Efficacy of Acthar gel and Tacrolimus in DNA-JB9 Positive Fibrillary Glomerulopathy

Introduction

Fibrillary glomerulopathy (FGN) is a rare glomerular disease characterized by the deposition of randomly arranged fibrils that results in proteinuria and end-stage renal disease (ESRD) in up to 50% of patients within 2 years. The FACT trial is a prospective, randomized, open-labeled study of patients with biopsy-proven, DNA-JB9 positive FGN comparing the safety and efficacy of repository corticotropin (ACTH) injection, Acthar gel alone or in combination with tacrolimus on proteinuria and change in estimated glomerular filtration rate (eGFR).

Methods

Patients (N = 34) were randomized to ACTH 80 units subcutaneous 2×/wk alone or in combination with tacrolimus (1.0 mg 2×/d) for 12 months. Changes in the mean urinary protein-to-creatinine ratio (UPCR) and eGFR were reported at 6 and 12 months and last follow-up.

Results

A total of 34 patients completing 1 year of therapy were analyzed. In the ACTH-alone group (19 patients), UPCR decreased from a mean of 6.21 ± 0.8 g/g at baseline to 2.92 ± 0.90 g/g (P < 0.009) at 6 months and 1.76 ± 1.3 g/g (P < 0.02) at month 12. In the combination group (15 patients), mean UPCR decreased significantly from 6.00 ± 1.4 g/g at baseline to 4.27 ± 1.1 g/g (P < 0.01) and to 1.83 ± 0.90 g/g (P < 0.0006) at 6 and 12 months, respectively. At 12 months, combination therapy induced complete or partial responses in 13.3% and 53.3% compared with 15.8% and 26.3% in the ACTH alone group, respectively.

Conclusion

Repository ACTH (Acthar gel) significantly reduced UPCR at 6 and 12 months. The addition of tacrolimus was not additive with ACTH in reducing proteinuria or stabilization of eGFR. Acthar gel is an effective antiproteinuric therapy for DNA-JB9 positive FGN.