A Clinical Trial of OM336 to Help Immunized Patients Become Eligible for Kidney Transplantation

Overview

Sponsor-declared trial summary

Key facts

Sponsor

Medical University Of Vienna

Participant type

Patients

Age range

18-64 years, 65+ years

Gender

Male and Female

Therapeutic area

Diseases [C] - Pathological Conditions, Signs and Symptoms [C23]

Decision date (initial)

2026-05-04

Transition trial

No

Low-intervention

No

Rare-disease indication

No

Vulnerable population

No

Funding sources

Ouro Medicines, Ltd. 1 Ashley Road, 3rd Floor Altrincham Cheshire, United Kingdom WA14 2DT

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Therapy, Safety, Efficacy

To evaluate the safety and tolerability of OM336, as well as its effect on HLA sensitization measured by changes in vPRA levels, in chronic kidney disease patients awaiting a renal allograft over a 6-month period.

Secondary objectives 6

1. To evaluate the effect of OM336 on the level of HLA sensitization, as reflected by changes in vPRA levels, donor frequency (for deceased donor transplant candidates), and/or DSA levels (for living donor transplant candidates) through Month 24. Serologic analyses will also include assessments of ABO blood group– and xenoantigen–reactive antibodies, as well as the characteristics of detected HLA antibodies, including binding intensity and complement-fixing capability.
2. To thoroughly evaluate the safety and tolerability of OM336 in chronic kidney disease (CKD) patients awaiting a renal allograft, from baseline through Month 24. In the event of transplantation, safety will be monitored for at least 12 months post-transplantation.
3. To assess the pharmacokinetics (PK) and immunogenicity of OM336 in CKD patients.
4. To evaluate the impact of OM336 on components of B cell immunity in peripheral blood
5. To evaluate the impact of OM336 on transplant rates.
6. Option for patients to participate in a substudy involving bone marrow aspiration and lymph node sampling (the latter obtained during the transplant procedure): To evaluate the impact of OM336 on components of B cell immunity in bone marrow and lymph nodes

Conditions and MedDRA coding

End stage renal failure

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 7

1. Biologic male or female, 18 to 70 years of age at the time of informed consent.
2. 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.
3. 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.
4. Broadly sensitized recipient on deceased donor waiting list: inclusion in the Eurotransplant Acceptable Mismatch (AM) program (>85% vPRA) for ≥24 months or inclusion in the Eurotransplant Kidney Allocaction System (ETKAS) scheme and >95% vPRA for ≥24 months, but not fulfilling the criteria in the AM program (panel reactivity includes specificities that are not acceptable by the local center; e.g. HLA antibodies with an MFI >10.000 but no prior sensitizing event documented). 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%.
5. 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.
6. 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.
7. Within 4 weeks prior to randomization, participants should be up to date on all vaccinations recommended by the local country or regional public health authority, as determined by the Investigator.

Exclusion criteria 19

1. Prior treatment with any therapy that is targeted to B Cell Maturation Antigen (BCMA) or any other CD3-redirecting drug.
2. Treatment with prohibited medications during the timeframes detailed in the study protocol.
3. History of severe allergic reaction (per investigator judgment) or anaphylactic reaction to monoclonal antibody-based therapies or any components of OM336.
4. Congenital immunodeficiency with recurrent severe infections over the last 12 months.
5. Prior desensitization treatment within 6 months prior to randomization: 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
6. WOCBP: Pregnant, or breastfeeding, unwilling to practice adequate contraception.
7. Pulmonary compromise requiring chronic supplemental oxygen use to maintain adequate oxygenation.
8. 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.
9. Active or latent tuberculosis based on a positive QuantiFERON-TB Gold Plus test or equivalent test, medical history, examination, and chest X-ray.
10. Active infection with hepatitis B (HBV), hepatitis C (HCV), or human immunodeficiency virus (HIV).
11. Clinically significant infection (e.g., requiring hospitalization or parenteral antimicrobial therapy) within 3 months prior to screening.
12. Any infection requiring oral antimicrobial therapy within 2 weeks prior to inclusion.
13. A history of malignancy within the past 5 years (except for successfully treated basal or squamous cell carcinoma of the skin, or successfully treated carcinoma in situ of the cervix, with no evidence of recurrence). Note: low-grade prostate cancer (Gleason score of 6 or less, confined to the prostate and under surveillance/monitoring without need for imminent surgical intervention) is permitted, per judgment of the investigator.
14. Live vaccine within 3 months prior to screening.
15. Uncontrolled psychiatric conditions (eg, alcohol or drug abuse), dementia, or altered mental status precluding study enrollment according to the judgment of the investigators
16. Inadequate liver function at Screening: Total bilirubin >2 × the upper limit of normal (ULN) except if due to Gilbert syndrome; Alanine transaminase (ALT) and/or aspartate aminotransferase (AST) >3 × ULN
17. Currently enrolled in or participated in another clinical research study with investigational drug or device within 30 days or 5 drug half-lives of the investigational product (whichever is longer), prior to screening.
18. Any clinically significant underlying illness that, in the opinion of the Investigator, may compromise study participation, present a safety risk to the participant, or may confound the interpretation of the study results, including general non-adherence to medication
19. Known allergy to dexametasone and its excipients, diphenhydramine and its excipients, acetaminophen and its excipients or to valacyclovir and its excipients.

