Gilead Sciences Completes Acquisition of Tubulis Further Strengthening Oncology Portfolio

Key Terms

antibody-drug conjugate medical

An antibody-drug conjugate is a targeted medicine that combines an antibody, which can identify specific cells, with a powerful drug designed to destroy those cells. This approach allows for precise treatment, minimizing damage to healthy tissue. For investors, developments in this area can signal advances in cancer therapies and potential growth opportunities in the biotech sector.

adc medical

An antibody-drug conjugate (ADC) is a targeted cancer medicine that pairs an antibody that recognizes specific markers on tumor cells with a potent cell-killing drug, connected so the toxic payload is delivered directly to the cancer. For investors, ADCs matter because successful ADCs can improve patient outcomes and reduce side effects compared with traditional chemotherapy, shaping clinical trial success, regulatory approval chances, commercial demand, and a company’s valuation much like a guided missile versus a general bomb.

topoisomerase-i inhibitor medical

A topoisomerase-I inhibitor is a drug that blocks the enzyme topoisomerase I, which helps cells untwist and copy their DNA; by stopping that process the drug causes breaks in DNA and tends to kill rapidly dividing cells such as cancer cells. Investors care because these compounds are often cancer therapies whose clinical trial results, safety profile, regulatory approvals, and market potential can materially affect a company's revenue prospects and risk profile—like a new product that can open or close a company's growth path.

phase i/iia medical

An early-stage clinical trial program that combines Phase I (primarily testing safety and finding a tolerable dose) with Phase IIa (initial checks for whether the drug shows signs of working in patients). Think of it as trying a new product with a small group to confirm it’s safe and gives early benefits before a larger rollout. For investors, these studies are major risk/reward checkpoints: positive results can boost value, while failures are common and costly.

non-small cell lung cancer medical

A broad category of lung tumors that grow from the cells lining the airways and make up the majority of lung cancer cases; it includes several subtypes that behave and respond to treatment differently, like different models of the same car family. It matters to investors because its large patient population and variety of treatment options — surgery, traditional chemo, targeted drugs and immunotherapies — create major markets where clinical trial results, drug approvals or changing treatment guidelines can quickly affect a company’s revenue and stock value.

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– Acquisition Builds on Gilead’s Leadership in Oncology with Potentially Best-in-Class Antibody-Drug Conjugate and Next Generation Platform –

FOSTER CITY, Calif.--(BUSINESS WIRE)-- Gilead Sciences, Inc. (Nasdaq: GILD) today announced the successful completion of its previously announced acquisition of Tubulis GmbH, a private Germany-based, clinical-stage biotechnology company developing next-generation antibody-drug conjugates (ADCs).

The acquisition brings Gilead next-generation ADC assets and a platform designed to maximize patient benefit through more selective delivery of diverse payloads to tumors. Tubulis’ technologies enable the development of unique ADCs with superior biophysical properties, capable of achieving robust on-tumor payload exposure that can translate to long-lasting anti-tumor activity. The addition of Tubulis’ lead asset, TUB-040, a NaPi2b-directed topoisomerase-I inhibitor (TOPO1i) ADC, which has demonstrated promising activity in platinum-resistant ovarian cancer, and TUB-030, a 5T4-directed ADC that is being investigated across various solid tumor types, complements Gilead’s existing ADC portfolio.

“We look forward to welcoming the Tubulis team to Gilead and building on the significant progress they have made in advancing novel ADC technology for people living with cancer,” said Daniel O’Day, Chairman and Chief Executive Officer, Gilead Sciences. “Our two-year collaboration with Tubulis gave us strong conviction in their team, their programs and their technologies. We will now combine our strengths in service of providing new options for some of the most challenging forms of disease.”

Under the terms of the agreement, Gilead acquired all the outstanding equity of Tubulis for $3.15 billion in upfront considerations on a cash-free, debt-free basis, and up to $1.85 billion in contingent milestone payments. The Tubulis team will continue to be based in Munich, Germany, establishing The Tubulis ADC Innovation Center. This new Center will be a hub for the team to continue building on its integrated discovery, manufacturing and clinical capabilities to advance next generation ADCs.

