What is your preferred add-on for membranous lupus nephritis (2.2 grams of protein, normal creatinine) in a young woman who is currently on hydroxychloroquine and mycophenolate 1500 mg 2x daily?

Persistent proteinuria in patients with any ISN/RPS class of LN is problematic recognizing goal is to achieve EULAR targets of uPCR < 25% at 3 months, < 50% at 6 months, and < 0.5 - 0.7 at 12 months compared to baseline. Proteinuria is renal tubulointerstitium toxic inducing pro-inflammatory and fibrotic factors that result in kidney damage and declining eGFR. The first issue is determining if the presence of proteinuria is best explained by ongoing disease activity vs the consequence of prior but now remitted immune-mediated injury (eg perfusion of nephrons with chronically injured slit diaphragm now permissive for albumin and proteins). If the proteinuria is related to the latter would intensify, as tolerated, one or more of the pillars o...

First, I’ll assume that due diligence was done with the following:

• renal protective therapies like ARB/ACEi, SGLT2I have been used as part of therapy,
• HTN has been well controlled,
• HCQ drug levels have been monitored to ensure adherence and keeping the level at 1000-1200 ng/mL (my goal for lupus nephritis),
• mycophenolate acid levels have been monitored to ensure adherence,
• vitamin D levels monitored and supplemented to keep levels around 40 ng/mL (shown to increase remission rates in lupus nephritis by a previous Johns Hopkins study),
• and that the proteinuria is truly due to active lupus nephritis. For example, if this is two years into treatment, I’d want a biopsy, if 4 months in, no biopsy is needed.

If all the above is satisfied, then...