An Open-Label, Long-term Study of GFB-887 in Patients With Glomerular Kidney Diseases

Inclusion Criteria: * Participants with FSGS/TR-MCD who have completed the treatment phase from an interventional clinical study with GFB-887. Participants who were discontinued for rising proteinuria from a GFB-887 interventional study may be considered for enrollment following consultation with the Medical Monitor. * Participants who enrolled in any other interventional study during the time between completion of the prior GFB-887 interventional study and this study may be considered for enrollment following consultation with the Medical Monitor. Exclusion Criteria: * Participant is unable to take oral medications * Participant has an unstable medical condition based on medical history, physical examination, laboratory tests, ECGs, vital signs or is otherwise unstable in the judgement of the Investigator which would pose a risk to the participant or interfere with study evaluation, procedures, or completion * Evidence of significant hypersensitivity, intolerance, or allergy to any component of investigational product GFB-887