IntroductionThere is a scarcity of research comparing the efficacy of cyclophosphamide and mycophenolate mofetil in childhood nephrotic syndrome. The aim was to evaluate the efficacy and safety of oral cyclophosphamide (CYC) and mycophenolate mofetil (MMF) in children with steroid-sensitive nephrotic syndrome in terms of the proportion of children who have been off steroids for at least 6 months without proteinuria (responders).MethodsThis open-label retrospective-prospective comparative study was conducted in a pediatric nephrology clinic of a referral center for children between 1 and 18 years of age with FR/SD nephrotic syndrome. Group A consisted of patients who received oral cyclophosphamide (100, 25% female) at a dose of 2–2.5 mg/kg once daily for a period of 8–12 weeks. Group B consisted of patients who received oral mycophenolate mofetil (n = 61, 18% female) (dose: 800–1200 mg/m2) for at least 12 months. Responders were defined as children who were off steroids for at least 6 months along with absence of proteinuria.ResultsIn the CYC group, 50% of the patients were responders, whereas 54% of the patients in the MMF group were responders (p = 0.614). The time to first relapse with CYC was 7 months (IQR 5.25–11) compared to 7 months (IQR 3.5–12) with MMF (p = 0.092). The relapse rate in the CYC group was 1.77 relapses per patient-year compared to 1.295 relapses per patient-year in the MMF group. The difference in relapse rate was significant (-0.474; 95% CI, 0.09 to 0.86 relapses/person-year) (p value = 0.009). Multivariate analysis revealed that an age of less than 5 years at the start of treatment was a significant factor for a better response to MMF (p value = 0.039, OR = 2.988, CI -1.055-8.468).ConclusionsThe efficacy of MMF was similar to that of CYC in terms of response (6 months without steroids) in children with FR/SD nephrotic syndrome. MMF showed a favorable response in terms of the frequency of relapse and treatment failure.Registration of the study with Clinical Trials Registry of India(http://ctri.nic.in;CTRI/2021/06/034421) (Dt: 28/06/2021).