Abstract: FR-PO1057

Rituximab (RTX) Treatment of Fibrillary Glomerulonephritis (FGN): A Pilot Study

Session Information

Category: Glomerular

  • 1005 Clinical Glomerular Disorders

Authors

  • Erickson, Stephen B., Mayo Clinic, Rochester, Minnesota, United States
  • Alexander, Mariam P., Mayo Clinic, Rochester, Minnesota, United States
  • Nasr, Samih H., Mayo Clinic, Rochester, Minnesota, United States
  • Fervenza, Fernando C., Mayo Clinic, Rochester, Minnesota, United States
Background

FGN is a rare glomerular disease for which no standard treatment is available. Renal survival is poor with nearly 50% of patients progressing to ESRD within 4 yrs.

Methods

We recruited 11 patients with biopsy proven idiopathic FGNs into an open-label study testing the efficacy of RTX in reduction of proteinuria and preservation of kidney function. Patients’ age ranged from 35 to 77 yrs, mean 58.5. Eight were females. All patients received 2 doses of RTX 1 gm each, at day 1 and day 14 with identical retreatment at 6 mos. Prespecified end points included 24 hr creatinine clearance (CrCl) and proteinuria at 12 mos.
A logarithmic transformation was applied to CrCl values at each time point prior to comparing the values using a paired t-test.
No serious adverse events.

Results

All patients completed 12 mos of the study. There was no significant change in CrCl: 47.73 (SD 24.02) at baseline, 43.73 (SD 23.08) ml/min/SA at 12 mos, p=0.21[Fig 1]. Proteinuria decreased from 3824.7 (SD 1468.8) to 2650.5 (SD 1692.2) mg/24h, or nephrotic to non-nephrotic p=0.068. A subgroup of 3 (27%) patients had a dramatic response[Fig 2]. CD-19 B cells, the RTX target, dropped from an avg of 158.9 cells/mcL pre-RTX to nearly 0 at day 28 post-RTX. With the exception of patients 1 and 6 who had rebound by day 180 after both RTX treatments, all patients remained CD-19 cell depleted throughout the study.

Conclusion

Following 4 doses of RTX, patients had stable renal function. There was a tendency for proteinuria to decrease although it did not quite meet statistical significance(p= 0.068). A subgroup of patients showed remarkable reduction in proteinuria. For a previously untreatable disease, this is good news.

Figure 1

Figure 2

Funding

  • Commercial Support