Gilead Sciences has agreed to acquire Germany-based Tubulis in a deal valued at $3.15 billion upfront, with up to $1.85 billion in additional milestone payments. The transaction provides Gilead with access to an antibody-drug conjugate (ADC) candidate advancing toward pivotal trials, alongside Tubulis’ underlying technology platforms.
The two companies previously entered into a partnership in 2024, under which Gilead paid $20 million upfront and committed up to $415 million in milestone payments to collaborate on an ADC program. This agreement followed earlier industry interest in Tubulis, including a collaboration with Bristol Myers Squibb valued at $22.7 million. Tubulis also raised €344 million (approximately $401 million) in a Series C financing round last year to support development of its pipeline.
The acquisition continues a period of dealmaking for Gilead, which has recently agreed to pay $7.8 billion for Arcellx and $1.67 billion for Ouro Medicines. The company’s activity follows comments made by CEO Daniel O’Day earlier this year, when he stated that Gilead was approaching transactions from a “position of strength.”
Tubulis’ lead asset, TUB-040, is a NaPi2b-targeting topoisomerase-I inhibitor ADC currently in Phase 1b/2 development for platinum-resistant ovarian cancer and non-small cell lung cancer. Clinical data reported last year showed a 59% overall response rate in platinum-resistant ovarian cancer, supporting plans to advance into pivotal studies while also exploring earlier lines of treatment and additional tumor types.
The program has drawn attention due to prior challenges in targeting NaPi2b with ADCs. Over the past decade, companies including Roche, Mersana Therapeutics and Zymeworks discontinued or paused similar programs, often citing insufficient clinical outcomes. TUB-040’s results have been presented as evidence that Tubulis’ platform may improve the therapeutic window by balancing efficacy with tolerability.
Gilead intends to support further clinical development of TUB-040 and incorporate Tubulis’ technology into its oncology efforts. Following the acquisition, Tubulis will operate as a dedicated ADC research and development organization within Gilead, with its Munich site serving as a center for ADC innovation. The deal is expected to close in the second quarter of this year.
In addition to TUB-040, Gilead highlighted another candidate, TUB-030, which has shown early clinical activity across multiple solid tumor types. The company has indicated that prior collaboration with Tubulis provided insight into its platform and capabilities.
Daniel O’Day described the transaction as “a significant milestone in Gilead’s progress in oncology.” He also noted, in paraphrased remarks, that earlier joint work between the companies contributed to confidence in Tubulis’ research approach and pipeline.
Gilead has an established presence in the ADC space, stemming in part from its 2020 acquisition of Immunomedics for $21 billion, which included the anti-TROP-2 ADC Trodelvy. However, the company has encountered setbacks, including the withdrawal of Trodelvy from the bladder cancer market following results from a confirmatory Phase III trial that did not meet expectations. The therapy remains approved for other breast cancer indications.
The Tubulis acquisition forms part of Gilead’s broader strategy to expand its oncology portfolio. In addition to its recent oncology-focused deals, the company has also pursued assets in immunology and inflammation, including the acquisition of Ouro Medicines and its T cell engager programs.
Strategic Importance of the Tubulis Acquisition
The acquisition underscores the growing importance of Tubulis’ ADC technology in oncology. By integrating Tubulis into its portfolio, Gilead aims to accelerate the development of targeted cancer treatments that deliver potent drugs directly to tumor cells while minimizing damage to healthy tissue.
Antibody-drug conjugates (ADCs) have become one of the most promising areas in oncology due to their precision-targeting capabilities. By combining a monoclonal antibody with a potent cytotoxic agent, ADCs can selectively attack cancer cells while minimizing harm to healthy tissues.
This targeted approach is helping to redefine how cancer therapies are developed, with several ADC-based drugs already achieving regulatory approval and commercial success. The growing interest in this field has led to increased partnerships, licensing deals, and acquisitions across the biotech industry.
