MoonLake Immunotherapeutics, a biopharmaceutical company focused on novel treatments for immune-mediated diseases, announced on Thursday that it has received guidance from the U.S. Food and Drug Administration (FDA) regarding the clinical evidence approach for its drug Sonelokimab (SLK) in the treatment of Hidradenitis Suppurativa (HS). This guidance followed a Type B meeting request submitted by MoonLake to clarify the regulatory pathway.
Sonelokimab has undergone rigorous evaluation in more than 1,000 patients across several studies: the MIRA, VELA-1, and VELA-2 trials. These clinical programs collectively demonstrated significant efficacy of SLK across various key clinical endpoints, supporting the drug’s therapeutic potential in HS.
Specifically, data from the MIRA trial showed a 43% response rate at the 120mg dosage of SLK, representing a 29 percentage point advantage over placebo at week 12, with a highly statistically significant difference (p < 0.001). Similarly, VELA-1 met all its primary and key secondary endpoints, achieving statistical significance under all pre-specified analytical methods.
In the VELA-2 study, SLK also showed statistical significance with a 36% response rate at week 16 for the 120mg dose, corresponding to a 10 percentage point difference over placebo (p = 0.033). However, an unexpectedly high placebo response rate in this trial resulted in the primary composite endpoint narrowly missing conventional statistical significance (delta of 9% versus placebo; p = 0.053), limiting the strength of evidence from this study alone.
Given these mixed results from the VELA trials, MoonLake sought regulatory clarity through a Type B meeting with the FDA. During the engagement, the agency indicated that MoonLake might be able to demonstrate sufficient evidence of the drug’s effectiveness for approval without initiating additional clinical trials specifically for HS. The FDA also recommended that data from the VELA-2 trial should still be included in the forthcoming marketing application, particularly to inform safety evaluations regardless of its contribution to efficacy assessments.
MoonLake plans to continue progressing with the preparation of its Biologics License Application (BLA) for Sonelokimab, with submission targeted for the second half of 2026. This timeline aligns with the company's development milestones and regulatory expectations.
Separately, market interest has been heightened by reports that pharmaceutical giant Merck & Co., Inc. approached MoonLake in June 2025 with an acquisition offer exceeding $3 billion, underscoring the strategic value attributed to Sonelokimab and MoonLake's pipeline.
Following the FDA meeting announcement, MoonLake’s shares experienced a significant rally, with prices rising 27.55% to $14.40 during Thursday trading.
Key Points
- MoonLake Immunotherapeutics engaged FDA in a Type B meeting to discuss regulatory strategy for Sonelokimab in treating Hidradenitis Suppurativa.
- Clinical trial data from over 1,000 patients showed substantial benefits, with MIRA and VELA-1 trials meeting primary and secondary endpoints with strong statistical significance.
- VELA-2 trial demonstrated a positive trend but narrowly missed statistical significance in the primary endpoint due to an elevated placebo response.
- FDA indicated potential approval without requiring new clinical trials; however, VELA-2 data must be submitted for safety evaluation.
- MoonLake targets BLA submission for the second half of 2026 and has attracted significant acquisition interest from Merck.
Risks and Uncertainties
- Despite positive indications from the FDA, the VELA-2 trial’s borderline results inject uncertainty regarding the overall strength of the efficacy data package.
- The actual FDA approval depends on the final review of the BLA, and unexpected regulatory hurdles could arise.
- Potential delays or complications in the BLA preparation or submission process might impact the planned timeline.
- Market reactions, including stock volatility, can be influenced by ongoing clinical and regulatory developments uncertain in nature.