Medarex, Inc (PRINCETON, New Jersey), a biopharmaceutical company focused on the discovery, development, and commercialization of fully human antibody-based therapeutics, announced the allowance of an investigational new drug application (IND) filed with the US FDA for MDX-1342 for rheumatoid arthritis (RA). MDX-1342 is a fully human antibody that targets CD19, a molecule specifically expressed on normal B-cells and malignant B-cells in diseases such as chronic lymphocytic and acute lymphoblastic leukemias as well as follicular nonHodgkin's, diffuse large B-cell, and mantle cell lymphomas.

The FDA-cleared IND for the treatment of RA is expected to enroll up to 90 patients with RA. The randomized, single-dose, dose-escalation, placebo-controlled phase I clinical trial is designed to evaluate the safety and tolerability profile of MDX-1342 and to determine the dose range for B-cell depletion.

CD19 is a B-cell specific membrane protein that is broadly expressed during B-cell development, from the pro-B-cell to the early plasma cell stage. Clinical studies have demonstrated that depleting monoclonal antibodies directed against CD20, another B-cell specific membrane protein that has a more restricted expression pattern than CD19 during B-cell development, are effective in treating RA and various B-cell malignancies, and show promise in treating other inflammatory diseases such as systemic lupus erythematosus and multiple sclerosis.