Royalty growth, with a lawsuit attached
- Halozyme's main engine is ENHANZE, a drug delivery enzyme used in ten commercial partner products.
- Royalty revenue grew 43% year over year in Q1 2026, led by DARZALEX SC, VYVGART Hytrulo, and Phesgo.
- Management says about 66% of projected royalties from currently launched products are still expected from 2026 through 2032.
- New deals with GSK, Vertex, and Oruka support the push beyond ENHANZE into ADC and high-concentration drug delivery.
- The main overhang is the Merck patent case over subcutaneous Keytruda, plus execution risk in Hypercon and Surf Bio.
Royalties still have runway
Halozyme is a picks-and-shovels biotech. It does not need to build every drug itself. It licenses delivery technology to larger drug companies, then collects fees, milestones, and royalties when those partners succeed.
The core bull case got stronger after Q1 2026. Royalty revenue rose 43% year over year, and management kept its 2026 and 2026 to 2028 outlook. It also said about 66% of projected royalties from the ten approved products are still expected between 2026 and 2032. That matters because a key bear worry is that today's royalty wave fades too soon.
Capital returns are now part of the story. Halozyme announced a $1 billion share repurchase authorization through the end of 2028 and expects to buy back at least $400 million of stock in 2026. That can lift per-share results if the core business keeps growing.
The bear case is real. Merck litigation could cost money, distract management, or end badly. Hypercon and Surf Bio could also fail to copy ENHANZE's economics. The first Hypercon Phase I starts are now expected in the first half of 2027, so investors still need proof that the newer platforms can become commercial royalty machines.
Licensing shots, not selling drugs
ENHANZE is Halozyme's main product platform. It uses rHuPH20, an enzyme that temporarily opens space under the skin so large drug doses can be injected under the skin instead of through a long IV infusion. Partners pay upfront fees, development and sales milestones, buy bulk rHuPH20, and pay royalties on approved products.
The best part of the model is operating leverage. Royalties can grow as partners sell more of their drugs, while Halozyme does not carry the full cost of large global sales teams for those drugs. In Q1 2026, royalties were the biggest revenue stream and grew faster than total company revenue.
Product sales are the second stream. They include proprietary products like Hylenex and XYOSTED, bulk rHuPH20 sold to partners, and device-related product sales. This stream can jump around because partner ordering patterns can change from quarter to quarter.
Collaborative revenue is the lumpiest stream. It includes upfront fees and milestone payments tied to partner progress. New GSK, Vertex, and Oruka deals add promise, but the exact economics are still partly unknown. That is why the valuation case is good, not risk-free.
What Halozyme owns
ENHANZE
The core drug delivery platform. It powers ten commercial partner products and remains the main source of royalty growth.
DARZALEX FASPRO and DARZALEX SC
Janssen's multiple myeloma franchise is Halozyme's largest disclosed royalty driver. DARZALEX royalties were $129.0 million in Q1 2026.
VYVGART Hytrulo
argenx's autoimmune drug is a fast-growing ENHANZE product. Its royalties grew 119% year over year in Q1 2026.
Phesgo
Roche's breast cancer product adds another large ENHANZE royalty stream. It continues to grow, though not as fast as VYVGART Hytrulo.
Hypercon
Hypercon is a high-concentration drug delivery platform from the Elektrofi acquisition. Vertex and Oruka joined existing partners, but the first Phase I starts are now expected in the first half of 2027.
Surf Bio
Surf Bio is another high-concentration platform. It extends the long-term platform story, but it still needs clearer clinical timing and its first development partner.
Hylenex and XYOSTED
These are Halozyme's own marketed products. They help diversify revenue, but the company page story is still mostly about partner royalties.
Q1 revenue mix
Mix is based on Q1 2026 revenue in the March 2026 10-Q. Royalties are the key stream, but product sales can move with partner order timing and collaborative revenue can be milestone-driven.
What could break the thesis
Merck patent case goes against Halozyme
High impact · Medium oddsHalozyme filed a patent infringement lawsuit against Merck in April 2025 over alleged use of MDASE technology in subcutaneous Keytruda development. A bad ruling could weaken the IP story, add legal costs, or reduce leverage in future deals.
Partner sales slow down
High impact · Medium oddsHalozyme depends on partners such as Janssen, argenx, and Roche to sell the drugs that generate royalties. If DARZALEX SC, VYVGART Hytrulo, or Phesgo slow, Halozyme cannot fix that by hiring its own sales force for those products.
Hypercon does not scale into ENHANZE-like deals
Medium impact · Medium oddsHypercon has respected partners, including Vertex and Oruka, but it is still early. The first Phase I starts are now guided for the first half of 2027, so commercial proof is years away.
A Hypercon target is returned
Medium impact · Medium oddsThe Q1 2026 10-Q says one partner is evaluating the possible return of a target, with a decision expected by September 2026. If the target comes back without a similar replacement, Halozyme may need to assess acquired intangibles and goodwill from Elektrofi.
Supply chain bottlenecks
Medium impact · Low oddsHalozyme relies on a limited number of third-party manufacturers for bulk rHuPH20 and other key components. If supply misses partner needs, product sales and partner launches could be delayed.
IRA policy changes after 2028
Medium impact · Low oddsCMS final guidance in 2025 reduced the near-term risk for fixed-combination drugs. The risk is not gone because CMS may revisit policy for 2029 and beyond, which could affect long-term royalty streams.
In one breath
What does Halozyme actually do?
Halozyme licenses drug delivery technology to other drug companies. Its main platform, ENHANZE, helps some medicines move from IV infusion to faster under-the-skin injection.
Why are royalties so important for HALO?
Royalties are Halozyme's largest and fastest-growing revenue stream. In Q1 2026, royalty revenue rose 43% year over year, led by partner products such as DARZALEX SC, VYVGART Hytrulo, and Phesgo.
What is the Merck lawsuit about?
Halozyme says Merck used its patented MDASE subcutaneous delivery technology in the development of subcutaneous Keytruda. The outcome of the PTAB process and District Court case is one of the most important risks to watch.
Is Halozyme only an ENHANZE company?
ENHANZE is still the main value driver. Halozyme is also building Hypercon and Surf Bio, two high-concentration delivery platforms, but those platforms still need clinical starts and commercial proof.