Halozyme's royalty engine is running hot, with a patent fight and more debt alongside

The technology

Halozyme sells a way to make big-volume drugs injectable under the skin. Its ENHANZE platform uses a human enzyme, rHuPH20, to facilitate subcutaneous delivery of injected drugs and fluids. Partners pay an upfront fee, then milestones and royalties on sales. Halozyme says ENHANZE has reached more than a million patients through ten commercialized products, and it has added a second platform, Hypercon, that concentrates drugs to reduce injection volume.

The business is mostly royalties. In the second quarter, royalty revenue was $307.7 million of $481.0 million in total revenue, with Vyvgart Hytrulo and Darzalex Faspro doing most of the work. Halozyme also sells two products itself, Hylenex and Xyosted, and makes auto-injector combination products.

The odds

The approved royalty base has already crossed the clinical risk. The open questions are about the next waves. Halozyme says nine ENHANZE products were in development in the first quarter and it expects 13 by year-end, with approvals starting in 2029 or later, and Hypercon deals covering 17 targets with first approvals around 2030 and 2031.

Early programs fail often. The published base rates put the chance of approval at 7.9% from Phase I across all indications, with 28.9% of Phase II programs moving to Phase III. Late-stage partner products fare better: 57.8% of Phase III programs reach a filing, and 90.6% of filings are approved. Halozyme's own near-term exposure sits at that late end, including subcutaneous amivantamab, which has a pending supplemental application, and Takeda's TAK-881.

The money

Halozyme guides to 2026 revenue of $1.835 billion to $1.910 billion and adjusted EBITDA of $1.225 billion to $1.280 billion. It held only $231.9 million of cash and securities at June 30 but generates a lot of cash from operations, and it has been spending it. It repurchased $332.8 million of shares in the second quarter and has a $1.0 billion program through 2028.

Debt is rising. Convertible principal was $2.18 billion at June 30, and in September Halozyme priced $1.3 billion of 2033 notes, using part of the money to retire $151.7 million of 2027 notes and $220.0 million of 2028 notes. By my arithmetic, convertible principal would be about $3.1 billion after the deal closes.

The risks

The Merck dispute is the largest identifiable risk. The patent board has invalidated every challenged claim in four final decisions on Halozyme's MDASE patents, and Halozyme's suit over subcutaneous Keytruda is pending. A German appeal hearing is set for Nov. 19.

Second, concentration: two partner products drive most royalty growth. Third, a partner is evaluating the return of a target tied to the Elektrofi acquisition, with a decision expected by February 2027 and a possible impairment if it is returned. Fourth, leadership has turned over, with a new CFO in June and the chief operating officer's departure at the end of that month.

Our read

Halozyme is a high-margin royalty collector that has shown it can sign new platform deals faster than it promised. Revenue and profit are growing quickly, and the company is using the cash for buybacks, acquisitions and, now, more leverage.

The product risk is low for the established royalty streams and high for the new waves, which are years away. The Merck fight could matter more for the platform's reach than any single quarter. What would change this view is a ruling in New Jersey, the German appeal outcome, or the February partner decision. This is analysis, not advice.