- Ongoing therapy with any of the following: nephrotoxic agents, competitors of renal excretion (eg, probenecid), systemic chemotherapeutic agents, systemic corticosteroids, Interleukin-2 (IL-2) and other immunomodulating agents, investigational agents (except with the expressed approval of the Sponsor); administration of any of the above medications must be discontinued at least 30 days prior to the Baseline Visit and for the duration of the study period