Omics of Rituximab-resistance (CONFUCIUS)

Identification of a Pharmacogenomic Signature for Anti-B Cell Precision Therapy in Membranous Nephropathy

The CONFUCIUS project aims to establish a personalised medicine framework for MN patients by integrating pharmacogenomics with other -omics technologies in order to identify biomarkers that predict response to RTX, ultimately enabling optimized treatment selection. Using a multiomics approach, we will analyse genetic variants, serum and kidney proteomics, and serum metabolomics profiles from a well-characterised retrospective cohort of MN patients to uncover predictive biomarkers of RTX response.

This is a non-pharmacological interventional study, conducted on biological samples from patients stored in the local biobank and on samples from healthy volunteers, which will be collected and subsequently stored in the biobank.

Study Overview

• Status: Not yet recruiting
• Conditions: Membranous Nephropathy
• Intervention / Treatment: Genetic: Multi-omics Analysis; Procedure: Sample collection

Detailed Description

Primary Membranous Nephropathy (MN) remains a leading cause of nephrotic syndrome (NS) in adults. MN is an autoimmune disorder where autoantibodies (abs) target antigens at the podocyte-glomerular basement membrane interface altering the renal filtration barrier, frequently leading to full-blown nephrotic syndrome (NS) and chronic kidney failure. NS, marked by massive proteinuria, hypoalbuminemia and generalized oedema, severely affects quality of life and can cause life-threatening complications. The discovery of pathogenic antibodies (Abs) against podocyte autoantigens - including the phospholipase A2 receptor (PLA2R) in 70% of primary MN, and more recently thrombospondin type-1 domain containing 7A (THSD7A)- has supported the use of targeted anti B-cell therapies. The anti-CD20 monoclonal Ab Rituximab (RTX) is increasingly used as first-line therapy for MN4, thanks to its better safety profile compared to glucocorticoids, alkylating agents or calcineurin inhibitors, which cause broad immunosuppression. RTX induces a profound circulating B-cell depletion, which persists for several months and is frequently followed by reduced Ab titre and NS remission. However, RTX is ineffective in up to 40% of cases, and about one third of initial responders relapse8, potentially leading to RTX-dependency and prolonged nephrotic range proteinuria with associated complications. Although RTX typically achieves complete peripheral blood B-cell depletion, the reasons for variable patient responses remain unclear. Proposed resistance mechanisms include anti-CD20 Ab-antigen complex internalization, anti-RTX Ab production, incomplete elimination of autoreactive B cell clone in lymphoid organs and failure to target CD20-negative plasma cells8. None of these mechanisms can be envisaged a priori to distinguish between RTX-sensitive and RTX-resistant patients. Therefore, almost half of MN patients are exposed to potential B cell depletion-related complications with negligible or no clinical benefit and high-risk of progression to end-stage kidney disease (ESKD). RTX-resistant patients might benefit from next-generation anti-CD20 monoclonal Abs such as obinutuzumab, which induces a longer and deeper B-cell depletion than RTX and depletes B cells in lymphoid tissues. In preliminary studies it was effective in several RTX-resistant MN patients9. The CONFUCIUS project aims to move beyond current trial-and-error strategies to a precision medicine framework, by integrating pharmacogenomics with other -omics markers that can predict the response to anti-CD20 treatments, ensuring that the right therapy is administered to the right patient at the right time. Consequently, RTX or obinutuzumab will be safely administered to patients exhibiting an adequate response profile, while avoiding unnecessary treatment in potentially anti-CD20 Ab-resistant patients. Subjects with this anti-CD20 antibody- resistant profile, may benefit from alternative strategies which could be identified through pharmacogenomic analyses. Potential strategies for anti-CD20-resistant patients may include targeting CD20-negative B cells, co-stimulatory pathways, or components of the complement system, offering new avenues for patients unresponsive to CD20+B cell-depleting agents. The favourable cost-effectiveness profile for these specific patient subgroups could offset the additional cost of these alternatives.

PERSONALIZED MEDICINE DIMENSION Due to significant variability in pathophysiology and clinical presentation, the treatment of MN remains challenging. MN patients usually receive optimal supportive care for 3-to-6 months, during which approximately one-third of them experience spontaneous remission. For those with persistent proteinuria and at risk of progressive kidney injury, immunosuppressive therapy, including RTX is recommended. However, up to 30-40% of patients are refractory to treatment, putting them at high risk of persistent NS and progression to end stage kidney disease (ESKD). For these patients, alternative therapeutic strategies are often introduced too late, after prolonged ineffective treatment and significant, treatment- and disease-related irreversible complications. By leveraging state-of-the-art methodologies on existing biobanked biological samples from well- characterized MN patients, this project aims to identify gene variants, proteomic and metabolomic biomarkers, and specific B or other immune cell signatures associated with RTX resistance. For patients resistant to both RTX and obinutuzumab, comprehensive re-analysis will be conducted to identify markers of anti-CD20 resistance and discover potential molecular targets to guide the development of alternative therapeutic strategies. This approach will facilitate the development of a standardized, robust, and specific algorithm for therapeutic decision-making. Results from this project will move beyond current trial-and-error strategies to a precision medicine framework, ensuring the right therapy is delivered to the right patient at the right time.

