SLK is a ~40kDa humanized nanobody consisting of three domains that binds interleukin-17A (IL-17A), IL-17F, and human serum albumin. It has a unique mechanism of action that inhibits the inflammatory cytokines IL-17A and IL-17F, which are implicated in several autoimmune and inflammatory diseases. Unlike other IL-17 inhibitors, SLK can block all IL-17 pro-inflammatory dimers (IL-17A/A, IL-17A/F, and IL-17F/F). Its small size also enables tissue penetration. SLK is administered subcutaneously once every four weeks.
MoonLake has tested SLK across phase 2 trials in hidradenitis suppurativa (HS), psoriatic arthritis (PsA), and psoriasis (PsO), demonstrating leading clinical efficacy and a favorable safety profile. This positions SLK as a potentially best-in-class IL-17 inhibitor.