ORKA Stock Down 5% Despite Positive Week 28 Psoriasis Efficacy Data
Oruka Therapeutics ORKA announced positive week 28 data from an ongoing mid-stage study evaluating ORKA-001 in adults with moderate-to-severe plaque psoriasis. Treatment with the candidate continued to show deepening skin-clearance responses six months after the last dose. Despite the positive efficacy update, ORKA shares lost 4.9% on Wednesday, likely reflecting investor attention to the safety disclosures accompanying the readout.
ORKA-001 is an investigational half-life extended antibody designed to target IL-23p19, a validated pathway in plaque psoriasis. The phase IIa EVERLAST-A study enrolled 84 patients and randomized 3:1 to receive 600 mg of ORKA-001 or placebo at weeks 0 and 4. Patients initially assigned to placebo later crossed over to receive ORKA-001 at weeks 16 and 20, while the study continues through week 52 to evaluate durability and long-term safety. Per Oruka, the study is also intended to assess the potential for highly infrequent dosing.
In April 2026, Oruka reported positive week 16 results from the EVERLAST-A study. Among patients treated with ORKA-001, 63.5% achieved PASI 100, meaning complete clearance of psoriasis lesions, meeting the study’s primary endpoint. The study also showed positive results on key secondary endpoints, including 82.5% achieving PASI 90, reflecting at least a 90% skin clearance and 84.1% achieving an IGA score of 0/1, indicating clear or almost clear skin. These results established a strong efficacy baseline for assessing whether responses could be sustained after treatment stopped.
ORKA’s Psoriasis Study Week 28 Results in Detail
Per Oruka’s latest press release, efficacy continued to improve despite no additional dosing after week 4. At Week 28, PASI 100 increased to 71.4% (45 of 63 patients), up from 63.5% at week 16. PASI 90 also rose to 87.3% (55 of 63 patients), while IGA 0/1 remained high at 84.1% (53 of 63 patients). The continued improvement six months after the final dose suggests that responses may deepen over time even without additional treatment. Among patients who crossed over from placebo, 40% achieved PASI 100 at week 28, 12 weeks after dosing, which is broadly comparable to the 42.9% rate in the initially treated group at the equivalent time point.
Year to date, Oruka shares have skyrocketed 196.7% against the industry’s 1.9% decline.
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ORKA-001 remained generally well tolerated through week 28, with Oruka reporting a safety profile consistent with the IL-23p19 class. Between weeks 16 and 28, upper respiratory tract infection was the only treatment-emergent adverse event occurring in at least 5% of patients receiving ORKA-001, reported in 8% of patients. Two serious adverse events were reported during this period, including a tibial fracture and prostate adenocarcinoma in a patient who had elevated PSA at baseline, neither of which was considered related to ORKA-001. No injection-site reactions were observed, and no impact from anti-drug antibodies on safety, efficacy or pharmacokinetics was reported. The safety disclosures may have contributed to the share decline following the update.
ORKA's Ongoing Pipeline Development
Oruka expects to report 52-week EVERLAST-A results for all patients in December 2026. These longer-term data are expected to provide additional insight into the durability of ORKA-001 responses and further inform the potential for once- to twice-yearly dosing. In addition, the phase IIb EVERLAST-B study of ORKA-001 in moderate-to-severe plaque psoriasis has completed enrollment, with week 16 data expected in the fourth quarter of 2026. The data are intended to support initiation of a phase III program for the candidate in the first half of 2027.
Another clinical-stage pipeline candidate is ORKA-002, a half-life extended IL-17A/F monoclonal antibody being developed for moderate-to-severe plaque psoriasis and hidradenitis suppurativa (HS). The company’s phase II ORCA-SURGE study of the candidate for psoriasis is expected to report week 16 data in the first quarter of 2027. Oruka has also initiated a separate phase II ORCA-SPLASH study of ORKA-002 for moderate-to-severe HS.
Beyond the two clinical-stage programs, ORKA-004, a half-life extended TL1A monoclonal antibody, is expected to enter clinical-stage development in the fourth quarter of 2026, while ORKA-003 remains in preclinical development.
Oruka Therapeutics, Inc. Price and Consensus
Oruka Therapeutics, Inc. price-consensus-chart | Oruka Therapeutics, Inc. Quote
ORKA’s Zacks Rank & Stocks to Consider
Oruka currently carries a Zacks Rank #3 (Hold).
Some better-ranked stocks in the biotech sector are Precigen PGEN, currently sporting a Zacks Rank #1 (Strong Buy), and AC Immune ACIU and Aldeyra Therapeutics ALDX, carrying a Zacks Rank #2 (Buy) each. You can see the complete list of today’s Zacks #1 Rank stocks here.
Over the past 60 days, estimates for Precigen’s 2026 bottom line have improved from a loss of 2 cents to earnings per share of 25 cents. Over the same period, earnings estimates for 2027 have risen from 25 cents to 86 cents. PGEN shares have increased 78% year to date.
Precigen’s earnings beat estimates in three of the trailing four quarters and missed in the remaining one, with the average surprise being 108.96%.
Over the past 60 days, estimates for AC Immune’s 2026 loss per share have narrowed from 84 cents to 60 cents. Over the same period, earnings estimates for 2027 remained unchanged at 17 cents. ACIU shares have lost 9.9% year to date.
AC Immune’s earnings beat estimates in each of the trailing four quarters, with the average surprise being 33.25%.
Over the past 60 days, loss per share estimates for Aldeyra Therapeutics have narrowed from 43 cents to 39 cents for 2026. Over the same period, estimates for 2027 loss per share have narrowed from 22 cents to 16 cents. ALDX shares have plunged 74% year to date.
Aldeyra Therapeutics’ earnings beat estimates in each of the trailing four quarters, delivering an average surprise of 29.25%.
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This article originally published on Zacks Investment Research (zacks.com).
