Gilead Sciences agreed to buy German biotech Tubulis for $3.15 billion upfront, with up to $1.85 billion more tied to milestones, in a deal focused on next-generation antibody-drug conjugates (ADCs), the companies said. The acquisition is positioned to broaden Gilead’s oncology ADC pipeline, building on Tubulis’s ADC platform and an internal roadmap that centers on improved tumor targeting and dosing potential. The transaction follows other Gilead moves in 2026, including deals to acquire Arcellx and Ouro Therapeutics, underscoring how Gilead is clustering growth around novel immuno-oncology and ADC modalities. For ADC investors and rivals, Gilead’s step-up highlights that big pharma is still willing to pay for differentiated linker/payload or engineering platforms as pivotal trial candidates approach later-stage testing.