About TUB-040 and the Tubutecan Technology

TUB-040 is an investigational antibody-drug conjugate (ADC) that targets NaPi2b, a protein expressed at high levels in several tumor types, including ovarian, lung, and endometrial cancer. TUB-040 utilizes the Tubutecan technology engineered to have eight chemotherapy payloads (topoisomerase-I inhibitor) attached to a stable, cleavable linker system that allows for potent tumor cell killing. This design allows TUB-040 to deliver the drug directly to cancer cells while limiting exposure to healthy tissue, improving the tolerability of the ADC compared to earlier ADC technologies. In early clinical studies, TUB-040 has shown encouraging anti-tumor activity with a manageable safety profile in patients with platinum-resistant ovarian cancer, as reported at ESMO 2025. It is currently being evaluated in an ongoing multicenter Phase I/IIa study in patients with platinum-resistant ovarian cancer and relapsed or refractory non-small cell lung cancer.

About Gilead and Kite Oncology

Gilead and Kite Oncology are working to transform how cancer is treated. We are innovating with next-generation therapies, combinations and technologies to deliver improved outcomes for people with cancer. We are purposefully building our oncology portfolio and pipeline to address the greatest gaps in care. From antibody-drug conjugate technologies and small molecules to cell therapy-based approaches, we are creating new possibilities for people with cancer.

About Gilead Sciences

Gilead Sciences, Inc. is a biopharmaceutical company that has pursued and achieved breakthroughs in medicine for more than three decades, with the goal of creating a healthier world for all people. The company is committed to advancing innovative medicines to prevent and treat life-threatening diseases, including HIV, viral hepatitis, COVID-19, cancer and inflammation. In 2025, Gilead announced a planned $32 billion investment to further strengthen its U.S. footprint to power the next era of discovery, job creation and public health preparedness – while continuing to invest globally to ensure patients everywhere benefit from its scientific innovation. Gilead operates in more than 35 countries worldwide, with headquarters in Foster City, Calif.

Forward-Looking Statements

This press release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 that are subject to risks, uncertainties and other factors. All statements other than statements of historical fact are statements that could be deemed forward-looking statements, including all statements regarding the intent, belief or current expectation of Gilead and Tubulis and members of their respective senior management teams. In some cases, forward-looking statements can be identified by the use of words such as “anticipate,” “believe,” “estimate,” “expect,” “intend,” “seek,” “may,” “plan,” “project,” “should,” “target,” “will,” or the negative of these terms or other similar expressions, although not all forward-looking statements contain these words. Forward-looking statements include, without limitation, statements regarding the transaction and related matters, prospective performance and opportunities, post-closing operations and the outlook for the companies’ businesses; the potential of Tubulis’s ADC programs and platform; The Tubulis ADC Innovation Center; and any assumptions underlying any of the foregoing. Actual results may differ materially from those currently anticipated due to a number of risks and uncertainties. Risks and uncertainties that could cause the actual results to differ from expectations contemplated by forward-looking statements include: the effects of the transaction on relationships with employees, other business partners or governmental entities; the difficulty of predicting the timing or outcome of regulatory approvals or actions, if any; the risk that, if the transaction is consummated, the businesses will not be integrated successfully and that other anticipated benefits from the transaction will not be realized; the impact of competitive products and pricing; other business effects, including the effects of industry, economic or political conditions outside of the companies’ control; transaction costs; actual or contingent liabilities; the risk that Gilead may not realize the expected benefits of this acquisition transaction; the ability of Gilead to advance their product pipeline and successfully commercialize product candidates following the acquisition; the ability of the parties to initiate and complete clinical trials involving such product candidates in the currently anticipated timelines or at all; the possibility of unfavorable results from one or more of such trials involving such product candidates; uncertainties relating to regulatory applications and related filing and approval timelines, including potential applications for programs and/or indications currently under evaluation, and the risk that any regulatory approvals, if granted, may be subject to significant limitations on use or subject to withdrawal or other adverse actions by the applicable regulatory authority; and any assumptions underlying any of the foregoing. These and other risks, uncertainties and factors are described in detail in Gilead’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2026, as filed with the U.S. Securities and Exchange Commission. The reader is cautioned that any such forward-looking statements are not guarantees of future performance and involve risks and uncertainties and is cautioned not to place undue reliance on these forward-looking statements. All forward-looking statements are based on information currently available to Gilead, and Gilead assumes no obligation and disclaims any intent to update any such forward-looking statements.

Gilead and the Gilead logo are trademarks of Gilead Sciences, Inc., or its related companies.

For more information about Gilead, please visit the company’s website at www.gilead.com, follow Gilead on X/Twitter (@Gilead Sciences) and LinkedIn (@Gilead-Sciences).

View source version on businesswire.com: https://www.businesswire.com/news/home/20260520959712/en/

Priscilla White, Media
public_affairs@gilead.com

Jacquie Ross, Investors
investor_relations@gilead.com

Source: Gilead Sciences, Inc.