Sonelokimab's Week 16 VELA Trial Results: A Paradigm Shift in Hidradenitis Suppurativa Treatment

MoonLake Immunotherapeutics' Phase 3 VELA program for sonelokimab in hidradenitis suppurativa (HS) has delivered compelling week 16 results, positioning the bispecific nanobody as a potential game-changer in a market ripe for innovation. With 838 patients enrolled across two identical trials, the data underscores sonelokimab's ability to outperform existing therapies while addressing critical unmet needs in HS care.

Efficacy: Meeting Primary Endpoints and Outperforming Placebo

The VELA-1 and VELA-2 trials evaluated a single 120mg dose of sonelokimab against placebo, with the primary endpoint of HiSCR75 (≥75% reduction in abscess and inflammatory nodule count, no increase in abscess or draining tunnel count). In VELA-1, sonelokimab achieved statistical significance (34.8% HiSCR75 vs. 17.5% placebo, p<0.001), while VELA-2 showed a 35.9% response rate versus 25.6% placebo. Though the composite strategy in VELA-2 narrowly missed significance (p=0.053), the treatment policy strategy—accounting for intercurrent events—revealed robust efficacy, with sonelokimab demonstrating 35% and 36% HiSCR75 in VELA-1 and VELA-2, respectively, as detailed in MoonLake's press release.

Key secondary endpoints further strengthened the case for sonelokimab: HiSCR50 (≥50% reduction) and patient-reported outcomes like pain reduction (30% of patients improved by 3 points on the Numerical Rating Scale) and quality-of-life metrics (HiSQOL, DLQI), as also reported by MoonLake. These results align with Phase 2 MIRA trial data, where sonelokimab showed a 29 percentage point delta over placebo on HiSCR75 at week 12, as reported in Dermatology Times.

Safety: A Favorable Profile with No New Signals

Sonelokimab's safety profile remained consistent with earlier trials, with no new adverse events reported, including no cases of suicidal ideation or behavior—a critical concern in HS patients, according to MoonLake's release. This aligns with its nanobody design, which enables deeper tissue penetration while minimizing systemic exposure compared to traditional monoclonal antibodies, as described in a PubMed review.

Market Context: Addressing a $15B Opportunity

The HS treatment market, valued at $841 million in 2025, is projected to reach $1.3 billion by 2035, driven by biologics targeting IL-17A (e.g., adalimumab, secukinumab) and emerging JAK inhibitors, per MoonLake's reporting. However, challenges persist: high placebo response rates in trials (25.6% in VELA-2), underdiagnosis, and a demand for therapies with fewer side effects, according to an IMARC report.

Sonelokimab's dual inhibition of IL-17A and IL-17F offers a mechanistic edge. A Medscape meta-analysis ranked sonelokimab highest for HiSCR-50 and HiSCR-75, outperforming adalimumab and bimekizumab in odds ratios (4.44 and 4.12 vs. placebo, respectively). Its nanobody platform also enables subcutaneous administration with a longer half-life, reducing dosing frequency compared to weekly or biweekly biologics, as previously described.

Regulatory Pathway and Long-Term Value

MoonLake has received positive feedback from the FDA and EMA for its regulatory strategy, with a Biologic License Application (BLA) anticipated in mid-2026, and the company is advancing sonelokimab in PsA, palmoplantar pustulosis, and axial spondyloarthritis, broadening its therapeutic footprint.

With at least 2 million HS patients in the U.S. alone and a projected $15 billion market for HS biologics by 2035, sonelokimab's approval could capture significant share, according to a Future Market Insights report. Its differentiated mechanism, combined with favorable trial outcomes and a robust safety profile, positions MoonLake to redefine HS treatment while unlocking long-term value for investors.

Conclusion

Sonelokimab's VELA trial results represent a pivotal step toward addressing HS's unmet needs. By combining superior efficacy, safety, and a novel nanobody platform, MoonLake is poised to disrupt a market dominated by established biologics. As the company advances toward regulatory approval and expands into new indications, the investment case for sonelokimab grows stronger, offering a compelling opportunity in a high-growth therapeutic area.