Safety, Tolerability and Efficacy of AntiBKV As Treatment of BKV Infection in Kidney Transplant Recipients

Inclusion Criteria:

1. Male or female aged 18 years or older

2. Kidney transplantation within 24 months prior to enrollment

3. Kidney transplant recipient with first-time BKV DNAemia (evaluated during routineclinical monitoring by the local laboratory and acknowledged by a physician withinfour months prior to Day 1). BKV DNAemia is either defined by BKV-DNAemia of onetime >10,000 copies/mL, or >1,000 copies/mL sustained for at least one week (confirmed by two consecutive measurements. Note: The second, most recent laboratoryvalue must be acknowledged by a physician within four months prior to Day 1)

4. Kidney transplant recipients with adequate and/or stable allograft function asindicated by estimated glomerular filtration rate ((e)GFR) ≥ 30 mL/min

5. Female subjects (if of childbearing potential) must agree to use adequate andreliable contraceptive measures throughout their participation in the trial.Contraceptive use by women should be consistent with local regulations regarding themethods of contraception for those participating in clinical studies

6. Ability to provide written informed consent

Exclusion Criteria:

1. Patients with previous diagnosis of BKV DNAemia (defined as one time > 10,000copies/mL, or > 1,000 copies/mL sustained for at least one week (confirmed by twoconsecutive measurements) since last kidney transplantation

2. Known hypersensitivity to any component of the IMP

3. Transplanted kidney disease with an estimated glomerular filtration rate ((e)GFR) < 30 mL/minute at screening

4. Uncontrolled acute or chronic infection other than BKV infection at screening whichmight interfere with study participation at the discretion of the investigator

5. Recipients who are treated or planned to be treated with a mTOR inhibitor orbelatacept as part of their immunosuppression regimen post-transplantation at thetime of enrollment and during the study period

6. Recipients who are treated or planned to be treated during study participation withleflunomide at the time of enrollment and during the study period

7. Recipients who in the opinion of the investigator are likely to requireantibody-depletion therapy during trial participation. Antibody-depletion therapiesinclude but are not necessarily limited to plasmapheresis, immunoadsorption, andintravenous immunoglobulins (IVIg)

8. Recipients with active kidney transplant rejection or FSGS

9. Recipients who have medical conditions or receive concomitant medications thatprevent the recipient from undergoing allograft biopsy

10. Recipients with known DSA (de novo or pre-transplantation). Kidney transplantrecipients with low-level pretransplant DSAs (< 1000 mean fluorescence intensity (MFI)) can be included if no impact on the study assessments is expected by thediscretion of the investigator.

11. (exclusion criterium deleted)

12. Recipients with extremely high BKV DNAemia (> 10,000,000 copies/ml) or hemorrhagiccystitis

13. Recipients who in the opinion of the investigator are likely to develop recurrentnative kidney disease (e.g. IgA nephritis, FSGS, C3 glomerulonephritis)

14. Recipients with a functionally significant ureteral stricture

15. Pregnant or nursing (lactating) women

16. Known current active or latent TB or any history, in the opinion of theinvestigator, that confers a risk of reactivation of latent TB and precludes the useof conventional immunosuppression

17. History of splenectomy or asplenia

18. Any condition, that in the opinion of the investigator, would interfere with theevaluation of the investigational product or interpretation of the participantsafety data or study results

19. History of malignancy within the past five years, except completely excised basalcell or squamous cell carcinoma of the skin, or cervical carcinoma in situ at leasttwo years prior to screening

20. Participation in another interventional clinical trial during trial participation orwithin 30 days prior to the IMP dosing or planned dosing

21. History of alcoholism or drug addiction within one year of screening. Substance usedisorder will be an exclusion criterion, at investigator's discretion.