Rosnilimab, formerly known as ANB030, is an antibody that binds PD-1 in an agonistic manner, leading to reduced T cell activity and anti-inflammatory effects in vivo. PD-1 is a key inhibitory immune checkpoint receptor expressed by activated T cells. PD-1 activity contributes to downregulation of T cell mediated immune responses in healthy individuals.

We believe insufficient PD-1 activity may be a key biological defect associated with human inflammatory diseases. Genetic mutations in the PD-1 pathway are associated with increased susceptibility to various inflammatory conditions (Okazaki and Honjo, Intern Immunol, 2017). We hypothesize that augmenting PD-1 signaling by rosnilimab treatment has the potential to broadly suppress human inflammatory diseases.

Rosnilimab was developed using AnaptysBio’s proprietary antibody discovery platform. We believe PD-1 agonist antibodies are challenging to discover due to the unique binding properties required to augment signaling through checkpoint receptors. Rosnilimab has been preclinically tested for key pharmacological properties (including binding potency, functional activity, epitope specificity, in vivo efficacy and pharmacokinetics) and manufacturability attributes (including expression and stability).

Through translational biology, we plan to focus the clinical development of rosnilimab upon certain human autoimmune diseases where PD-1 checkpoint receptor function may be under-represented. We presented ex vivo translational data demonstrating the activity of rosnilimab in peripheral blood mononuclear cells (PBMCs) from alopecia areata patients at the Festival of Biologics Conference in March 2020 (click here to download).

We are currently conducting a healthy-volunteer Phase 1 clinical of rosnilimab, which is designed to assess the safety, pharmacokinetics and pharmacodynamic activity of rosnilimab in single and multiple ascending cohorts, where top-line data in anticipated during the fourth quarter of 2021. We anticipate initiating Phase 2 trials of rosnilimab in alopecia areata in the fourth quarter of 2021.

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