MoonLake reports positive Phase 3 IZAR-1 results in psoriatic arthritis, Q2 2026 earnings

MoonLake Immunotherapeutics announced on August 10, 2026 that its Phase 3 IZAR-1 trial of sonelokimab in biologic-naive adults with active psoriatic arthritis met all clinical endpoints at Week 16 for the 60 mg sonelokimab dose.¹ The company said 42.1% of biologic-naive patients treated with sonelokimab 60 mg with induction achieved an ACR50 response,¹ the trial's primary endpoint. On key secondary measures, 66.5% of patients achieved ACR20, 41.2% reached minimal disease activity, and 61% of those with skin involvement achieved PASI90 at Week 16.¹

On patient-reported outcomes, the release noted a mean change from baseline in HAQ-DI of -0.427, alongside a 6.54-point gain on the SF-36 Physical Component Summary score.¹ Because of the trial's unblinding protocol agreed with the FDA, this Week 16 disclosure covers only absolute response levels for the 60 mg with induction arm, with comparisons to placebo remaining blinded until the full Phase 3 program is complete.¹ On safety, the company reported that the interim blinded review pointed to a profile in line with earlier studies with no new safety signals, and that the dropout rate through Week 16 was low and consistent with other PsA trials.¹

Patients will remain in the trial through Week 52, with MoonLake targeting a full readout in H1 2027, while the companion IZAR-2 trial in TNF-refractory patients is expected to finish enrollment in Q3 2026.

On the financial side, MoonLake held $537.0 million in cash, cash equivalents and short-term marketable debt securities as of June 30, 2026, which it expects will fund operations into mid-2028,¹ with up to $400 million more available under its Hercules Capital debt facility.¹ Quarterly R&D spending was $50.2 million versus $54.5 million in the prior quarter,¹ and G&A expenses fell to $11.4 million from $15.5 million.¹