- SeaGen will add an experimental antibody drug to its expanding pipeline of cancer medicines, announcing Monday a deal with RemeGen to license a treatment the Chinese biotech company is developing for breast, bladder and stomach tumors.
- RemeGen's drug won't come to SeaGen cheap. The Seattle-based drugmaker is paying $200 million upfront to acquire the medicine, an antibody-drug conjugate targeting the HER2 protein, and has promised as much as $2.4 billion more in an array of milestone-based payments.
- RemeGen is one of a number of fast-rising China-based biotechs, companies that U.S.- and Europe-based pharmaceutical companies are increasingly turning to source promising new medicines. Last fall, RemeGen raised roughly $515 million in an initial public offering on the Hong Kong stock exchange, a sum that ranks among the industry's largest IPOs.
SeaGen is one of the top developers of antibody-drug conjugates, a type of medicine that combines a tumor-seeking antibody with a chemotherapy payload. Its flagship ADC Adcetris is approved for several types of lymphoma and, late in 2019, the company won Food and Drug Administration for its second ADC, called Padcev, for treating bladder cancer.
SeaGen's decision to turn to RemeGen for an ADC, then, is a notable vote of confidence in the Chinese company's drugmaking technology.
RemeGen's drug, called disitamab vedotin, is aimed at a protein called HER2 that's overexpressed in breast and other cancers and is the target of a number of approved drugs like Herceptin, Perjeta, Kadcyla and, most recently, AstraZeneca's Enhertu.
Enhertu is also an antibody-drug conjugate and has quickly become a cornerstone of AstraZeneca's plans in oncology after the British drugmaker paid $1.35 billion two years ago to license partial rights from Daiichi Sankyo. On Monday, AstraZeneca said treatment with Enhertu extended progression-free survival more than Perjeta in women with metastatic HER2-positive breast cancer.
Until Monday's deal with RemeGen, SeaGen lacked a HER2-targeting ADC, a gap in its pipeline now filled by disitamab vedotin. (SeaGen does have an approved oral drug that's designed to block HER2, called Tukysa.)
Disitamab vedotin is conditionally approved in China and SeaGen said clinical trials showed the drug showed signs of efficacy against breast, bladder and stomach cancers. SeaGen also noted the potential to combine RemeGen's drug with cancer immunotherapies targeting the PD-1 protein in bladder cancer.
Under the deal, SeaGen gains rights to RemeGen's drug in markets outside of Asia, as well as in Japan and Singapore. The Seattle company will lead global development and, should the drug win approval, pay RemeGen royalties in the high single digits to mid-teen percentages of net sales.