A Prospective and Retrospective Observational Study of Multidrug-Resistant Patient Outcomes With and Without Ibalizumab

Antiretroviral therapy (ART) for treatment of human immunodeficiency virus (HIV) has evolved tremendously over recent years. Newer medications have superior efficacy and tolerability, affording more convenient treatment regimens. The proportion of patients receiving antiretroviral (ARV) treatment that maintain viral suppression is approximately 85% in the United States. However, some patients may not be able to adhere to the prescribed ARV regimen or harbour strains of HIV that are resistant to most currently available therapies. Multi-drug resistant (MDR) HIV may be transmitted or result from incomplete viral suppression, which leads to accumulation of mutations in the viral genome over time. Patients with MDR HIV infection have significantly fewer available treatment options to construct a fully suppressive regimen. This ultimately results in shorter life expectancy, greater potential for transmission of MDR virus, increased morbidity and greater use of health resources. These comparisons are valid for the general population as well as people infected with non-MDR virus. Ibalizumab, a humanized IgG4 monoclonal antibody that binds to a conformational epitope on domain 2 of the extracellular portion of the CD4 receptor, belongs to a new class of ARVs, CD4-directed post-attachment HIV-1 inhibitors, Ibalizumab exhibits no known cross-resistance with other ARV medications. Ibalizumab was approved by the FDA on March 6, 2018 and is indicated in combination with other ARVs for the treatment of HIV-1 infection in heavily treatment-experienced adults with MDR HIV-1 infection failing their current ARV regimen. It has been available commercially from April 2018. The safety, efficacy and durability of response to ibalizumab treatment in combination with other ARVs have been demonstrated in clinical trials. This registry is designed to better understand the long-term efficacy and safety outcomes of MDR patients with and without ibalizumab in a real-world scenario.