Shares of Oruka Therapeutics, Inc. (NASDAQ:ORKA) surged 45% following the release of Week 16 results from the EVERLAST-A Phase 2a study evaluating ORKA-001 in adults with moderate-to-severe plaque psoriasis.
The trial met its primary endpoint at Week 16. According to the company, 63.5% of patients who received ORKA-001 achieved PASI 100, indicating complete skin clearance. The same proportion, 63.5%, also achieved an Investigator Global Assessment (IGA) score of 0, defined as clear skin with no visible psoriasis.
EVERLAST-A is a randomized, double-blind, placebo-controlled Phase 2a study designed to assess ORKA-001, described as a half-life extended monoclonal antibody targeting IL-23p19. The trial enrolled 84 patients across 26 sites in the United States and Canada. Participants were randomized in a 3:1 ratio to receive either 600 mg of ORKA-001 administered at Week 0 and Week 4 or a matching placebo.
Key secondary outcomes also favored ORKA-001. The company reported that 83% of treated patients reached PASI 90 by Week 16, and 84% achieved IGA 0/1. By contrast, only one of the 21 participants randomized to placebo met these secondary endpoints. All reported response rates were calculated using non-responder imputation.
Safety data from the study were described as favorable and broadly consistent with the IL-23p19 therapeutic class. There were no serious treatment-emergent adverse events reported among participants receiving ORKA-001. One severe adverse event occurred in a participant assigned to placebo. The overall incidence of adverse events was similar between groups: 51% of ORKA-001 recipients experienced at least one adverse event compared with 57% of placebo recipients. The most frequently observed adverse event was upper respiratory tract infection, occurring in 19% of patients on ORKA-001 and 14% of those on placebo.
Separately, the company said updated Phase 1 pharmacokinetic and pharmacodynamic results continue to support the potential for once-yearly dosing of ORKA-001. Oruka indicated that longer-term data from the EVERLAST-A trial are expected in the second half of 2026.
Context and next steps
- The Week 16 results establish ORKA-001's ability to produce high rates of complete and near-complete skin clearance in this Phase 2a population.
- Further data from extended follow-up are anticipated in H2 2026, which will provide additional information on durability and longer-term safety.
- Investors reacted strongly to the Week 16 readout, reflected in the reported 45% increase in the company's share price.
While the data reported are limited to Week 16 and the Phase 2a cohort, the results provide a basis for evaluation of ORKA-001's efficacy and tolerability as development continues.