Sex: F
Vaccine: HPV9
Symptoms: Product administered at inappropriate site, Scar, Therapeutic response unexpected, Tumour pain
Clinical narrative: This literature marketed report was received from the authors in a published literature article, concerning an immunocompetent elderly female patient in her 90's who presented to a university-based outpatient dermatology clinic with numerous large, non tender, exophytic tumors on her right leg. Histopathologic examination demonstrated tumor islands of basaloid cells with central comedolike necrosis within a fibrotic dermis, extending from the undersurface of the epidermis. Immunohistochemical analysis results were positive for epithelial membrane antigen, negative for Ber-EP4, and strongly positive for p16, confirming the diagnosis of basaloid squamous cell carcinoma (SCC), an aggressive SCC with a high recurrence rate after Mohs micrographic surgery and a propensity to metastasize. Positron emission tomographycomputed tomography findings showed no abnormalities, eliminating the possibility that these tumors represented metastatic basaloid SCC from a distant, non cutaneous site. Mohs surgery was performed on the largest tumor, but considering the patient's advanced age and extensive tumor burden, additional surgery and radiotherapy were considered to be unfeasible. After the patient declined systemic chemotherapy, she was treated off-label GARDASIL 9 delivered systemically and then intratumorally to the largest tumors. Methods: With the oral informed consent of the patient and her son, the patient was treated with the GARDASIL 9 from 17-MAR-2016, through 27-FEB-2017, and was followed up through 21-MAY-2018. She was initially treated with 2 doses of intramuscular GARDASIL 9 administered 6 weeks apart. Three weeks after the second intramuscular dose, 3 of the largest tumors were treated intratumorally with 9-valent HPV vaccine (0.5 mL) diluted with sterile saline (2.5mL) after the tumors had been anesthetized with lidocaine, 1%, with epinephrine (1:100000). Three additional similar doses of the GARDASIL 9 were administered intratumorally during the ensuing 8 months, leading to complete resolution. No additional treatments were used. Results: Clinical improvement was observed 2 weeks after the second intratumoral dose of the GARDASIL 9 with reduction in tumor size and number. Eleven months after the first intratumoral dose, there was no clinical or histologic evidence of residual SCC. On examination, there were small violaceous scars and 1 small, pink, scaly, minimally elevated papule on her right leg at sites corresponding to previous large tumors. Histopathologic analysis of the pink, scaly papule was performed, the results of which demonstrated mild cellular atypia of basal keratinocytes with hyperkeratosis. The only adverse effect was mild pain within some of the tumors on the day of intratumoral vaccine administration. No systemic adverse effects were reported. At the patient's most recent follow-up visit, 24 months after the first intratumoral administration of the GARDASIL 9, there was no clinical evidence of SCC recurrence. The prophylactic role of GARDASIL 9 vaccination was well understood; however, the mechanisms of its therapeutic efficacy in cutaneous malignant tumors were not yet clear. The potent therapeutic benefit may reflect a combination of immunologic, antiviral, and antitumor effects of GARDASIL 9. At the time of reporting, the outcome of tumour pain was unknown. The reporter considered tumour pain to be related to GARDASIL 9. Upon internal review the tumour pain was considered as medically significant.