A Study to Evaluate the Safety and Efficacy of Dual Costimulation Blockade With VIB4920 and Belatacept for Prophylaxis of Allograft Rejection in Adults Receiving a Kidney Transplant

Open to people ages 18-70

• Recipients of a first renal transplant from standard criteria deceased, living unrelated or HLA non-identical living related donor.
• Recipients who are at low immunologic risk:
• No donor specific antibodies (DSA), and
• Negative cross-match testing.
• Recipients with up to date vaccination as per local immunization schedules.
• Male and female participants who agree to follow protocol defined contraceptive methods.

• Participants receiving an allograft from an ABO-incompatible donor.
• Participants treated with systemic immunosuppressive drug therapy for more than a total of 2 weeks within 24 weeks prior to informed consent form signature.
• Participants who have undergone lymphodepleting therapy.
• Participants with medical history of confirmed venous thromboembolism, arterial thrombosis, coagulopathy or known platelet disorders.
• Participants with risk factors for venous thromboembolism or arterial thrombosis, prothrombotic status.
• Participants requiring treatment with antithrombotic drugs (clopidogrel, prasugrel, warfarin, others).
• Participants requiring long-term systemic anticoagulation after transplantation, which would interfere with obtaining biopsies.
• Participants with any contraindication to kidney biopsy.
• Cytomegalovirus (CMV)-seronegative recipients of a CMV-seropositive donor kidney, or unknown CMV serostatus.
• Epstein-Barr virus (EBV)-seronegative or with unknown EBV serostatus.
• Receipt of live (attenuated) vaccine within the 4 weeks before screening.
• Participants with high potential of graft loss due to recurrence of underlying kidney disease.
• Prior solid organ transplant or potential to require a concurrent organ or cell transplant.
• Previous treatment with belatacept and cluster of differentiation 40 (CD40) or anti-CD40L agents.
• Use of B cell depleting therapy, non-depleting B cell directed therapy e.g., belimumab or abatacept within 1 year prior to enrolment.
• At screening blood tests any of the following:
• Aspartate aminotransferase (AST) > 2.5 × upper limit of normal (ULN)
• Alanine aminotransferase (ALT) > 2.5 × ULN
• Alkaline phosphatase (ALP) > 2.5 × ULN
• Total bilirubin (TBL) > 2 × ULN
• Hemoglobin < 75 g/L

• Neutrophils < 1.5 × 10⁹/L

• Platelets < 100 × 10⁹/L

• Participants with severe systemic infections, current or within the 2 weeks prior to transplant surgery.
• Positive test for chronic hepatitis B infection at screening or within the last 12 months.
• Positive test for hepatitis C virus antibody at screening or within the last 12 months.
• Positive test for human immunodeficiency viruses antibody at screening or within the last 12 months.
• History of or active tuberculosis (TB), or a positive QuantiFERON®-TB Gold test at screening, unless previously treated for latent tuberculosis.
• History of cancer, except as follows:
• In situ carcinoma of the cervix treated with apparent success with curative therapy > 12 months prior to screening; or
• Cutaneous basal cell or squamous cell carcinoma treated with apparent success with curative therapy.
• Lactating or pregnant females.