Purpose: Isolated limb infusion (ILI) with melphalan (M-ILI) dosing corrected for ideal body weight (IBW) is a well-tolerated treatment for patients with in-transit melanoma with a 29% complete response rate. ADH-1 is a cyclic pentapeptide that disrupts N-cadherin adhesion complexes. In a preclinical animal model, systemic ADH-1 given with regional melphalan demonstrated synergistic antitumor activity, and in a phase I trial with M-ILI it had minimal toxicity.
Patients and methods: Patients with American Joint Committee on Cancer (AJCC) stage IIIB or IIIC extremity melanoma were treated with 4,000 mg of ADH-1, administered systemically on days 1 and 8, and with M-ILI corrected for IBW on day 1. Drug pharmacokinetics and N-cadherin immunohistochemical staining were performed on pretreatment tumor. The primary end point was response at 12 weeks determined by Response Evaluation Criteria in Solid Tumors (RECIST) criteria.
Results: In all, 45 patients were enrolled over 15 months at four institutions. In-field responses included 17 patients with complete responses (CRs; 38%), 10 with partial responses (22%), six with stable disease (13%), eight with progressive disease (18%), and four (9%) who were not evaluable. Median duration of in-field response among the 17 CRs was 5 months, and median time to in-field progression among 41 evaluable patients was 4.6 months (95% CI, 4.0 to 7.1 months). N-cadherin was detected in 20 (69%) of 29 tumor samples. Grade 4 toxicities included creatinine phosphokinase increase (four patients), arterial injury (one), neutropenia (one), and pneumonitis (one).
Conclusion: To the best of our knowledge, this phase II trial is the first prospective multicenter ILI trial and the first to incorporate a targeted agent in an attempt to augment antitumor responses to regional chemotherapy. Although targeting N-cadherin may improve melanoma sensitivity to chemotherapy, no difference in response to treatment was seen in this study.