Rituximab (Rituxan) is not approved by the Food and Drug Administration (FDA) for the treatment of IgA nephropathy. There have been many treatments proposed for IgA nephropathy, but no specific treatment has shown remarkable success. Hence, it is best that your son consult with his nephrologist about management. There is no difference in the management of IgA nephropathy between Stage 3 or Stage 4 chronic kidney disease (CKD). His current management appears to be successful. I suggest that he continue to consult with his nephrologist.