Pharmacotherapy of regional melanoma therapy

Targeting N-cadherin increases vascular permeability and differentially activates AKT in melanoma

OBJECTIVE

We investigate the mechanism through which N-cadherin disruption alters the effectiveness of regional chemotherapy for locally advanced melanoma.

BACKGROUND

N-cadherin antagonism during regional chemotherapy has demonstrated variable treatment effects.

METHODS

Isolated limb infusion (ILI) with melphalan (LPAM) or temozolomide (TMZ) was performed on rats bearing melanoma xenografts after systemic administration of the N-cadherin antagonist, ADH-1, or saline. Permeability studies were performed using Evans blue dye as the infusate, and interstitial fluid pressure was measured. Immunohistochemistry of LPAM-DNA adducts and damage was performed as surrogates for LPAM and TMZ delivery. Tumor signaling was studied by Western blotting and reverse-phase protein array analysis.

RESULTS

Systemic ADH-1 was associated with increased growth and activation of the PI3K (phosphatidylinositol-3 kinase)-AKT pathway in A375 but not DM443 xenografts. ADH-1 in combination with LPAM ILI improved antitumor responses compared with LPAM alone in both cell lines. Combination of ADH-1 with TMZ ILI did not improve tumor response in A375 tumors. ADH-1 increased vascular permeability without effecting tumor interstitial fluid pressure, leading to increased delivery of LPAM but not TMZ.

CONCLUSIONS

ADH-1 improved responses to regional LPAM but had variable effects on tumors regionally treated with TMZ. N-cadherin-targeting agents may lead to differential effects on the AKT signaling axis that can augment growth of some tumors. The vascular targeting actions of N-cadherin antagonism may not augment some regionally delivered alkylating agents, leading to a net increase in tumor size with this type of combination treatment strategy.

Isolated limb infusion as a model to test new agents to treat metastatic melanoma

The limb model of in-transit disease can expand our understanding of treating melanoma because of the ease of obtaining tissue biopsies for correlative studies and the availability of preclinical animal models that allow validation of novel therapeutic strategies. This review will focus on regional therapy for in-transit melanoma as a platform to investigate novel therapeutic approaches to improve regional disease control, and help us develop insights to more rationally design systemic therapy trials.

Minimally invasive intra-arterial regional therapy for metastatic melanoma: isolated limb infusion and percutaneous hepatic perfusion

INTRODUCTION

In-transit melanoma or melanoma presenting as unresectable liver metastases are clinical situations with limited therapeutic options. Regional intra-arterial therapies provide efficacious treatment alternatives for these patients. Through surgical techniques of vascular isolation, regional therapies deliver high-dose chemotherapy to tumor cells while minimizing systemic exposure. However, percutaneous techniques such as isolated limb infusion (ILI) and percutaneous hepatic perfusion (PHP) have been developed, which provide a minimally invasive means of obtaining vascular isolation of target organs.

AREAS COVERED

Areas covered in this review include the techniques of ILI and PHP, the chemotherapeutic agents utilized during these regional therapies and the clinical responses seen after ILI and PHP. The pharmacokinetics of regional chemotherapy utilized during ILI and PHP is also reviewed with an additional focus on novel ways to optimize drug delivery to improve response rates and attempts to define the potential systemic manifestations of regional therapeutics.

EXPERT OPINION

Unresectable hepatic and limb in-transit metastases from melanoma are very difficult to treat. Systemic chemotherapy has largely been ineffective. Both the minimally invasive, percutaneous techniques of ILI and PHP are excellent methods used to deliver extremely high-dose chemotherapy regionally to patients harboring metastatic melanoma confined to an extremity or liver, respectively. Studies, from prospectively maintained databases as well as Phase II and III trials, have shown the great efficacy of these techniques.

Results of isolated lower limb perfusion for loco-regional advanced/recurrent melanoma using borderline true hyperthermia plus additional bolus of melphalan. A critical analysis of homogeneous cases

BACKGROUND AND OBJECTIVE

This study was conducted to assess the safety and efficacy of our modified ILP treatment with borderline true hyperthermia and high melphalan concentration in stage III lower limb melanoma.

METHODS

Between March 1990 and December 2006, 91 consecutive patients were given ILP treatment. Forty three patients were treated with double L-PAM bolus combined with D-actinomicin; 48 patients were treated with additional L-PAM bolus alone.

RESULTS

The mean follow-up period is 68.5 months. The acute regional toxicity occurred with grade II (54%), III (38%), IV (2.1%). The systemic toxic effects were present with transitory hematological disorders. Complete response (CR) rate was observed in 89.2% of stage IIIA-IIIAB unexcised IT-mets. The overall limb recurrent disease in stage III was 39%. In patients with CR recurrent rate occurred in 44% with a mean limb recurrence-free interval (LRFI) of 23.8 months. Distant metastases was attained with a mean time of 29.2 months. After CR, the interval was 32.1 months. The 5-year survival rate was 45%; in patients with CR, was 48%.

CONCLUSIONS

Our procedure is an important therapeutic option. The results suggest a marked local control of the recurrent disease. The LRFI is longer than for those treated with other treatment schedules.