PRINCETON, N.J. (AP) — Medarex Inc. said Wednesday it received Food and Drug Administration approval to start clinical testing on humans of a cancer drug candidate called MDX-1203. Medarex is planning an early stage trial of the drug, a small study focused on side effects and dosing. MDX-1203 contains an antibody that targets a protein called CD70, which is found in leukemia, lymphoma, renal cell carcinoma and other cancers. The early stage trial will include patients with advanced or returning renal cell carcinoma and non-Hodgkin’s lymphoma. Medarex is also developing a drug candidate called ipilimumab to treat advanced metastatic melanoma, a deadly skin cancer, among other forms of the disease. The company is testing five other potential cancer treatments, along with drugs intended to treat lupus, rheumatoid arthritis, and anthrax.