MoonLake Immunotherapeutics (MoonLake Immunotherapeutics (MLTX)) stock is having a good Monday. The clinical-stage biotech released 52-week results from its Phase 3 VELA-1 and VELA-2 studies over the weekend, and investors like what they see. Shares were up over 20% in premarket trading.

The data, announced Sunday, showed that sonelokimab (SLK) — MoonLake's lead drug candidate for moderate-to-severe hidradenitis suppurativa (HS) — keeps working over the long haul. HS is a chronic inflammatory skin condition that causes painful lesions, and effective treatments are in high demand.

MoonLake also confirmed it's on track to submit a Biologics License Application (BLA) to the FDA by the end of September 2026. That's a big milestone for a company that's still in the clinical stage.

Strong One-Year Efficacy Across the Phase 3 Program

Pooled data from both VELA trials showed that 67.2% of patients treated with SLK achieved HiSCR75 at Week 52 — meaning they had at least a 75% reduction in inflammatory lesions. Even more impressive, 33.1% reached HiSCR100, a complete clearance of lesions. Results were consistent across both studies, which adds to the confidence.

Additionally, 26% of treated patients achieved an IHS4-100 response, indicating complete resolution of inflammatory lesions, including abscesses, nodules, and draining tunnels. That's a tough endpoint, so hitting it in a quarter of patients is noteworthy.

MoonLake said these long-term outcomes compare favorably with previously reported Phase 3 studies of competing HS therapies. In other words, sonelokimab appears to be generating higher response rates across several measures.

Quality of Life and Pain Scores Keep Improving

Clinical numbers are one thing, but do patients actually feel better? According to MoonLake, yes. Patients treated with SLK reported substantial gains in HS-specific quality-of-life measures. The average HiSQOL score improvement was 15.3 points in VELA-1 and 14.8 points in VELA-2. For context, that's a meaningful jump.

Broader dermatology quality-of-life assessments also improved, with 75% of patients in VELA-1 and 69.4% in VELA-2 achieving clinically meaningful responses. And nearly half of eligible patients experienced significant reductions in skin pain — defined as at least a three-point improvement from baseline.

Placebo Crossover and Teen Data Support Broader Potential

The trials also included a placebo crossover design. Patients who switched from placebo to SLK after Week 16 saw rapid improvements, with HiSCR75 response rates jumping by roughly 20 percentage points within four weeks. After 36 weeks of treatment, these crossover patients posted response rates comparable to those who had been on SLK from the start. That's a good sign for the drug's ability to work quickly and durably.

MoonLake also released interim Week 24 data from the Phase 3 VELA-TEEN study, which is testing sonelokimab in adolescents. About 68% of adolescent patients achieved HiSCR75, and 45% achieved HiSCR100. The company said no new safety concerns emerged in this younger population.

Overall, the safety profile across the VELA program remained consistent, with no new safety signals identified. That's always reassuring for a drug that's aiming for regulatory approval.

What's Next?

MoonLake expects the FDA to determine whether to grant Priority Review when it accepts the BLA. If all goes well, a commercial launch could happen in the second half of 2027. That's still a ways off, but for a biotech stock, having a clear path to market is a big deal.

For now, investors are cheering the durable efficacy data. MoonLake shares were up 20.15% at $23.08 in premarket trading Monday, according to market data. The stock has been volatile, but days like this remind everyone why they're paying attention.