MoonLake's Sonelokimab Shows Promise in Palmoplantar Pustulosis Phase 2 Trial, Advances Toward BLA Submission
Key Insights
MoonLake's sonelokimab demonstrated clinically meaningful and statistically significant benefit in the Phase 2 LEDA trial for palmoplantar pustulosis (search), achieving a 64% mean reduction in disease severity at week 16.
The company reported positive interim data from multiple clinical trials, including 46% of adolescent patients achieving HiSCR75 response in the VELA-TEEN trial for hidradenitis suppurativa (search).
MoonLake confirmed a Type B meeting with the FDA scheduled for December 15, 2025, to discuss the adequacy of clinical evidence for a Biologics License Application submission planned for Q3/Q4 2026.
MoonLake Immunotherapeutics announced positive results from its Phase 2 LEDA clinical trial evaluating sonelokimab in palmoplantar pustulosis (search) (PPP), marking a significant milestone for the investigational Nanobody® in treating a condition with no currently approved therapies. The company also reported encouraging interim data from multiple ongoing trials and confirmed regulatory discussions with the FDA regarding its planned Biologics License Application.
Phase 2 LEDA Trial Demonstrates Efficacy in PPP
In the Phase 2 LEDA clinical trial, sonelokimab demonstrated clinically meaningful and statistically significant benefit in patients with PPP. Patients treated with sonelokimab achieved a mean percent change from baseline in the Palmoplantar Pustular Psoriasis Area and Severity Index (PPPASI) of 64% at week 16. Additionally, 39% of patients achieved a ≥75% reduction in the PPPASI (PPPASI75), suggesting that sonelokimab could provide clinically meaningful improvements in this debilitating condition.
The safety profile of sonelokimab in the LEDA trial was consistent with previous trials with no new safety signals detected. Based on these results, MoonLake expects to commence a Phase 3 clinical trial in PPP in Q3 2026.
PPP is characterized by the development of blister-like pustules within erythematous, scaly plaques on the palms and soles of the feet. Patients frequently experience significant pain, burning, and itching sensations that can be debilitating and impair their ability to work, sleep, or perform other activities of daily living. Currently, the treatment of PPP is challenging with a significant unmet need for novel therapies.
Positive Interim Data from Hidradenitis Suppurativa Trials
MoonLake reported encouraging interim analyses from its hidradenitis suppurativa (search) (HS) clinical program. An interim analysis of long-term data from the Phase 3 VELA-1 and VELA-2 trials in adult patients with HS showed that sonelokimab demonstrates continuous clinical improvement and potentially competitive advantages beyond the week 16 primary endpoint.
The VELA-TEEN clinical trial, a Phase 3 study evaluating sonelokimab in adolescent HS patients, showed promising results in its interim analysis. Forty-six percent of patients achieved a HiSCR75 response at week 16 (n=11). The trial is expected to enroll a total of 30-35 patients and topline results are expected to become available in 2026.
FDA Meeting Scheduled for BLA Discussions
MoonLake confirmed a Type B meeting with the FDA, scheduled to be held on December 15, 2025, to discuss the adequacy of the current clinical evidence package of sonelokimab in HS to support a Biologics License Application (BLA). The meeting minutes are expected within the following 30 days, and the company plans to submit its BLA in Q3/Q4 2026.
Comprehensive Clinical Development Program
Sonelokimab is being evaluated across multiple inflammatory diseases with significant unmet medical needs. The investigational Nanobody® inhibits IL-17A and IL-17F (search) by inhibiting the IL-17A/A, IL-17A/F, and IL-17F/F dimers that drive inflammation.
The company's clinical pipeline includes ongoing Phase 3 trials in psoriatic arthritis (search) (IZAR-1 and IZAR-2) and Phase 2 trials in axial spondyloarthritis (search) (S-OLARIS). In previous trials, sonelokimab has demonstrated significant efficacy, including approximately 60% of patients with psoriatic arthritis achieving an American College of Rheumatology (ACR) 50 response and Minimal Disease Activity at week 24 in the Phase 2 ARGO trial.
Strong Financial Position Supports Development
As of September 30, 2025, MoonLake held cash, cash equivalents and short-term marketable debt securities of $380.5 million. The company expects its cash resources, together with committed capital under a previously announced debt facility with Hercules Capital, to be sufficient to fund its operating expenses and capital expenditure requirements into the second half of 2027.
Research and development expenses for the third quarter of 2025 were $60.6 million, compared to $49.8 million in the previous quarter. The increase was driven by expenses with contract research organizations and contract manufacturing organizations, as well as consulting expenses and personnel-related costs to support the ramp-up of clinical trials and preparations for the anticipated BLA submission.
Upcoming Clinical Milestones
MoonLake has outlined a catalyst-rich roadmap for the next 12 months, including several key milestones:
- Q1 2026: Primary endpoint readout of the Phase 2 S-OLARIS trial in axial spondyloarthritis
- Q2 2026: 52-week data from the VELA-1 and VELA-2 trials in HS
- Q2 2026: Primary endpoint readout of the Phase 3 IZAR-1 trial in psoriatic arthritis
- Q2 2026: Primary endpoint readout of Phase 3 VELA-TEEN trial in adolescent HS
- H2 2026: Primary endpoint readout of the Phase 3 IZAR-2 trial in psoriatic arthritis
The company's focus on inflammatory diseases with major unmet needs, including hidradenitis suppurativa (search), psoriatic arthritis (search), axial spondyloarthritis (search) and palmoplantar pustulosis (search), addresses conditions affecting millions of people worldwide with a large need for improved treatment options.