Royalty cash funds Genmab's biotech pivot
- Genmab still depends heavily on DARZALEX royalties, but it is building its own drug sales engine.
- EPKINLY sales reached $312 million in the first half of 2026, growing 48% year over year.
- Rina-S has moved faster than expected, with pivotal ovarian cancer data due in late 2026.
- The Merus deal added petosemtamab, but it also brings $5.5 billion of acquisition debt.
- The big test is whether new owned products can offset a DARZALEX royalty decline starting in 2029.
A cash-rich pivot with trial risk
Genmab's story is changing. For years, much of the money came from royalties on partner-sold drugs, especially DARZALEX. Now the company wants to become a full biotech, meaning it develops drugs, runs trials, and sells more products itself.
The bull case is that the old royalty stream gives Genmab time and cash to build the new model. Commercial execution is strong. EPKINLY reached $312 million in sales in the first half of 2026, up 48% from a year earlier. The FDA also removed the 24-hour hospital stay recommendation after the first full dose in third-line or later DLBCL, a type of lymphoma, which makes doctors more willing to use it outside big hospitals.
The next proof points are clinical, with massive readouts in late 2026. Petosemtamab gives Genmab another late-stage cancer drug. Management confirmed that the frontline head and neck cancer trial expansion to 700 patients was a pre-planned move for global filing subgroups, rather than a reaction to weak early data. The company is also expanding petosemtamab into colorectal cancer with two new Phase III trials.
The bear case is concentration and timing. DARZALEX royalties are still the main profit base, and Genmab says U.S. daratumumab patents expire in 2029, when royalties should begin to fall materially. The stock needs new product sales and late-stage data to arrive before that royalty cliff matters.
Royalties pay for owned launches
Genmab makes money in several ways. The biggest is royalties, which are payments based on sales of drugs that partners sell. In 2025, royalties were $3.102 billion out of $3.720 billion of total revenue, or about 83% of revenue.
The faster-growing part is direct and partnered product sales. Genmab records EPKINLY net product sales in the U.S. and Japan under its AbbVie partnership. It also records or shares economics from Tivdak, depending on the country. In the first half of 2026, EPKINLY reached $312 million in sales, while Tivdak reached $84 million.
The Merus acquisition pushes Genmab further toward owning more of its future. It added petosemtamab, BIZENGRI royalties, and antibody technology platforms. The tradeoff is financial. Genmab took on $5.5 billion of loans and notes for the deal, with $4.1 billion effectively fixed at about a 6.6% interest rate, and management wants gross leverage below 3x by the end of 2027.
The drugs that matter
DARZALEX royalties
DARZALEX is sold by J&J, while Genmab receives royalties. It is the main cash source today, but U.S. patent rights on daratumumab expire in 2029.
EPKINLY
EPKINLY is a bispecific antibody, a drug that binds both cancer cells and immune cells. Sales reached $312 million in the first half of 2026, and the looser hospital-use language aids community adoption.
Tivdak
Tivdak is an antibody drug conjugate, meaning an antibody carries a cancer-killing payload. First half 2026 sales reached $84 million, and Genmab is taking more responsibility outside the U.S. and China.
Rina-S
Rina-S is a late-stage antibody drug conjugate aimed first at ovarian and endometrial cancers. The Phase III RAINFOL-02 trial in platinum-resistant ovarian cancer finished enrollment early, moving pivotal data into late 2026.
Petosemtamab
Petosemtamab came with the Merus deal and is in Phase III studies for head and neck cancer. Genmab is also launching two new Phase III trials for the drug in colorectal cancer.
Acasunlimab
Acasunlimab remains one of Genmab's prioritized Phase III programs. It adds another late-stage shot on goal, but like any cancer trial asset, it can lose value quickly if survival or response data disappoint.
BIZENGRI
BIZENGRI was added through Merus and gives Genmab another royalty medicine. Genmab has said the added BIZENGRI royalties are not expected to be material.
Revenue still starts with royalties
The mix uses 2025 revenue by type from Genmab's Annual Report Note 2.1. Royalties are the clear majority, so the company is still exposed to partner sales and patent timing even as owned product sales grow.
What could break the thesis
DARZALEX royalty cliff
High impact · High oddsDARZALEX royalties are the main profit base. Genmab says U.S. daratumumab patent rights expire in 2029 and royalties should begin to decline materially after that. If EPKINLY, Rina-S, Tivdak, and petosemtamab do not scale fast enough, earnings power could fall.
Rina-S data miss
High impact · Medium oddsRina-S is one of the main owned assets meant to replace future royalty pressure. The ovarian cancer Phase III trial enrolled faster than expected, which is good for timing but does not reduce the need for strong efficacy and safety. A weak RAINFOL-02 readout would hurt the owned-pipeline story.
Petosemtamab competitive pressure
Medium impact · Medium oddsGenmab bought Merus in part for petosemtamab. In head and neck cancer, the drug faces intense competitive pressure from Johnson and Johnson's amivantamab, which is pursuing accelerated approval ahead of Genmab's Phase III readouts. If petosemtamab cannot show convincing safety and efficacy differentiation, it could lose market share.
EPKINLY confirmatory risk
Medium impact · Medium oddsEPKINLY is growing, but the EPCORE DLBCL-1 monotherapy trial missed its overall survival endpoint. Overall survival means whether patients lived longer, not only whether tumors shrank. Management pointed to COVID-19 and other bispecific drugs as factors, but regulators may still focus on the miss.
Debt and integration load
Medium impact · Medium oddsThe Merus deal added $5.5 billion of debt and integration work. Genmab says $4.1 billion is effectively fixed at about a 6.6% interest rate and targets gross leverage below 3x by the end of 2027. If trials cost more, launches slip, or integration charges rise, that deleveraging plan becomes harder.
In one breath
What does Genmab actually do?
Genmab develops antibody drugs, mostly for cancer. It also earns royalties when partners sell medicines that use Genmab science, with DARZALEX being the biggest example.
Why is DARZALEX so important to Genmab?
DARZALEX royalties are the largest part of revenue and help fund Genmab's pipeline. The risk is that U.S. patent rights on daratumumab expire in 2029, when those royalties are expected to decline materially.
What is the main bull case for GMAB stock?
The bull case is that Genmab uses royalty cash to build a stronger owned drug business. EPKINLY is already growing fast, and late 2026 data for Rina-S, petosemtamab, and EPKINLY could widen the future revenue base.
What should investors watch in 2026?
The biggest items are Rina-S ovarian cancer data, petosemtamab head and neck cancer data, and EPKINLY first-line DLBCL data due in late 2026. Investors should also watch whether Genmab keeps lowering leverage after the Merus acquisition.
