Rituximab is the standard treatment for childhood-onset complex relapsing or steroid-dependent nephrotic syndrome (FRNS/SDNS). The majority of patients, however, regain FRNS/SDNS after peripheral B cell recovery. For a study, researchers undertook a multicenter, randomized, double-blind, placebo-controlled experiment to see if giving mycophenolate mofetil (MMF) following rituximab may help avoid treatment failure (FRNS, SDNS, steroid resistance, or use of immunosuppressive agents or rituximab). In all, 39 patients (39 per group) were given rituximab, then either MMF or placebo until day 505 (treatment period). Throughout the treatment and follow-up periods, the primary outcome was time to treatment failure (TTF) (until day 505 for the last enrolled patient). 

TTFs were clinically but not statistically longer in patients given MMF following rituximab than in those given rituximab alone (median, 784.0 versus 472.5 days, hazard ratio [HR], 0.59; 95% CI, 0.34 to 1.05, log-rank test: P=0.07). Researchers did a post-hoc analysis confined to the treatment period since the majority of patients in the MMF group presented with treatment failure after MMF termination and discovered that MMF after rituximab extended the TTF and reduced the chance of treatment failure by 80%. (HR, 0.20; 95% CI, 0.08 to 0.50). Furthermore, MMF following rituximab lowered the relapse rate and daily steroid dosage by 74% and 57%, respectively, during the therapy period. In both groups, the frequency and severity of adverse events were comparable. MMF administration following rituximab may be effective in avoiding treatment failure and is generally tolerated, albeit the relapse-prevention benefit fades after MMF withdrawal.

Reference:jasn.asnjournals.org/content/33/2/401