinoma (search).
Published data in the Journal of Clinical Investigation showed the combination reduced AK lesion counts after just four days of treatment, compared to the two-to-four-week course required for fluorouracil monotherapy.
SKNV has licensed a Washington University (search) patent portfolio covering the fluorouracil-calcipotriene combination, a regimen increasingly recognized as one of the most promising field therapies for actinic keratosis (search) (AK). The deal moves academic work on tissue-resident anti-tumor immunity into commercial practice through the compounding market. No financial terms were disclosed.
The licensing agreement arrives as the American Academy of Dermatology has updated its guidance to favor field-directed therapy for actinic keratosis (search) over lesion-by-lesion treatment, citing the approach's potential to reduce progression to squamous cell carcinoma (search). The fluorouracil-calcipotriene combination is central to that shift: in April 2026, the International Immunosuppression and Transplant Skin Cancer Collaborative recommended a short course of the combination for AK management, based largely on data generated by the Washington University (search) and Massachusetts General Hospital researchers who hold the underlying patents.
Mechanism of Action: Two Established Agents, One Immunological Approach
The combination pairs two long-approved single agents rather than introducing a new molecular entity. Fluorouracil, a cytotoxic antimetabolite, triggers immunogenic cell death and tumor-antigen release from sun-damaged keratinocytes. Calcipotriene, a vitamin D receptor (search) agonist, drives thymic stromal lymphopoietin (search)-mediated CD4 (search)+ T-cell infiltration into treated skin. Together, the two agents generate a robust, tissue-resident anti-tumor immune response that extends well beyond the treatment period.
Washington University (search)'s Lynn Cornelius and Massachusetts General Hospital's Shawn Demehri, co-inventors on the underlying intellectual property, published data in the Journal of Clinical Investigation demonstrating that the combination reduced AK lesion counts after just four days of treatment, versus the two-to-four-week course typically required for fluorouracil monotherapy.
Long-Term Protection Against Squamous Cell Carcinoma (search)
A follow-up study tracking the same trial cohort for more than 1,500 days linked the short course to reduced squamous cell carcinoma (search) incidence on treated face and scalp sites. The researchers associated this durable protective effect with the persistence of tissue-resident memory T cells, suggesting that the combination therapy induces lasting immunological surveillance in treated skin.
Commercial Pathway Through 503B Outsourcing
Unlike an FDA-approved combination product, the therapy — branded as Kefunova — is supplied through SKNV's FDA-registered 503B outsourcing facility. This regulatory pathway allows commercialization without a separate New Drug Application (NDA) but limits the labeling claims the company can make. The 503B structure carries lower regulatory barriers but a correspondingly narrower commercial ceiling than an approved fixed-dose product would command.
Ongoing Academic Development
A parallel signal underscores the continued scientific momentum behind the combination: the National Cancer Institute is funding a Phase II trial of the identical fluorouracil-calcipotriene combination in organ transplant recipients, run by the same inventor group. Continued institutional development of the asset outside SKNV's commercial license suggests the underlying science remains active even as SKNV moves to commercialize it through the compounding channel.