IL-17 is an immune-cell derived cytokine that is produced in response to infection by certain microorganisms. Upon binding to its receptor on various cell types found in tissues (e.g. keratinocytes, fibroblasts, and epithelial cells), it elicits downstream signals that orchestrate sustained tissue inflammation, with the aim of clearing the invading pathogen.
In autoimmune diseases, the immune system appears to over-react and mount strong immune responses in the absence of an obvious infectious event. Over the past two decades, it has become clear that IL-17 is a powerful driver of psoriasis, a skin disease that occurs in the absence of an obvious infectious event. Psoriasis manifests as erythematous plaques with thick scaling that can occur anywhere on the body. Symptoms include itching, bleeding, and pain; furthermore, the disease can lead to disfiguration and considerable psychological burden. According to the National Psoriasis Association, more than eight million Americans – and 125 million people worldwide – suffer from psoriasis. There is no cure for psoriasis.
Our lead therapeutic candidate, S011806, is an orally-available small molecule antagonist of IL-17 being developed initially for the treatment of psoriasis with the objective of achieving therapeutic benefit similar to that of the U.S. FDA approved injectable biologics, secukinumab and ixekizumab. We plan to initiate a Phase 1 clinical trial in healthy volunteers in the second half of 2021, followed by a Phase 1c trial in psoriasis patients in 2022.
Our IL-17 expertise has enabled us to build what we believe is the most comprehensive and functional DNA encoded library (DEL) for IL-17 small molecule inhibitors in the industry, and has resulted in the generation of multiple potential therapeutic candidates of IL-17 inhibitors with structural classes distinct from that of S011806. To take advantage of the depth of our IL-17 capabilities, we intend to advance two additional, structurally-distinct therapeutic candidates through IND-enabling studies, and to progress another candidate into clinical trials. We believe that advancing multiple platform-derived therapeutic candidates unlocks the ability to develop compounds with differentiated properties and has the potential to maximize the value of our IL-17 franchise.