Gilead strikes again, penning $5bn deal to buy Tubulis

Gilead Sciences has signed its third acquisition deal since the start of the year, agreeing to buy Germany's Tubulis and its pipeline of antibody-drug conjugates (ADCs) for cancer.

Assuming the transaction goes through, Gilead will pay $3.15 billion in cash to buy all of the Munich-based biotech's outstanding equity, with another $1.85 billion on offer if Tubulis' ADC candidates achieve certain objectives.

The deal adds to a steady stream of biopharma takeovers of late, with 2026 shaping up to be a landmark year for sector M&A if the trend continues.

In its statement on the deal, Gilead highlighted TUB-040, a NaPi2b-targeting ADC currently in phase 1b/2 development for platinum-resistant ovarian cancer (PROC) and non-small cell lung cancer, and 5T4-directed TUB-030, which has initial clinical data in various solid tumours.

Gilead is still trying to close two other acquisitions announced in the last few weeks, namely a $7.8 billion play for its cancer cell therapy partner Arcellx and a $2.2 billion offer for autoimmune disease therapy developer Ouro Medicines. It has been collaborating with Tubulis for a couple of years, so it has seen the biotech's ADC platform at close quarters.

The Tubulis deal comes a few months after the German company raised an impressive 308 million ($358 million) in a Series C, led by Venrock Healthcare Capital Partners, that was earmarked for the clinical development of TUB-040 and TUB-030.

Tubulis has been built on a suite of technologies designed to make ADCs more stable, reducing the toxicity that can occur if, for example, the payload drug is released from the molecule before it reaches the site of a tumour. If the takeover completes, Tubulis will operate as a dedicated ADC research organisation within Gilead.

Gilead's chief executive, Daniel O'Day, said the acquisition is "a significant milestone in Gilead's progress in oncology," part of an expansion by the company into new therapeutic areas and modalities as it prepares for the expiration of patents on some of its top-selling HIV therapies in the coming years.

It has a heritage in ADCs with drugs like TROP2-targeting Trodelvy (sacituzumab govitecan) for breast cancer, which was the crown jewel in its $21 billion acquisition of Immunomedics in 2020 and saw sales reach $1.4 billion last year, but is slowing down in the face of competition in the market and the withdrawal of an FDA approval for bladder cancer.

O'Day said the alliance with Tubulis "has given us strong conviction in their programmes and research capabilities."

Tubulis is one of several biopharma companies that have looked at the development of Napi2b-directed drugs, although the class has seen some major clinical setbacks.

ADC Therapeutics' upifitamab rilsodotin, for instance, failed to hit its objectives in the phase 1/2 UPLIFT trial in PROC, while other developers, including Roche, Mersana Therapeutics, and ZymeWorks, have either abandoned or deprioritised their work in this category.

Aside from Tubulis, other biotechs with active Napi2b programmes – all in early development – include MediLink Therapeutics, Adcentrx, Merck KGaA, and LaNova.