OM336 in Sensitized Transplant Candidates

NCT07789431 | Not Yet Recruiting Phase 2 DMC

• 2 other identifiers: 2025-523222-40-002025
• Study Type: interventional
• Target: 12
• Locations: 2 countries
• Sites: 2

Brief Summary

This investigator-initiated, single-arm, open-label Phase IIa pilot study will evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy of OM336 in highly HLA-sensitized adults with chronic kidney disease awaiting kidney transplantation. The study will enroll 12 participants who have either a very low likelihood of receiving a compatible deceased donor kidney because of broad HLA sensitization or unacceptable donor-specific antibodies against a potential living donor. Participants will receive one 4-week course of subcutaneous OM336, with the option of a second 4-week course based on the change in virtual panel-reactive antibody (vPRA) levels after the initial treatment period. Participants will subsequently be followed for up to 24 months and, if transplantation occurs, for at least 12 months after transplantation. The primary objectives are to evaluate the safety and tolerability of OM336 through Week 24 and (co-primary endpoint) its effect on HLA sensitization, assessed by changes in vPRA levels at Week 24. Secondary and exploratory objectives include assessment of the durability of changes in vPRA and donor-specific antibodies, the number of potential compatible donors, transplantation rates, OM336 pharmacokinetics and immunogenicity, and effects on B-cell and plasma-cell immunity and antibody characteristics. An optional substudy will assess B-cell immunity in bone marrow and lymph-node samples.

Conditions

Highly Sensitized Patients Awaiting Kidney Transplant

Keywords

Kidney transplantation; HLA sensitization; T cell engager; BCMA; OM336; Desensitization

Outcome Measures

Primary Outcomes (2)

• Incidence of Treatment-Emergent Adverse Events (TEAE) [Safety and Tolerability]

  Number and percentage of participants experiencing TEAE through Week 24, including serious adverse events (SAE) and adverse events of special interest (AESI). Adverse events will be summarized by relationship to study treatment, severity, System Organ Class (SOC), and Preferred Term (PT). The number of participants experiencing each event and the number of events will be reported. Adverse events will be coded using the Medical Dictionary for Regulatory Activities (MedDRA).

  24 weeks

• Level of vPRA

  Co-primary EP: Assessment of vPRA levels at week 24.

  24 weeks

Secondary Outcomes (29)

• Incidence of Treatment-Emergent Adverse Events (TEAE) through the end of the study

  24 months

• Level of vPRA through 24 months.

  24 months

• Donor frequency according to ET Donor calculator through 24 months.

  24 months

• Number of unacceptable antigens

  24 months

• DSA MFI

  24 months

Study Arms (1)

OM336 treatment

EXPERIMENTAL

HLA-sensitized participants will receive one or (If there is a less than 5.0% reduction in vPRA after 6 months) two 4-week cycles of OM336, followed by observation through Month 24.

Biological: OM3436

Interventions

OM3436 BIOLOGICAL

OM336 will be administered in a fractionated fashion, as weekly SC injections, over the first 4 weeks of study treatment. OM336 administration will consist of two step-up doses ( 3 and 20 mg, respectively), followed by three doses at 40 mg in weekly intervals until Day 28. The (optional) second cycle will consist of 4 doses: week 26: 3 mg; week 27: 20 mg; week 28: 40 mg; week 30: 40 mg.

OM336 treatment

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Biologic male or female, 18 to 70 years of age at the time of informed consent.
• Capable of and willing to provide signed informed consent (ICF); subject must sign ICF indicating that he or she understands the purpose of procedures required for the study and is willing to participate in the study. Consent is to be obtained prior to the initiation of any study-related tests or procedures that are not part of standard-of-care for the subject's disease.
• Willing and able to comply with the visits, treatments, procedures, laboratory tests, and other requirements according to the current protocol, with a high probability for adherence and completion of the study.
• Presensitized patient
• AND:
• A dilution of the baseline serum obtained at screening by 1:100 must lead to a considerable decrease in HLA antibody MFI, with a decrease in vPRA levels by at least 1.0%.
• Living donor kidney transplant candidate Living donor transplant candidate with, according to local policy, unacceptable DSA against the scheduled donor and no option of kidney paired donation (KPD) transplantation, or within a KPD program with no transplant offer after 12 months of listing.
• AND:
• A dilution of the baseline serum obtained at screening by 1:100 must lead to a negative DSA result or to a considerable decrease in DSA MFI to permissive levels per local lab.
• Women of childbearing potential (WOCBP) must have a negative pregnancy test at screening using a highly sensitive pregnancy test. Women of childbearing potential and fertile men who are sexually active must agree to use a highly effective method of contraception (\<1% / year failure rate) during the study and for 150 days after the last dose of study drug. Women and men must agree not to donate eggs (ova, oocytes) or sperm, respectively, during the study and for 90 days after the last dose of study drug.

You may not qualify if:

• Prior treatment with any therapy that is targeted to BCMA or any other CD3-redirecting drug.
• Treatment with prohibited medications during the timeframes detailed below.
• History of severe allergic reaction (per investigator judgment) or anaphylactic reaction to monoclonal antibody-based therapies or any components of OM336.
• Congenital immunodeficiency with recurrent severe infections over the last 12 months.
• Apheresis therapy (plasmapheresis or immunoadsorption)
• CD20 mAb, e.g. rituximab or other
• CD38 mAb, e.g. daratumumab or other
• Proteasome inhibitor (bortezomib, carfilzomib)
• Tocilizumab
• Imlifidase
• Any other investigational agent
• WOCBP: Pregnant, or breastfeeding, unwilling to practice adequate contraception.
• Pulmonary compromise requiring chronic supplemental oxygen use to maintain adequate oxygenation.
• Systemic herpes simplex (HSV) or symptomatic herpes zoster virus (HZV) (infection within 3 months prior to screening, or a history of disseminated or ophthalmic or central nervous system (CNS) infection with herpes zoster.
• Active or latent tuberculosis based on a positive QuantiFERON-TB Gold Plus test or equivalent test, medical history, examination, and chest X-ray.

Sponsors & Collaborators

• Medical University of Vienna: lead

Study Sites (2)

Medical University of Vienna

Vienna, State of Vienna, 1090, Austria

Location

Charité-Universitätsmedizin Berlin

Berlin, State of Berlin, 10117, Germany

Location

Related Publications (1)

• Schatzl M, Mayer KA, Agis H, Haindl S, Kriks D, Fischer G, Exner M, Honger G, Veljancic N, Allmer DM, Graf I, Diebold M, Halloran PF, Halpin A, Li C, West L, Kozakowski N, Bohmig GA. T-Cell Engager-Mediated HLA Antibody Depletion before Kidney Transplantation. N Engl J Med. 2026 Jul 30;395(5):511-513. doi: 10.1056/NEJMc2603853. No abstract available.

  PMID: 42526030 BACKGROUND

Study Officials

• Georg A Böhmig, MD

  Division of Nephrology and Dialysis, Department of Medicine III, Medical University of Vienna

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Georg A Böhmig, MD

CONTACT

+43 1 40400 43910; georg.boehmig@meduniwien.ac.at

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: August 14, 2026
• First Posted: August 27, 2026
• Study Start (Estimated): October 1, 2026
• Primary Completion (Estimated): July 1, 2030
• Study Completion (Estimated): September 1, 2030
• Last Updated: August 28, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

AU (1); DE (1)