The purpose of this study is to see if filgotinib and/or GS-9876 can be safe and helpful to treat patients with Lupus Membranous Nephropathy. These are both oral medications. The study will last for about one year and will involve 18 study visits. Patients will be assigned to get either filgotinib or GS-9876 at the beginning of the study. At Week 16, they will be evaluated to see if their LMN is improving. If so, they will remain on whichever drug they received. If not, they will switch to the other drug. At Week 32, patients will once again be evaluated. Based on those results, patients may remain on the same drug, or switch to the other group. This process will be blinded so that even though you will always be getting active drug, you will not know which one.