Shares of MoonLake Immunotherapeutics (NASDAQ:MLTX) climbed about 6.5% in premarket trading on Monday after the company said the U.S. Food and Drug Administration has granted Fast Track designation to sonelokimab (SLK) for the treatment of moderate-to-severe palmoplantar pustulosis (PPP).
The Fast Track decision follows encouraging data from the Phase 2 LEDA study and comes alongside recent FDA guidance that supports MoonLake’s clinical evidence strategy ahead of a planned Biologics License Application submission for SLK in hidradenitis suppurativa (HS) in the second half of 2026.
Fast Track status is intended to speed the development and review of medicines targeting serious conditions with significant unmet needs. For MoonLake, the designation enables more frequent engagement with the FDA, potential access to Accelerated Approval and Priority Review, and the option to submit sections of a future BLA on a rolling basis.
“This FDA decision marks an important milestone for MoonLake and for patients living with PPP,” said Dr. Jorge Santos da Silva, Founder and CEO of MoonLake Immunotherapeutics. “It underscores the significant unmet need in this debilitating disease and SLK’s potential to address it.”
The inflammation-focused biotech also announced it will host an Investor Day webcast on February 23, 2026. During the event, MoonLake plans to share the Phase 2 S-OLARIS data readout in axial spondyloarthritis (axSpA), provide updates on FDA feedback for HS, and outline key milestones expected in 2026.
Near-term catalysts include the primary endpoint readout from the Phase 2 S-OLARIS trial in axSpA in February 2026, 52-week data from the VELA trials in HS in the second quarter of 2026, and primary endpoint results from Phase 3 studies in psoriatic arthritis and adolescent HS slated for mid-2026.