Zymeworks' $250M Ziihera milestone lifts Q3 and guidance, but the base business is still being built

The quarter in numbers

Zymeworks reported total revenue of $256.5 million for the third quarter ended September 30, 2026, against $27.6 million a year earlier. Net income was $173.7 million, compared with a net loss of $19.6 million in 3Q-2025. The release's own text label for that line reads "Net Loss", but the figures and narrative describe net income.

R&D expenses were $36.1 million (3Q-2025: $35.6 million). SG&A rose to $42.7 million from $14.1 million. Net other expense was $4.4 million, versus net other income of $3.8 million a year earlier.

This is a milestone-driven quarter rather than a run-rate one, and the company's own breakdown makes that plain.

What drove it: one milestone, thin royalties, a new commercial asset

The company said the revenue increase was primarily due to the $250.0 million milestone earned from Jazz following the U.S. approval of Ziihera for first-line HER2-positive advanced gastroesophageal adenocarcinoma (GEA) in August 2026. It was partly offset by the absence of a $25.0 million development milestone from Johnson & Johnson Innovative Medicine recognized in 3Q-2025.

Underlying royalties remain small. Royalty revenue from Jazz and BeOne Medicines was $2.3 million, driven primarily by Jazz's U.S. net sales of Ziihera. The first-line approval, which the company said expands the royalty opportunity, came too late in the quarter to change that picture.

The Theravance Biopharma acquisition closed on September 23, 2026, and contributed about $1.5 million of revenue for seven days of ownership. For YUPELRI, Zymeworks reported collaboration revenue up 4% YoY. Viatris-recognized U.S. net sales were $71.5 million, up 0.2% YoY. The company said doses pulled through the hospital channel grew at a double-digit rate YoY, which it described as continued underlying momentum. Dollar sales and dose volume are therefore moving at very different speeds, a gap the release does not explain.

Costs and the bottom line

The company said the SG&A increase was primarily driven by Theravance-related costs, including severance and transaction-related professional fees. Higher stock-based compensation also contributed, tied to 2026 equity awards, including leadership transition awards and the settlement of certain Theravance equity awards. The company called the primary earnings impact of the deal integration and transaction costs.

R&D was broadly flat. The company said lower ZW171 spending after that program's 2025 discontinuation, and reduced preclinical spending after IND-enabling work, were largely offset by employee costs from the Theravance deal.

The swing to net other expense reflects interest expense on the royalty-backed note with Royalty Pharma, executed in March 2026, and lower interest income from reduced investment balances. Looking ahead, the company expects $13 million to $15 million of annualized overhead and corporate costs to be eliminated post-closing.

Guidance and capital allocation

Zymeworks raised 2026 total revenue guidance to $337 million to $351 million from $278 million to $292 million. It raised Adjusted EBITDA guidance to $176 million to $190 million from $114 million to $128 million. By our arithmetic, that is $59 million added at both ends of the revenue range and $62 million at both ends of the EBITDA range. The company attributed the increase to business development execution and said guidance excludes any future transactions. It is also subject to expiration or termination of the HSR waiting period for the Roche collaboration, expected in the fourth quarter of 2026.

On funding, the company said it accessed $600 million of non-dilutive financing in 2026 through a non-recourse royalty-backed note and a non-recourse note. It put the weighted average cost of capital at under 10%. The financing supported the Theravance acquisition and buybacks, and the company said it has no current plans for additional equity issuances.

Zymeworks repurchased 534,381 shares for $14.0 million in Q3. Over nine months it bought 5,737,790 shares for $140.4 million, an average of $24.48 per share. Since August 2024 it has used $279.8 million to reacquire 12,940,827 shares at an average of $21.63. About 69.0 million shares were outstanding as of November 6, 2026.

Pipeline and regulatory catalysts

The company said Jazz's August 25 FDA approval covers two Ziihera-containing regimens in first-line HER2-positive GEA. It cited an ESMO guideline recommendation and a Category 2A NCCN recommendation. Zymeworks remains eligible for up to $190 million in additional global regulatory milestones tied to ex-U.S. GEA approvals from Jazz and BeOne.

Final HERIZON-GEA-01 analysis, presented October 23 at ESMO, showed Ziihera plus tislelizumab and chemotherapy with median overall survival of 27 months and a hazard ratio of 0.65 (95% CI: 0.52–0.80), improved from 0.72 at the first interim analysis. Ziihera plus chemotherapy reduced the rate of death by 24% versus trastuzumab plus chemotherapy.

On ZW209, the October 23 Roche agreement carries a $55 million upfront payment, a $40 million payment on Phase 1b initiation, and up to $718 million in further milestones. Royalties are tiered from high single digit to mid-teens. The release says Roche will fund the Phase 1a trial and handle later global development and commercialization.

Other data points include ZW191 in platinum-resistant ovarian cancer, with a 64.5% confirmed objective response rate at 6.4 mg/kg in high-grade serous disease. J&J's pasritamig combination showed a 73% PSA50 response rate at the recommended Phase 2 regimen.

What to watch next

The first checkpoint is HSR clearance for the Roche deal, since the raised guidance is explicitly conditioned on it. Next is the first full quarter of Theravance and YUPELRI contribution, alongside whether the $13 million to $15 million cost savings show up in SG&A as one-off integration costs fade.

Ziihera's first-line launch trajectory will show in Jazz-reported sales and Zymeworks' royalty line, which was only $2.3 million this quarter. Further milestones depend on ex-U.S. approvals. Zymeworks is not holding an earnings call, so the next management commentary should come at the R&D Day on February 11, 2027, in New York. ZW191 partnering is signaled by the company's reference to continued development "in partnership or through a strategic collaboration." The ZW1953 AML poster at ASH on December 13 is also due.