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 2

1. Assessment of the safety and tolerability of OM336 through week 24.
2. Co-Primary endpoint: Assessment of vPRA levels at week 24.

Secondary endpoints 22

1. Safety and tolerability through month 24, and in the event of transplantation, safety over at least 12 months post-transplantation.
2. vPRA at 3, 12, 15, 18, 21, and 24 months.
3. Donor frequency according to ET Donor calculator at 3, 6, 12, 15, 18, 21, and 24 months.
4. Number of unacceptable antigens that can be delisted at 3, 6, 12, 15, 18, 21, and 24 months, according to the following rules: (i) Unacceptable “plausible” antigens: if <1000 MFI; (ii) locally unacceptable antigens without recorded sensitizing event: if <10.000, provided a peri-transplant desensitization program is available (Vienna 6) or if <3000, if no such program is available (Berlin). According to the ET rules, eligibility for AM allocation will be re-evaluated by the ET central lab.
5. For recipients of a living donor kidney transplant, the MFI of the immunodominant DSA at 3, 6, 12, 15, 18, 21, and 24 months.
6. OM336 study drug PK, as well as assessment of anti-drug antibodies (ADA) (schedule: see also section 8.3.). PK Parameters: maximum concentration, time to maximum concentration, area under the plasma concentration-time curve. Additional parameters (half-life, clearance, volume of distribution) will be calculated, as appropriate.
7. vPRA defined according to a SAFB threshold of >MFI 1000 at 3, 6, 12, 15, 18, 21, and 24 months.
8. vPRA defined according to a SAFB threshold of >MFI 3000 at 3, 6, 12, 15, 18, 21, and 24 months.
9. vPRA defined according to a SAFB threshold of >MFI 10000 at 3, 6, 12, 15, 18, 21, and 24 months.
10. HLA antibody characteristics (MFI course, complement fixing capability) at 3, 6, 12, 15, 18, 21, and 24 months.
11. Crossmatch course for transplant offers, with retrospective serum evaluation from the beginning of the trial in 3-monthly intervals before transplantation
12. Levels of IgG, IgM, IgA at 3, 6, 12, 15, 18, 21, and 24 months.
13. Levels of free light chains at 3, 6, 12, 15, 18, 21, and 24 months.
14. Blood group and xeno-reactive antibodies at 3, 6, 12, 15, 18, 21, and 24 months.
15. Vaccination titers including hepatitis B.
16. Torque Teno virus (TTV) load at 3, 6, 12, 15, 18, 21, and 24 months.
17. Counts of peripheral blood B cell (sub)populations including number and composition of peripheral B cells measured by high sensitivity-flow (CD20+/low/CD27+ and CD27-) at 3, 6, 9, 12, 15, 18, 21, and 24 months.
18. Counts of peripheral blood T cells and T cell (sub)populations at 3, 6, 9, 12, 15, 18, 21, and 24 months.
19. Peripheral blood transcriptome analysis at 3, 6, 9, 12, 15, 18, and 24 months.
20. Serum soluble BCMA (sBCMA), blood cytokines, chemokines, and markers of inflammation at 3, 6, 9, 12, 15, 18, and 24 months
21. Transplantation rate through Month 24.
22. Optional exploratory endpoints for patients participating in a substudy of bone marrow analysis and lymph node analysis may include: Number and composition of bone marrow B and plasma cells by high sensitivity-flow cytometry; of lymph node (inguinal taken during Tx) B and PC at the time of transplantation by immunohistochemistry; Peripheral B cell receptor repertoire compared to bone marrow B/ plasma cell receptor repertoire.

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 1

Auxiliary 4

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Medical University Of Vienna

Sponsor organisation

Medical University Of Vienna

Address

Spitalgasse 23, Alsergrund Alsergrund

City

Vienna

Postcode

1090

Country

Austria

Scientific contact point

Organisation

Medical University Of Vienna

Contact name

Division of Nephrology and Dialysis, Department of Medicine III

Public contact point

Organisation

Medical University Of Vienna

Contact name

Division of Nephrology and Dialysis, Department of Medicine III

Locations

1 EU/EEA country · 1 investigational sites

By country

Investigational sites

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 9 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

Application history

1 submissions — initial application plus substantial / non-substantial modifications