Targeted Therapy in Metastatic Melanoma

Following an established track record set by other malignancies:
- Such as breast cancer (trastuzumab / pertuzumab) and leukemia / GIST (imatinib):
  - Melanoma has undergone a paradigm change in cancer treatment
Of note, to date, all targeted therapy agents used to treat melanoma have the advantage of oral administration:
- Given the ease of administration and the often-profound disease control seen with these agents, it is our practice to routinely molecularly characterize tumors of patients with metastatic disease:
  - So that targeted therapy treatment options can be integrated into an overall treatment strategy
While the MAPK pathway is the most commonly targeted pathway in melanoma:
- Using BRAF / MEK inhibition:
  - A number of other mutations have been targeted and described
  - These less common mutations are of significant interest in a disease with an overall high prevalence
In the case of KIT mutations, several case reports have demonstrated a benefit for individual patients with KIT mutations treated with a KIT inhibitor:
- In a phase II study, 28 patients with unresectable metastatic KIT-mutated melanoma were treated with imatinib mesylate:
  - In this study, 16% of patients had durable responses that lasted more than a year
- Continued work is needed to identify and develop mechanisms to block additional known pathogenic mutations in melanoma

Published by Rodrigo Arrangoiz MS, MD, FACS, FSSO