Gilead Sciences has announced a definitive agreement to acquire Munich-based Tubulis GmbH, a clinical-stage antibody-drug conjugate (ADC) specialist, in a deal valued at up to $5 billion. The transaction, structured as $3.15 billion in upfront cash at closing, with up to $1.85 billion tied to milestone payments, represents one of the most significant ADC acquisitions in recent memory and signals Gilead’s aggressive intent to dominate the next wave of oncology drug development.
Closing is expected in Q2 2026.
Building on an Existing Foundation
The acquisition does not come out of nowhere. The two companies began collaborating in 2024 through an option and license agreement valued at up to $465 million, which granted Gilead access to Tubulis’ proprietary ADC platforms. That early bet on Tubulis’s technology has now converted into a full acquisition, a pattern increasingly common among large pharma players who use structured partnerships as low-risk due diligence before committing to full ownership.
Tubulis’ lead asset, TUB-040, is a NaPi2b-directed topoisomerase-I inhibitor (TOPO1i) ADC currently in Phase 1b/2 development for platinum-resistant ovarian cancer and non-small cell lung cancer (NSCLC). A second program, TUB-030, is a 5T4-targeted ADC being developed across multiple solid tumor indications.
Early clinical data for TUB-040 drew considerable attention from the field. At ESMO, Tubulis presented data for TUB-040 showing a confirmed 50% overall response rate (ORR) and a 60% unconfirmed ORR across dose levels and irrespective of target antigen, results that were competitive with more mature datasets from leading TOPO1i ADCs. Analysts noted that if durability data continued to mature favorably and TUB-040 proves active in NSCLC, the program could complement Gilead’s existing Trodelvy franchise and its immuno-oncology lung initiatives.
A Strategic Fit for Gilead’s Oncology Ambitions
The acquisition significantly expands Gilead’s ADC capabilities by adding next-generation assets and platforms designed to more selectively deliver diverse payloads to tumors and maximize patient benefit. The Munich site will serve as a hub for ADC innovation within Gilead’s broader oncology infrastructure.
Gilead’s track record with ADCs provides context for the confidence underlying this deal. The company acquired Immunomedics in 2020 for $21 billion, gaining the cancer drug Trodelvy, which generated $1.4 billion in global sales during 2025, representing a 6% increase from the previous year. That investment has more than validated ADC-focused oncology as a core strategic pillar.
Third Acquisition of 2026
The Tubulis deal marks Gilead’s third major M&A transaction in 2026 alone. Earlier this year, the company acquired immunotherapy developer Arcellx for $7.8 billion in February, followed by a $2.2 billion transaction to purchase T-cell engager specialist Ouro Medicines in March. The pace of deal-making points to a company in active portfolio construction mode, systematically filling capability gaps across cell therapy, T-cell engagement, and now next-generation ADC technology.
Read further into Gilead’s Arcellx aquisition on OncoDaily.
Tubulis itself had attracted considerable external validation prior to the acquisition. The company raised $361 million in Series C funding in October 2025, and Bristol Myers Squibb demonstrated comparable confidence in the German biotech’s technology by entering a licensing agreement in 2023, committing $23 million upfront and pledging more than $1 billion in milestone payments.
What It Means for the ADC Landscape
The deal reinforces ADCs as the most intensely competed space in oncology drug development. With Daiichi Sankyo, AstraZeneca, Pfizer, and now Gilead all investing heavily in next-generation conjugation and payload technologies, the arms race for differentiated ADC platforms has reached a fever pitch. Tubulis’s linker and payload capabilities, designed to more selectively target tumor cells while minimizing off-target toxicity, sit at the frontier of where the field is heading.
For Gilead, the acquisition closes a meaningful gap. While Trodelvy remains a commercial anchor, its TOPO1i mechanism is increasingly crowded. Adding Tubulis brings next-generation platform depth, not just an asset, but the engine to build a sustained ADC pipeline capable of reaching tumors that current conjugate technologies miss.
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Written by: Semiramida Nina Markosyan, Editor, OncoDaily Canada