The acquisition of Tubulis GmbH—Gilead Sciences’ latest of the year after buying Arcells and Ouro Medicines—brings into the fold a novel ovarian cancer candidate that has demonstrated promising mid-stage data.
The M&A train keeps chugging through biopharma, one bolt-on deal at a time. Tuesday’s move belongs to Gilead Sciences, which continued its own deal spree, snapping up German antibody-drug conjugate specialist Tubulis GmbH for $3.15 billion in cash plus up to $1.85 billion in potential milestone payments.
In a note to investors on Tuesday, analysts at RBC Capital Markets said the acquisition “represents a strategically sound bolt-on that addresses GILD’s oncology pipeline growth needs while securing differentiated next-gen ADC platform capabilities.”
Gilead CEO Daniel O’Day in a statement Tuesday called the acquisition “a significant milestone in Gilead’s progress in oncology.”
Under the terms of the agreement, Tubulis, with whom Gilead first partnered in December 2024, will operate as a dedicated antibody-drug conjugate (ADC) research and development organization within Gilead. The deal is expected to close quickly, in the second quarter of this year, Gilead said in its announcement on Tuesday.
Tubulis secured €344 million ($401 million) last October in a series C financing round to accelerate pivotal trials of lead candidate TUB-040, explore its use in earlier lines of treatment for ovarian cancer and expand into combination regimens, as well as new solid tumor indications. The asset is currently in Phase 1b/2 development for platinum-resistant ovarian cancer and non-small cell lung cancer.
In October 2025, Tubulis presented data for TUB-040 at the European Society for Medical Oncology (ESMO) Congress from a Phase 1/2a trial showing an average overall response rate of 59% in platinum-resistant ovarian cancer, “validating a potentially novel target,” according to RBC.
Gilead highlighted TUB-040 in addition to TUB-030, which the company said has “demonstrated promising initial clinical data across various solid tumor types.”
The company is already quite familiar with Tubulis’ ADC platform, having previously joined forces to discover and develop ADCs against an unnamed solid tumor target. This alliance “has given us strong conviction in their programs and research capabilities,” O’Day said.
Gilead is already a major player in the ADC space, though it has stumbled in recent years. In October 2024, the company pulled the ADC Trodelvy from the bladder cancer market after disappointing findings in the confirmatory Phase III TROPiCS-04 trial. Trodelvy is marketed for triple-negative breast cancer and HR+/HER2- metastatic breast cancer.
The Tubulis acquisition is Gilead’s latest move to bolster its cancer portfolio. In February, the California-based company swallowed another partner, the CAR T–focused Arcellx, ahead of the potential FDA approval of multiple myeloma hopeful anito-cel later this year. The $7.8 billion buyout price is 2026’s largest transaction to date.
Gilead has also been busy enhancing its immunology and inflammation pipeline. Last month, the company paid up to $2 billion to acquire Ouro Medicines and a pipeline of T cell engagers for inflammatory diseases. In a proposed three-way deal, Gilead hopes to shoulder the investment along with Galapagos.
