Research Techniques Made Simple: Preclinical Development of Combination Antitumor Targeted Therapies in Dermatology.

The identification and application of targeted therapies that inhibit critical pathways in malignant cells have shown tremendous promise for improving clinical outcomes for patients with advanced cutaneous malignancies. However, tumor cell heterogeneity, development of drug resistance, and risks of off-target effects remain barriers to prolonged remission and definitive cure. Herein, we describe the potential that combinations of antitumor targeted agents may offer in overcoming these challenges and detail techniques whereby promising combination regimens can be identified and further evaluated preclinically. Cancer cell lines and primary patient-derived malignant cells can be utilized to perform dose-response screenings in vitro for individual targeted agents before moving toward the evaluation of potential synergistic combinations. Mathematical analyses, including the Chou-Talalay method, determine combination indices and Hill slopes that permit relative comparisons among various drug combinations by quantification of synergistic activities. Further preclinical in vivo evaluation of promising single versus combination regimens may be studied in relevant mouse models of cutaneous malignancy. Ultimately, the formulation of combination targeted therapy regimens may be more broadly effective and less toxic, helping to better inform clinical trial design and prioritization.