Cementing its interest in antibody-drug conjugate technology, Merck & Co. has agreed to partner with Seattle Genetics to jointly develop and commercialise the latter’s ladiratuzumab vedotin worldwide. Alongside this, Merck was granted a license to commercialise Seattle Genetics’ HER2-positive breast cancer treatment Tukysa® (tucatinib) in regions outside of the US, Canada and Europe. The deals, which are worth up to US$4.5 B combined, represent another opportunity for Merck to diversify its pipeline beyond Keytruda and to relieve investors of their concerns regarding Merck’s over-dependence on the drug.