List of products in the National Drug Code with proprietary name . Belatacept is used to help prevent organ rejection in people who have received a kidney transplant. It is used along with other medications (such as mycophenolate, corticosteroids) to allow your new organ to function normally. Belatacept belongs to a class of drugs known as immunosuppressants. It works by weakening your body's natural defense (immune system) to prevent your body from rejecting the new kidney.