NIPH Clinical Trials Search

A Study to Learn More About the Effects and Safety of Felzartamab Infusions in Adults With Primary Membranous Nephropathy (PMN)

Basic Information

Recruitment status	Recruiting
Health condition(s) or Problem(s) studied	Primary Membranous Nephropathy
Date of first enrollment	22/01/2026
Target sample size	180
Countries of recruitment	USA,Japan
Study type	Interventional
Intervention(s)	Open-Label Treatment Phase: Participants will receive several intravenous (IV) doses of felzartamab or oral tacrolimus in the Open-Label Treatment Phase. Non-Responder Treatment Phase: Participants initially randomized to felzartamab or tacrolimus who meet rescue criteria may receive regional standard of care immunosuppressive therapy (IST) per Investigator discretion or several IV doses of felzartamab, respectively, in the Non-Responder Treatment Phase.

Outcome(s)

Primary Outcome

Percentage of Participants who Achieve Complete Remission (CR) at Week 104 [Time Frame: Week 104] CR(Complete Response): proteinuria is reduced to minimal levels, renal function remains stable, and serum albumin is maintained above a defined level

Secondary Outcome

1) Percentage of Participants who Achieve Overall Remission (OR), Defined as CR or Partial Remission (PR) at Week 104 [Time Frame: Week 104] 2) Percentage of Participants who Achieve CR at Week 76 [Time Frame: Week 76] 3) Duration of CR [Time Frame: Baseline up to week 156] 4)Percentage of Participants With a Baseline Anti-Phospholipase A2 Receptor (PLA2R) Autoantibody Titer Greater Than 50 Relative Unit per Milliliter (RU/mL) who Achieve an OR at Week 76 and at Week 104 [Time Frame: Weeks 76 and 104] 5) Time to Disease Worsening [Time Frame: Baseline up to week 156] 6) Time to a Sustained Reduction in eGFR of >=30% From Baseline [Time Frame: Baseline up to week 104] 7) Absolute Change in Anti-PLA2R Autoantibody Titer in Participants Positive for Anti-PLA2R at Baseline [Time Frame: Baseline up to week 156] 8) Change From Baseline in the Patient Reported Outcome Measurement Information System (PROMIS) Fatigue Scale at Week 104 [Time Frame: Week 104] 9) Change From Baseline in PROMIS Global Assessment of Physical Health Scale at Week 104 [Time Frame: Week 104] 10) Number of Participants With Treatment Emergent Adverse Event (TEAE), Serious Adverse Event (SAE) and Adverse Events of Special Interest (AESIs) [Time Frame: From first dose of study drug up to end of follow-up (up to week 156)] 11) Felzartamab Serum Concentrations Over Time [Time Frame: Predose and at multiple timepoints post dose up to week 156] 12) Number of Participants With Anti-Drug Antibodies (ADAs) Against Felzartamab [Time Frame: Predose and at multiple timepoints post dose up to week 156]

Key inclusion & exclusion criteria

Age minimum	>= 18age old
Age maximum	<= 80age old
Gender	Both
Include criteria	1) Diagnosed with PMN in need of Immunosuppressive therapy (IST) according to the Investigator's clinical judgment. The diagnosis of PMN must be documented with the presence of nephrotic syndrome, and hypoalbuminemia, and confirmed with a kidney biopsy either during Screening or within 5 years of signing the informed consent form (ICF) [see kidney biopsy exception below for participants positive for anti-PLA2R antibodies]. For these participants, the biopsy report with redacted protected health information must be available to be reviewed by the Sponsor or an independent nephropathologist. If the participant requires a kidney biopsy during Screening, medical monitor approval must be obtained and all other eligibility criteria should be reviewed to ensure that the participant is otherwise eligible prior to performing the kidney biopsy. a. Kidney biopsy exception for anti-PLA2R antibody positive participants: Participants who are positive for anti-PLA2R antibodies and have not had a kidney biopsy performed within 5 years of signing the ICF, may be eligible for the study without undergoing a kidney biopsy based on medical monitor review confirming normal estimated glomerular filtration rate (eGFR), presence of nephrotic syndrome, hypoalbuminemia, positive anti-PLA2R antibody test (defined as an anti-PLA2R antibody titer > 20 RU/mL), and documentation provided by the Investigator that the work-up for secondary causes of membranous nephropathy (MN) was negative with no identifiable secondary causes. 2) Meets one of the following: a. Newly diagnosed PMN: defined as having never received IST for PMN in the past. b. Relapsed PMN: defined as documented achievement of CR or partial remission (PR) after treatment with an IST for PMN followed by reappearance of nephrotic range proteinuria (urine protein to creatinine ratio [UPCR] >= 3.0 gram per gram [g/g] from a 24-hour urine collection or proteinuria >= 3.5 gram per 24 hour [g/24 h]). 3) Participants must be on the maximally approved dose or maximally tolerated dose of angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) for at least 3 months prior to Screening. Participants not on the maximally approved dose of renin-angiotensin-aldosterone system (RAAS) inhibition may be enrolled provided there is documented intolerance to maximal RAAS inhibition (e.g., angioedema, development of postural hypotension, lightheadedness, hyperkalemia, etc). 4) A UPCR of >= 3.0 g/g (as determined by a 24-hour urine collection) or total proteinuria >= 3.5 g/24 h (as determined by a 24-hour urine collection) at Screening after best supportive care for at least 3 months prior to signing the ICF.
Exclude criteria	Secondary cause of MN (e.g., malignancies, medications, systemic lupus erythematosus [SLE], hepatitis B, hepatitis C, etc). Severe renal impairment defined as an eGFR =<30 mL/min/1.73m^2 at Screening or including the need for dialysis or renal replacement therapy.