Sorafenib, a multikinase inhibitor, enhances the response of melanoma to regional chemotherapy

Melanoma responds poorly to standard chemotherapy due to its intrinsic chemoresistance. Multiple genetic and molecular defects, including an activating mutation in the BRaf kinase gene, are associated with melanoma, and the resulting alterations in signal transduction pathways regulating proliferation and apoptosis are thought to contribute to its chemoresistance. Sorafenib, a multikinase inhibitor that targets BRaf kinase, is Food and Drug Administration approved for use in advanced renal cell and hepatocellular carcinomas. Although sorafenib has shown little promise as a single agent in melanoma patients, recent clinical trials suggest that, when combined with chemotherapy, it may have more benefit. We evaluated the ability of sorafenib to augment the cytotoxic effects of melphalan, a regional chemotherapeutic agent, and temozolomide, used in systemic and regional treatment of melanoma, on a panel of 24 human melanoma-derived cell lines and in an animal model of melanoma. Marked differences in response to 10 micromol/L sorafenib alone were observed in vitro across cell lines. Response to sorafenib significantly correlated with extracellular signal-regulated kinase (ERK) downregulation and loss of Mcl-1 expression (P < 0.05). Experiments with the mitogen-activated protein kinase/ERK kinase inhibitor U0126 suggest a unique role for ERK downregulation in the observed effects. Sorafenib in combination with melphalan or temozolomide led to significantly improved responses in vitro (P < 0.05). In the animal model of melanoma, sorafenib in combination with regional melphalan or regional temozolomide was more effective than either treatment alone in slowing tumor growth. These results show that sorafenib in combination with chemotherapy provides a novel approach to enhance chemotherapeutic efficacy in the regional treatment of in-transit melanoma.

Cadherins as novel targets for anti-cancer therapy

The cell adhesion molecules N-, VE- and OB-cadherin have been implicated as regulators of tumor growth and metastasis. We discuss evidence that N- and VE-cadherin play a key role in promoting blood vessel formation and stability, processes which are essential for tumor growth. Secondly, we describe the potential involvement of N- and OB-cadherin in the metastatic process. Finally, studies concerning the effects of the N-cadherin antagonist designated ADH-1 on tumor growth are presented. Collectively, these observations suggest that antagonists of N-, VE- and OB-cadherin would be useful as anti-cancer agents.

Optimizing melphalan pharmacokinetics in regional melanoma therapy: does correcting for ideal body weight alter regional response or toxicity?

BACKGROUND

This study aims to determine what effect correcting melphalan dosing for ideal body weight (IBW) has on toxicity and response in isolated limb infusion (ILI) in patients with advanced extremity melanoma.

METHODS

This was an open observational study examining whether correcting the melphalan dose for IBW will influence response and toxicity in patients undergoing ILI for advanced extremity melanoma in 41 patients undergoing 42 procedures (13 without correction for IBW; and 29 with correction for IBW). Melphalan pharmacokinetics, limb toxicity, serologic toxicity, and response at 3 months were compared.

RESULTS

The corrected group had a lower estimated limb volume (V (esti)) to melphalan volume at steady state (V (ss)) (P < .0001) ratio as well as lower incidence of grade > or =3 regional toxicity, serologic toxicity, and compartment syndrome (P = .0249, P = .027, P = .02). There was a positive correlation of V (esti)/V (ss) to toxicity (P = .0127, r = .382). No significant difference in response (P = .3609) between the groups was found, although there was a trend of association between V (esti)/V (ss) and response (P = .051, r = .3383).

CONCLUSIONS

Correcting for IBW in ILI lowers toxicity without significantly altering response rates.