Rituximab in treatment of collapsing FSGS-A case series

Collapsing focal segmental glomerulosclerosis (cFSGS) is an aggressive glomerular disease presenting as a nephrotic syndrome that has lower rates of remission with conventional immunosuppressive therapy and rapidly progresses to end-stage-renal-disease (ESRD). We report eight cases of HIV-negative cFSGS treated with rituximab.

The current report is a retrospective case series of cFSGS treated with rituximab from January 2011 to March 2020, at varying phases of the disease.

Eight out of the 70 cFSGS patients received rituximab. The median age of patients was 30 years (IQR 24.25-37.5); five patients were males. The median serum creatinine, mean serum albumin and median 24 hours urinary protein at presentation was 0.9 (IQR 0.66-1.27) mg/dL, 2.95 ± 1.15 g/dL, 4.87 (IQR 1.64-5.75) g/day, respectively. Two patients were steroid-resistant, one steroid and tacrolimus dependent, one steroid and cyclosporine dependent, two steroids and tacrolimus resistant, one steroid, tacrolimus, cyclophosphamide, mycophenolate mofetil resistant and one steroid-resistant and tacrolimus dependent before rituximab therapy. Rituximab was given either as targeted therapy (after an initial dose of 375 mg/m² ; patients having CD-19 levels >5/μL or >1% at 1 month received additional low-dose [100 mg] of rituximab), or weekly regimen. Five patients received CD-19 targeted rituximab; three received weekly doses of 375 mg/m² , cumulative doses being 820 ± 228.03 mg, and 1800 ± 721.11 mg, respectively. At the end of median follow-up of 15 months, five (62.5%) patients were in remission (three partial, two complete remissions), two (25%) were resistant to therapy; one (12.5%) progressed to ESRD.

Rituximab is reasonably safe and achieves/maintains remission in 60% of cFSGS cases.