3. Shortcomings of Current Melanoma Therapies Overall, melanoma incidence has been increasing over the years, reaching an annually increase of 3.1% during the past two decades . Early prognosis permits 90% survival rates by surgical removal. Yet,
unresectable advanced melanoma is characterized by an aggressive behaviour, fast spread and Inhibitors,research,lifescience,medical metastasis, and a strong resistance to chemotherapy. Therefore, and in spite of the extensive research, the current prognosis for patients with advanced melanoma is limited. The earlier conventional chemotherapeutic treatment approved by US Food and Drug Administration (FDA), Dacarbazine, results in less than 10% response rate with median response durations of 4–8 months . Alternative chemotherapeutic agents include Fotemustine, Temozolomide, NF-��B inhibitor library Paclitaxel (often in combination with carboplatin), and Docetaxel —all not yielding larger progression-free Inhibitors,research,lifescience,medical survival (PFS) or overall survival (OS) than Dacarbazine [50, 51]. Generally, chemotherapeutics suffer from a lack of targeting Inhibitors,research,lifescience,medical specificity; their low molecular mass results in easy and fast
body secretion, and thus the need of increased doses, which leads to inevitable toxicity. Similarly, immunotherapy based on interleukine 2 (IL-2)—also FDA approved—has comparable response rates, and it is further restricted by the ensuing multiorgan toxicity, requiring management in specialized cancer centers. Inhibitors,research,lifescience,medical Although combined therapies resulted in higher response rates, they still failed to translate into improved survival, with no impact on PFS or OS compared to Dacarbazine alone [1, 52]. Another alternative is the combined treatment with the cytokine TNFα in combination with the alkylating drug melphalan. Although highly successful, this treatment is limited to local treatment of melanoma in-transit metastases in limbs by isolated limb perfusion due to live threatening systemic toxicity of therapeutically Inhibitors,research,lifescience,medical active TNFα doses . In the last
decade, much progress was achieved due to the discovery of mutations in the BRAF gene. This led to the development of therapies interfering with RAS/RAF signaling and to specific BRAF inhibitors. In August 2011, an alternative melanoma regimen, for patients positive for BRAF mutations, was brought into the market with the FDA approval of Vemurafenib (Zelboraf, Plexxikon/Roche). In Phase II and III studies, Vemurafenib Sclareol showed a response rate up to 50%, yet the response duration varied between the phase studies [54–56]. In addition, Vemurafenib induces acanthopapillomas, keratoacanthomas, and cutaneous squamous cell carcinomas in the early treatment [57, 58]. Unfortunately, these unprecedented response rates are limited by the fact that almost all tumors become resistant to this therapy and the overall survival of patients was 6.7 months .