NEW YORK (AP) — Genentech Inc. and Biogen Idec Inc. said Wednesday their drug Rituxan failed to significantly reduce kidney inflammation caused by lupus, the main goal of their late-stage trial. Rituxan is approved for use in rheumatoid arthritis and non-Hodgkin lymphoma, and the companies hoped to get it approved as a treatment for lupus nephritis. The companies said they will continue to look for new ways to treat lupus, but did not say if they will continue testing Rituxan for that illness. Lupus, an autoimmune disorder, is often accompanied by inflammation of the kidneys. In the trial, 144 patients were given either Rituxan or a placebo. All patients received standard treatment with an immunosuppressant, mycophenolate mofetil, and corticosteroids. Treatments were given at the beginning of the trial and repeated six months later, and their health was monitored at 24 weeks and 52 weeks. Rituxan did not prove significantly more effective at improving kidney function or reducing urinary sediment or high levels of protein in urine, which can indicate kidney damage. The companies said side effects were similar in the Rituxan patients and the placebo patients. Side effects that were more common in Rituxan patients included low white blood cell counts and low blood pressure.