Ustekinumab (Anti-IL-12/23p40 Monoclonal Antibody) in Patients With Leukocyte Adhesion Deficiency Type 1 (LAD1) Who Have Inflammatory Pathology

Lymphocyte adhesion deficiency type 1 (LAD1) is an autosomal recessive disorder of leukocyte function. Decreased expression of the \<=2 subunit of leukocyte integrins results in abnormal cell-cell and cell extracellular matrix adhesion. This disease is characterized by recurrent bacterial infections, impaired wound formation, and other aberrations of adhesion-dependent functions. The severe phenotype can be fatal, but patients with even moderate phenotypes are prone to infection and lose their teeth despite treatment. Ustekinumab is a monoclonal antibody directed against the p40 subunit of human interleukins IL-12 and IL-23. It is approved for treatment of moderate-to-severe plaque psoriasis, active psoriatic arthritis, and moderate-to-severe Crohn s disease. By binding the shared p40 subunit of IL-12 and IL-23, ustekinumab exerts clinical effects through interruption of the TH1 and TH17 cytokine pathways. Previous work at the NIH suggests that blockade of IL-17, which is highly expressed in the gingiva of people with LAD1, can reduce bacterial load and resolve inflammatory gingival disease. We have treated one patient with ustekinumab for 1 year; during this time, he had no serious infections and there was a dramatic resolution of his inflammatory lesions. Our goal is to explore the potential of ustekinumab as treatment for LAD1 inflammatory disease. The objective of this open-label, proof-of-concept study is to evaluate the safety and tolerability of ustekinumab in 10 patients with LAD1. Participants will receive 5 doses of ustekinumab via subcutaneous injection over the course of 1 year. They will be evaluated for adverse events, as well as the effect of the drug on inflammatory lesions and biomarker expression.