HORIZON-GEA-01 Phase III Results — Zanidatumab
Phase III HORIZON-GEA-01 (partners Jazz and BeiGene) showed median progression-free survival >1 year and median overall survival >2 years in first-line metastatic/locally advanced HER2-positive GEA, with benefit across clinically relevant subgroups irrespective of PD-L1. An additional planned interim OS analysis is expected by mid-2026. Jazz plans a supplemental BLA submission (RTOR) in 2026 and zanidatumab has Breakthrough Therapy designation for HER2-positive GEA.
Regulatory Approvals and Commercial Upside
Zanidatumab received regulatory approvals as monotherapy for second-line biliary tract cancer in Canada and the UK. Zymeworks is eligible for near-term regulatory milestone payments: up to $440M tied to GEA approvals, $89M for a third indication, and up to $977.5M of commercial milestones — ~ $1.5B potential remaining under collaboration agreements.
Revenue Growth and Improved Profitability Metrics
Total revenue was $106.0M for FY2025 vs $76.3M in FY2024, an increase of ~39% year-over-year, driven mainly by clinical/regulatory milestones and option exercises. Net loss narrowed to $81.1M in 2025 from $122.7M in 2024 (an improvement of ~34%).
Royalty-Backed Note Financing with Royalty Pharma
Entered a nonrecourse royalty-backed note transaction providing $250M of nondilutive capital. Structure securitizes only 30% of zanidatumab royalties until repaid (Zymeworks retains 70% throughout), no stated interest rate like a traditional royalty loan, and all earned regulatory/commercial milestones remain retained by Zymeworks.
Pipeline Progress — ADCs, TCEs and IND Plans
ZW251 (GPC3 ADC) Phase I is actively enrolling ~100 patients across North America, Europe and APAC; dose-escalation started at 3.2 mg/kg. ZW191 dose-optimization/data maturing. IND submissions for multispecific programs ZW209 and ZW1528 remain on track for 2026. Pasritamig (partnered with J&J) showing encouraging Phase I safety/efficacy signals per ASCO GU.
Cost Discipline and Operating Expense Guidance
GAAP operating expenses decreased to $198.5M in 2025 from $213.4M in 2024 (~7% decrease), and company announced an adjusted gross operating expense framework of ~ $300M over three years ending 12/31/2028. Management expects 2026 adjusted gross operating expenses to be ~20% lower than 2025 (excluding acquisition-related expenses).
Share Repurchase Program and Capital Allocation Flexibility
Company retains the flexibility to continue opportunistic share repurchases; approximately $62.5M of the $125M authorized repurchase program has been utilized. Management frames repurchases as a capital-return lever given perceived discount between market price and long-term asset value.
Cash Runway Outlook
Cash, cash equivalents and marketable securities were $270.6M as of 12/31/2025. Management expects existing cash plus anticipated $440M regulatory milestone (GEA) and net proceeds from the royalty-backed note to fund operations beyond 2028 (this runway is contingent on execution of milestone payments and the repurchase plan).