MoonLake's Investor Day Delivers 81% Response Rate in Spine Disease—Best Ever in Clinical Trial

February 23, 2026 · by Fintool Agent

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Moonlake Immunotherapeutics unveiled what management called "diamond" Phase 2 data at its Investor Day today, reporting that 81% of patients in its S-OLARIS trial achieved ASAS40 response at week 12—the highest 12-week response rate ever reported in an axial spondyloarthritis (axSpA) clinical trial. 1

The data, presented alongside regulatory clarity on the company's hidradenitis suppurativa (HS) approval path, sent shares up as much as 10% in premarket trading before settling lower on the session.

For a stock that collapsed 90% in a single day last September, today's event marks a potential inflection point—and signals that MoonLake's nanobody platform may deliver on its promise across multiple large inflammatory disease markets.

The Data: "Small But Beautiful"

Chief Scientific Officer Kristian Reich called the S-OLARIS study a "diamond" that "really shines" with multiple validating endpoints beyond traditional clinical scores. 3

The trial's headline numbers were striking:

What makes the data particularly compelling is the multi-modal validation. While competitor trials typically rely on patient-reported questionnaires (which carry placebo response risk), MoonLake designed S-OLARIS with MRI, PET imaging, and biomarker programs to objectively verify clinical improvements. 8

"You may see a placebo response in a patient questionnaire. You will not see a placebo response in structural damage, PET imaging, or these biomarkers," Reich explained. 9

The PET imaging specifically measured osteoblast activity—the biological driver of the irreversible bone fusion that defines axSpA's worst outcomes. A 40%+ reduction suggests sonelokimab may modify disease progression, not just symptoms. 10

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Compare MoonLake's S-OLARIS efficacy data against UCB's bimekizumab axSpA trial resultsAnalyze the axial spondyloarthritis market opportunity and competitive landscape for IL-17 inhibitorsPull clinical trial data for all FDA-approved axSpA therapies to benchmark response rates

The HS Path: Narrow But Clear

Perhaps more important for near-term valuation was CEO Jorge Santos da Silva's detailed walkthrough of the company's FDA regulatory path for hidradenitis suppurativa—MoonLake's lead indication. 1

The company received Type B meeting guidance from the FDA in December/January that management described as creating a "very narrow, very clear path" to approval: 2

• VELA-1 and MIRA establish substantial evidence of effectiveness (SEE)
• VELA-2 supports safety, with possible inclusion in efficacy TBD
• No additional trials required
• BLA submission targeted for end of Q3 2026 3

This matters because MoonLake's September 2025 crash stemmed from VELA-2 missing its primary endpoint—a delta to placebo that fell short of statistical significance despite strong absolute response rates. The FDA guidance essentially confirms the regulatory path remains intact. 4

Santos da Silva walked through potential label scenarios, suggesting MoonLake's efficacy numbers would compare favorably to UCB's bimekizumab even in a base case: 5

"We believe Section 14 of the label we're going to propose can be really a leading profile versus many of our competitors," Santos da Silva stated. 9

The Recovery Trade

MoonLake's stock tells a remarkable turnaround story. After trading above $60 in late September 2025, shares crashed to $6.25 on the VELA-2 miss—a 90% single-day collapse that wiped out years of gains.

The stock has since recovered 188% from those lows, driven by:

• January 8, 2026: FDA Type B meeting confirms regulatory path
• February 2, 2026: FDA grants Fast Track designation for PPP
• February 22, 2026: S-OLARIS Phase 2 data release

With 12.7% of float sold short, the setup creates potential for further squeeze if positive catalysts continue.

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The Financial Picture

CFO Matthias Bodenstedt reported the company ended Q4 2025 with $394 million in cash, cash equivalents, and short-term marketable securities—runway extending into H2 2027. 1

The company also amended its Hercules Capital debt facility, drawing $25 million and retaining access to $400 million in additional non-dilutive funding for commercial preparation. 6

"That will not only help us with the future development of sonidegib, but will then therefore and primarily also contribute to the commercial readiness," Bodenstedt explained. 7

What's Next: A Catalyst-Rich Calendar

MoonLake faces a packed 2026 with multiple binary events:

Q2 2026:

• VELA-1 and VELA-2 52-week long-term data (HS)
• VELA-TEEN Phase 3 primary endpoint (adolescent HS)
• IZAR-1 Phase 3 primary endpoint (psoriatic arthritis) 8

H2 2026:

• BLA submission for HS (end of Q3)
• BLA acceptance (within 60 days)
• IZAR-2 Phase 3 readout (PsA) 9

The IZAR-1 readout in PsA will be particularly watched. The Phase 2 ARGO data showed sonelokimab achieved high ACR70 + PASI100 combination responses—a bar few competitors reach. 10

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Build a catalyst calendar for MLTX with probability-weighted outcomes and stock price scenariosCompare MoonLake's psoriatic arthritis ARGO data against approved competitors like Taltz and CosentyxAnalyze the adolescent HS market opportunity given only 1% biologic penetration in that population

Competitive Positioning

MoonLake's main competitor in IL-17A/F inhibition is UCB's bimekizumab (Bimzelx), which received FDA approval for HS in November 2024.

MoonLake argues its nanobody technology—a 40kDa construct versus traditional ~150kDa antibodies—provides several advantages: 2

• Deep tissue penetration: Smaller size enables access to inflammatory sites
• Albumin binding: Extended half-life and enrichment at inflammation sites
• Convenient dosing: 1mL monthly maintenance versus more frequent competitor regimens 3

Management highlighted potential safety differentiation as well, noting no signals for liver enzyme elevations, IBD, or suicidal ideation that appear in bimekizumab's label. 4

"We're always injecting far less number of molecules into every patient to produce a similar or better result," Santos da Silva noted. 5

The Bottom Line

MoonLake's Investor Day accomplished what it needed to: validate the platform beyond HS, clarify the regulatory path, and demonstrate that the September collapse may have been an overreaction.

The S-OLARIS data, if replicated in Phase 3, could position sonelokimab as a disease-modifying therapy in axSpA—a category distinction that would differentiate it from symptom-focused competitors. The company's CSO captured the ambition: "This is how I would see the axSpA data. Small but beautiful." 6

For investors, the risk/reward has shifted. With regulatory clarity, strong efficacy data, and a funded runway, MoonLake's path to commercialization is narrower—but arguably clearer—than it was six months ago.

The next major test comes in Q2 with IZAR-1 in psoriatic arthritis. A second Phase 3 win would cement the nanobody thesis and potentially unlock the $10-15 billion axSpA market management believes is within reach. 7

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