Structural, nonclinical, and clinical features of ozoralizumab: A novel tumour necrosis factor inhibitor.

Tumour necrosis factor (TNF) inhibitors are currently the most widely used biological agents to treat rheumatoid arthritis. Ozoralizumab (OZR), a novel TNF inhibitor, is an antibody using variable heavy-chain domains of heavy-chain antibody (VHHs) and became the first VHH drug approved for the treatment of rheumatoid arthritis in September 2022. VHHs isolated from camelid heavy-chain antibodies can bind antigens with a single molecule. OZR is a trivalent VHH that consists of two anti-human TNFα VHHs and one anti-human serum albumin (anti-HSA) VHH. This review summarizes OZR's unique structural characteristics and nonclinical and clinical data. The clinical data outline the pharmacokinetics, efficacy, relationship between efficacy and pharmacokinetics, and safety of OZR, focusing on a Phase II/III confirmatory study (OHZORA trial).