Here's a fun thing about good drugs: sometimes they don't peak when you think they will. Oruka Therapeutics Inc. (NASDAQ: ORKA) on Wednesday reported positive week 28 outcomes from its Phase 2a clinical trial evaluating ORKA-001 for moderate-to-severe plaque psoriasis, and the headline is that patient responses kept improving six months after they received their final dose of the novel antibody.

That's not how every drug behaves. Many plateau. Some fade. ORKA-001, at least in this dataset, is doing the thing drug developers dream about.

Phase 2a Trial Demonstrates Deepening Efficacy

Data showed that 63.5% of treated patients achieved complete skin clearance, or PASI 100, at week 16. Solid number on its own.

But clinical improvements continued to deepen by week 28. PASI 100 response rates increased to 71.4%, and PASI 90 response rates climbed to 87.3%. The trial also maintained IGA 0/1 response rates at 84.1%.

Patients transitioning from the placebo group to receive the active drug at weeks 16 and 20 exhibited a similar pattern of improvement. Twelve weeks after their initial dose, 40% of these crossover patients achieved PASI 100, aligning closely with the active arm at the equivalent timepoint. In other words, the crossover data is doing exactly what you'd want it to do: confirming the signal rather than muddying it.

Consistent Safety Profile And Tolerability

ORKA-001 remains well-tolerated, demonstrating a safety profile consistent with the IL-23p19 monoclonal antibody class.

Between weeks 16 and 28, upper respiratory tract infections represented the only treatment-emergent adverse event affecting more than 5% of patients. Investigators reported two serious adverse events, a tibial fracture and a prostate cancer diagnosis in a patient with elevated baseline risk factors, but deemed neither related to the study drug.

The trial recorded zero injection site reactions and no negative impacts from anti-drug antibodies. Zero injection site reactions is the kind of detail that sounds boring until you remember patients have to actually take this stuff.

Upcoming Milestones For Oruka Therapeutics

The EVERLAST-A study will continue through 52 weeks to evaluate response durability, maintenance dosing, and long-term safety. Oruka Therapeutics plans to release this comprehensive long-term data for all patients in December 2026.

Additionally, the biotechnology company continues advancing its EVERLAST-B Phase 2b trial for ORKA-001. Market observers anticipate new data from this subsequent trial during the fourth quarter of 2026.

ORKA Price Action: Oruka Therapeutics shares were down 0.30% at $94.26 at the time of publication on Wednesday, according to market data.