Genmab A/S (GMAB)

How it makes money

Most revenue is royalty income: a contractual percentage of what Johnson & Johnson and Novartis book selling DARZALEX and Kesimpta, which Genmab receives without bearing the cost of manufacturing, marketing or a sales force for those drugs. A smaller and faster-growing slice is net product sales from EPKINLY/TEPKINLY, which Genmab commercializes itself in some territories. The royalty model keeps margins very high but ties most of Genmab's fortunes to a single antibody it does not control commercially.

Revenue by segment

Genmab's royalty stream is protected by patents on daratumumab and by an exclusive license that bars Genmab itself from developing a competing antibody against the same CD38 target. That protection is time-limited: the relevant patents begin expiring in the late 2020s and early 2030s across the US, Europe and Japan, after which royalty rates and revenue are expected to decline.

Cancer treatment spending is not discretionary: patients and physicians do not defer chemotherapy or a myeloma drug because of the economy, and the drugs are largely covered by insurance or national health systems. Genmab's own revenue growth depends more on how many patients Johnson & Johnson's sales force reaches with DARZALEX and on Genmab's own launch execution for EPKINLY than on macroeconomic conditions.

Key risks

• Dependence on a single partnered drug — About two-thirds of revenue comes from DARZALEX royalties, a drug Genmab does not manufacture or sell itself. Genmab's fortunes hinge on decisions and execution by Johnson & Johnson, a company it does not control.
• Patent expiration reduces future royalties — Core daratumumab patents begin expiring around 2029 in the US and later in Europe and Japan; once they lapse, generic or biosimilar competition is expected to erode DARZALEX sales and Genmab's royalty income with them.
• Disputes with licensing partners — Genmab has previously entered binding arbitration with Janssen (Johnson & Johnson) over terms of the daratumumab license agreement, showing that even its most important partnership is not free of contractual disagreement.
• Manufacturing reliance on third parties — Genmab relies on a limited number of third-party contract manufacturers, some based in China, to produce the antibody drugs it sells directly, exposing it to supply disruption or geopolitical trade risk.

Top customers account for 66% of revenue

DARZALEX royalties from Johnson & Johnson alone accounted for about 66% of Genmab's 2025 revenue. A change in DARZALEX sales, pricing or J&J's marketing effort moves the majority of Genmab's income.