Kodiak Sciences shares more than doubled Monday after its lead eye-disease drug Zenkuda met the primary endpoint in a pivotal Phase 3 study while allowing more than half of treated patients to stretch dosing to once every six months. The DAYBREAK results move the precommercial biotechnology company closer to a planned regulatory filing and revive a program that Kodiak temporarily abandoned three years ago after setbacks in other late-stage trials.
Kodiak said both Zenkuda, also known as tarcocimab tedromer, and its separate experimental therapy tabirafusp alfa tedromer, or KSI-501, achieved non-inferior vision gains compared with aflibercept after one year in patients with wet age-related macular degeneration. Non-inferiority means the drugs met a prespecified statistical threshold showing their effect on vision was not meaningfully worse than the active comparator. Kodiak previously said the DAYBREAK study enrolled approximately 690 patients.
The market reaction was immediate. Kodiak shares were trading around $79.35 shortly before 11 a.m. Eastern time, up roughly 145% on the session and at a new 52-week high. The size of the move reflects more than a successful clinical endpoint: DAYBREAK was the final anticipated Phase 3 study in the Zenkuda program and provides Kodiak with the additional wet-AMD durability evidence it has been seeking ahead of a planned biologics license application.
Durability Gives Zenkuda Its Strongest Commercial Argument
The most consequential result was not simply matching aflibercept on vision. After four monthly loading doses, Zenkuda patients could be treated at individualized intervals ranging from every four weeks to every 24 weeks depending on disease activity, with retreatment triggered by retinal fluid. At the one-year point, 54% of patients had reached the 24-week interval under those relatively strict “treat-to-dryness” criteria.
That dosing result matters in a market where reducing the number of injections has become a major competitive objective. Regeneron’s Eylea HD, an 8-milligram formulation of aflibercept, is currently approved for wet AMD at intervals of eight to 16 weeks following its initial loading doses, with dosing as far apart as every 20 weeks permitted after one year of successful response. Kodiak’s 24-week result therefore pushes beyond the longest labeled Eylea HD interval, although the comparison should not be treated as a head-to-head superiority result. DAYBREAK evaluated Zenkuda against aflibercept under the study’s own comparator regimen, not directly against an Eylea HD every-20-week strategy.
Safety also strengthened the readout. Kodiak reported no cases of intraocular inflammation among Zenkuda-treated patients and a 0.5% rate of cataract adverse events, compared with a 0.9% cataract rate in the aflibercept group. Tabirafusp-ted produced a 0.4% intraocular-inflammation rate and no cataract adverse events. Kodiak characterized the safety of both experimental treatments as consistent with aflibercept, though the results remain topline data and the therapies have not been approved.
The clean Zenkuda safety result carries additional significance because tarcocimab has had an unusually difficult development history. In July 2023, Kodiak announced that its GLEAM and GLIMMER Phase 3 trials in diabetic macular edema had failed to establish non-inferior vision gains versus aflibercept, with an unexpected cataract imbalance contributing to the misses. Kodiak initially decided to discontinue further development even though its DAYLIGHT trial in wet AMD had met its primary endpoint. The company reversed course later that year after another Phase 3 study succeeded and discussions with U.S. regulators established a potential path forward using an enhanced commercial formulation.
Kodiak Now Moves Toward a Multi-Indication Filing
With DAYBREAK completed, Kodiak plans to submit a biologics license application for Zenkuda in the fourth quarter covering wet AMD, diabetic retinopathy and retinal vein occlusion. The submission is expected to draw on five successful Phase 3 studies: DAYBREAK and DAYLIGHT in wet AMD, GLOW1 and GLOW2 in diabetic retinopathy, and BEACON in retinal vein occlusion. Regulatory submission does not guarantee approval, but the DAYBREAK result removes one of the largest outstanding clinical uncertainties surrounding Kodiak’s lead program.
The KSI-501 portion of DAYBREAK was positive but carries a different strategic message. The bispecific drug, designed to inhibit both VEGF and the inflammatory cytokine IL-6, met its vision primary endpoint with a p-value of 0.0036 and an anatomical secondary endpoint with a p-value below 0.0001. Kodiak did not report superiority over aflibercept in the broad wet-AMD population, however, and said it will conduct post-hoc analyses to determine whether particular patient subgroups derive greater benefit from IL-6 inhibition.
That leaves diabetic macular edema as an important test of whether the added mechanism can produce a clinically differentiated result. Kodiak has already begun enrolling the roughly 910-patient Phase 3 ALTO study, which is specifically designed to test whether tabirafusp-ted can demonstrate superiority over aflibercept in that disease.
Kodiak will also have to manage the financial transition from clinical development toward a possible commercial launch. The company finished June with $125.9 million in cash and cash equivalents after posting a $65.6 million second-quarter net loss, including $56.1 million of research-and-development expense. Management said at the time that existing cash was expected to support current and planned operations into 2027.
For Zenkuda, attention now moves from whether the drug can produce another successful Phase 3 readout to what regulators make of the full five-study package. Kodiak’s planned fourth-quarter filing, the scope of any accepted dosing label and the FDA’s assessment of the program’s efficacy and safety record will determine whether the six-month durability demonstrated in DAYBREAK can become a commercial advantage rather than simply a clinical-trial result.