KNOWLEDGE GAP AND UNMET MEDICAL AND PATIENT NEED RTX is ineffective in a substantial subset of MN patients likely due to insufficient or transient depletion of anti-PLA2R abs. As RTX treatment fails in up to 40% of patients, the nephrologists face the dilemma of either exposing patients to the potential risks of B-cell depletion or providing conservative treatment with a high-risk of progression to ESKD. This issue is not trivial, because NS is associated with potentially life-threatening complications and substantially reduces the quality of life of the patient. The identification of markers predicting the response to RTX or to the novel anti-CD20 antibody obinutuzumab may guide choice of the best anti-CD20 approach, and will distinguish patients who are not likely to respond to CD20+B cell depletion. This will avoid unnecessary exposure to the risk of B cell-related immunosuppression and possibly offer anti- CD20 Ab- resistant patients alternative options with the potential of limiting disease progression.

The general aim of this project is to identify specific pharmacogenomics/multi-omics markers of response/resistance to RTX in MN by integrating pharmacogenomics with other -omics technologies, and to evaluate whether emerging anti-CD20 Abs represent a valuable option for patients with RTX resistance signature.

For patients resistant to obinutuzumab, the study will investigate alternative mechanisms of anti-CD20 Ab resistance and search potential therapeutic targets. The results will be instrumental in tailoring individualized anti-B cell or alternative therapeutic strategies, advancing personalized medicine and minimizing drug-related side effects, by preventing the use of ineffective treatments and optimizing healthcare resources.

• Study Type: Observational
• Enrollment (Estimated): 120

Contacts and Locations

• Study Contact: Name: Matias Trillini, M.D.; Phone Number: +390354535411; Email: matias.trillini@marionegri.it
• Study Contact Backup: Name: Marina Noris, Ph.D.; Phone Number: +390354535362; Email: marina.noris@marionegri.it

Study Locations

• Italy
  • BG
    • Ranica, BG, Italy, 24020
      • Clinical Research Centre for Rare Diseases Aldo e Cele Daccò
      • Contact: Matias Trillini, MD; Phone Number: +390354535411; Email: matias.trillini@marionegri.it
      • Principal Investigator: Matias Trillini, M.D.
      • Principal Investigator: Marina Noris, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

Patient biological samples. The study will use samples collected from patients of the PROMENADE Study (NCT06242327) with a histologically confirmed diagnosis of MN, and who were treated with RTX. The samples, collected before and after RTX treatment, include DNA (n=300), sera (n=120), and peripheral blood mononuclear cells (PBMCs) (n=65), and are stored at the biobank of one of the IRFMN's site, the Clinical Research Center for Rare Diseases Aldo e Cele Daccò.

Healthy volunteers: for comparison reasons, 60 volunteers, matched for age and sex, will also be analyzed.

Description

Patients

Inclusion Criteria:

• Adult patients
• Biopsy-proven primary membranous nephropathy (MN)
• Written informed consent for storage of biological samples in the local biobank

Exclusion Criteria:

• Absence of signed written informed consent for the storage of samples in the biobank

Healthy subjects

Inclusion Criteria:

• Adult male and female
• Written informed consent

Exclusion Criteria:

• History of renal diseases, autoimmune disorders, diabetes mellitus, current allergies
• Subjects who have taken antibiotics, anti-inflammatory drugs, or antihistamines within the past 7 days

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Sera samples of RTX-resistant patients; 30 RTX-resistant patients (randomly selected among those with serum samples available)	Genetic: Multi-omics Analysis; High-level molecular profiling (pharmacogenetics, proteomics, metabolomics, and scRNAseq) on patient samples
Healthy volunteers; Healthy, age- and sex-matched subjects will be analysed as controls.	Genetic: Multi-omics Analysis; High-level molecular profiling (pharmacogenetics, proteomics, metabolomics, and scRNAseq) on patient samples; Procedure: Sample collection; One single blood sample of approximately 25 ml.
Sera samples of RTX-responsive MN patients; 30 RTX-responsive MN patients (matched for age, sex, baseline eGFR and proteinuria, and comorbidities with RTX-resistant MN)	Genetic: Multi-omics Analysis; High-level molecular profiling (pharmacogenetics, proteomics, metabolomics, and scRNAseq) on patient samples

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Multiomics analyses	Pharmacogenomic/multi-omics biomarkers predicting RTX response/resistance in MN (e.g., genetic variants in FCGR/FCGRT/C1QA/CD20/BAFF/IL-6, serum proteomics/metabolomics profiles, RTX-resistant immune cell signatures via scRNAseq/CITE-seq).	At baseline and at 12 months after RTX treatment

Collaborators and Investigators

• Sponsor: Mario Negri Institute for Pharmacological Research
• Investigators: Study Director: Giuseppe Remuzzi, M.D., Istituto Di Ricerche Farmacologiche Mario Negri

Study record dates

Study Major Dates

• Study Start (Estimated): April 1, 2026
• Primary Completion (Estimated): March 1, 2029
• Study Completion (Estimated): March 1, 2029

Study Registration Dates

• First Submitted: February 10, 2026
• First Submitted That Met QC Criteria: February 10, 2026
• First Posted (Actual): February 18, 2026

Study Record Updates

• Last Update Posted (Actual): February 18, 2026
• Last Update Submitted That Met QC Criteria: February 10, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: pharmacogenetics; rituximab; metabolomics; proteomics; scRNAseq; B cells; membranous nephropathy
• Additional Relevant MeSH Terms: Urogenital Diseases; Male Urogenital Diseases; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Autoimmune Diseases; Immune System Diseases; Glomerulonephritis; Nephritis; Glomerulonephritis, Membranous; Investigative Techniques; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Specimen Handling
• Other Study ID Numbers: CONFUCIUS

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No