Regression of a cutaneous melanoma metastasis after intralesional cidofovir

Cutaneous Applications of the Antiviral Drug Cidofovir: A Review

Background/Objectives: Cidofovir, an antiviral drug approved for cytomegalovirus retinitis, has emerged as an alternative treatment option for virally induced cutaneous and mucocutaneous conditions, as well as being trialed as a treatment for select neoplasms. In this review, we highlight the existing evidence, clinical uses, and rationale of using cidofovir for the treatment of cutaneous pathologies. Methods: A PubMed database literature search was conducted to identify relevant articles for inclusion in this review. Results: Cidofovir has several cutaneous applications in various formulations including intravenous, topical, and subcutaneous administrations. Primarily through case reports, case series, and retrospective reviews, cidofovir has demonstrated efficacy in treating a variety of virally induced conditions-verruca vulgaris, herpes simplex virus, molluscum contagiosum-as well as in adjuvant treatment for select neoplasms. The drug has shown efficacy in immunocompromised and immunocompetent adults and children alike. Conclusions: The body of literature supports the use of cidofovir as an effective and well-tolerated treatment for many viral cutaneous pathologies, and encourages further study for its use as an adjuvant therapy for neoplastic disease.

The broad-spectrum anti-DNA virus agent cidofovir inhibits lung metastasis of virus-independent, FGF2-driven tumors

The FDA-approved anti-DNA virus agent cidofovir (CDV) is being evaluated in phase II/III clinical trials for the treatment of human papillomavirus (HPV)-associated tumors. However, previous observations had shown that CDV also inhibits the growth of vascular tumors induced by fibroblast growth factor-2 (FGF2)-transformed FGF2-T-MAE cells. Here, we demonstrate that CDV inhibits metastasis induced by FGF2-driven, virus-independent tumor cells. Pre-treatment of luciferase-expressing FGF2-T-MAE cells with CDV reduced single cell survival and anchorage-independent growth in vitro and lung metastasis formation upon intravenous inoculation into SCID mice. This occurred in the absence of any effect on homing of FGF2-T-MAE cells to the lungs and on the growth of subconfluent cell cultures or subcutaneous tumors in mice. Accordingly, CDV protected against lung metastasis when given systemically after tumor cell injection. Lung metastases in CDV-treated mice showed reduced Ki67 expression and increased nuclear accumulation of p53, indicating that CDV inhibits metastasis by affecting single cell survival properties. The anti-metastatic potential of CDV was confirmed on B16-F10 melanoma cells, both in zebrafish embryos and mice. These findings suggest that CDV may have therapeutic potential as an anti-metastatic agent and warrants further study to select those tumor types that are most likely to benefit from CDV therapy.

Microinvasive melanoma: cutaneous pharmacotherapeutic approaches

Surgical excision is the treatment of choice for primary melanomas and radiation therapy is the accepted alternative for the subset of lesions not amenable to surgery. With the recent rise in melanoma incidence, especially in the elderly, there are a growing number of cases that are neither amenable to surgery nor radiation therapy. In this article, we review pharmacotherapeutic approaches to microinvasive melanoma (invasive radial growth phase melanoma) that might be considered in such circumstances. There are no approved drugs for the treatment of primary melanoma and randomized controlled trials with 5 or more years of follow-up have not been performed. The limited studies and numerous case series in the literature on pharmacologic treatment of primary melanoma have focused on topical therapies. Accordingly, we provide a review of the potential pharmacotherapeutic agents in the treatment of microinvasive melanoma by extrapolating from the available limited literature on the use of fluorouracil, azelaic acid, retinoic acid derivatives, interferon (IFN)-α, imiquimod, and other agents for melanoma in situ, invasive melanoma, and epidermotropic melanoma metastases. Our review indicates that topical fluorouracil and tretinoin are not effective as single agents. The efficacy of azelaic acid, tazarotene, cidofovir, and intralesional IFN-α, interleukin-2, and IFN-β is undefined. Imiquimod is the most studied and promising agent; however, optimal dosage, therapeutic regimen, and survival rates are unknown. In the face of a growing demand for non-surgical treatments, formal clinical trials are needed to ascertain the role of pharmacotherapeutic agents in the treatment of microinvasive melanoma.

Intralesional agents in the management of cutaneous malignancy: a review

Intralesional agents have a role in the management of cutaneous malignancies. In this article, the efficacy, side effects, strengths, limitations, costs, and practical considerations regarding the use of intralesional agents to treat basal cell carcinoma, squamous cell carcinoma, selected cutaneous lymphomas, and even metastatic melanoma are reviewed. Intralesional administration of 5-fluorouracil, interferon, interleukin-2, bleomycin with electrochemotherapy, and aminolevulinic acid with photodynamic therapy are discussed as treatment modalities in basal cell carcinoma. Interferon (∼1.5 M IU, 3 times weekly × 3 weeks) is perhaps the most widely used regimen for basal cell carcinoma. With regard to squamous cell carcinoma, treatment with 5-fluorouracil, methotrexate, interferon, and bleomycin are reviewed. Methotrexate (∼0.3-2.0 mL of 12.5 or 25 mg/mL, two injections ∼2 weeks apart) was perhaps the most widely used agent. Interferon (3 M IU × 3 times weekly for ∼8.5 weeks) and rituximab (10-30 mg per lesion, 3 times weekly for 1 week, possibly repeated 4 weeks later) are sometimes used in the management of primary cutaneous B-cell lymphomas, whereas in primary cutaneous CD30(+) lymphoma intralesional methotrexate (0.4-0.5 mL of 50 mg/mL weekly for 2 weeks) has been used. Finally, the roles of BCG vaccine, cidofovir, rose bengal, and bleomycin with electrochemotherapy for the palliation of metastatic melanoma are reviewed. Intralesional management appears most useful when surgical intervention is not a viable option, for cases in which the cosmetic outcome may be superior, or for situations in which the side effects from systemic chemotherapeutic agents are to be minimized.