ZURICH: Roche has won the U.S. Food and Drug Administration's breakthrough therapy tag for its drug Gazyva in lupus nephritis, the Swiss drugmaker said on Wednesday, boosting its efforts to recycle the 2013-approved lymphoma medicine for new indications.There are no FDA-approved medicines for lupus nephritis, a life-threatening symptom of the autoimmune disease lupus in which the kidneys grow inflamed. Roche has heralded Gazyva's potential in the new disease area in helping turn the drug that had sales of 390 million Swiss francs ($392.59 million) last year into a commercial success. ($1 = 0.9934 Swiss francs)