Vir Biotechnology, entered a collaboration and license agreement with Gilead to discover and engineer three novel PRO-XTEN dual-masked T-cell engager development candidates targeting selected solid tumor-associated antigens.

As part of the collaboration, Gilead will hold an exclusive license to develop and commercialize the resulting therapies, with Vir eligible to receive up to $1.87 billion in combined near-term and milestone payments.¹

Vir will be responsible for discovery, design and optimization of the three T-cell engager candidates, applying its proprietary Daisy platform for rapid, multiparameter optimization alongside its universal PRO-XTEN masking technology.¹ Gilead is granted an exclusive license to nominate and advance candidates generated through the collaboration and is expected to take on subsequent development, manufacturing and commercialization activities.

What are the details of the deal?

Vir Biotechnology is eligible to receive up to $135 million in total upfront and near-term preclinical milestone payments, which breaks down into $90 million in upfront consideration, consisting of $65 million in cash and a $25 million equity investment priced at a 30% premium, plus up to $45 million in potential near-term preclinical milestones.¹ Beyond that initial tranche, Vir has the potential to receive up to $1.74 billion in further development, regulatory and commercial milestone payments, along with tiered royalties on net sales ranging from high single digits to low double digits.¹

How does the masking technology work?

T-cell engagers are designed to direct the immune system, particularly T-cells, to destroy cancer cells. While the modality has become an important treatment option in blood cancers, its use in solid tumors has historically been limited by toxicity. Vir’s PRO-XTEN masking technology is built to address that limitation. It is designed to extend the half-life of the molecule and keep T-cell engagers inactive, or masked, until they reach the tumor microenvironment.² There, tumor-specific proteases cleave off the mask and activate the T-cell engager, triggering T-cell killing of cancer cells. By extending half-life and confining activity to the tumor microenvironment, the company says the technology could limit toxicity, widen the therapeutic index of T-cell engagers, and potentially enable less frequent dosing regimens.²

Putnam’s CEO Matt Riordan spoke with Pharmaceutical Executive about the importance of innovation, specifically highlighting how it’s playing out in the oncology space. “Solid tumors represent the vast majority of cancer cases worldwide, and if CAR-T therapies can be successfully translated, they could redefine the standard of care for millions of patients.”

Why does this partnership matter for both companies?

For Vir, the agreement adds external validation to its discovery engine while preserving the company’s own clinical oncology ambitions. “We believe T-cell engagers have a powerful role to play in the future of immunotherapy to treat cancer,” said Marianne De Backer, president and chief executive officer of Vir Biotechnology. “This collaboration with Gilead provides an opportunity to generate multiple differentiated candidates aimed at difficult-to-address solid tumors and to expand the potential impact of our science, while also advancing our own clinical oncology portfolio. This transaction provides further external validation of Vir Biotechnology’s integrated discovery capabilities and the broad potential of the PRO-XTEN platform.”

For Gilead, the collaboration extends an oncology pipeline that already includes substantial development infrastructure. “We look forward to combining Gilead’s established and growing oncology capabilities, including our extensive development expertise and focus on next-generation immunotherapies, with Vir Biotechnology’s innovative discovery capabilities,” said Flavius Martin, executive vice president, research, Gilead Sciences. “Together with Vir Biotechnology, we seek to bring meaningful innovative therapeutics to patients.”

Sources

1. Vir Biotechnology Enters Multi-Program Collaboration and License Agreement with Gilead Sciences to Discover and Develop Novel PRO-XTEN^® Dual-masked T-cell Engagers for Solid Tumors Vir Biotechnology October 14, 2026,https://www.businesswire.com/news/home/20261014783426/en/Vir-Biotechnology-Enters-Multi-Program-Collaboration-and-License-Agreement-with-Gilead-Sciences-to-Discover-and-Develop-Novel-PRO-XTEN-Dual-masked-T-cell-Engagers-for-Solid-Tumors
2. PRO-XTEN protease-releasable masking platform Vir Biotechnology Date Accessed, October 14, 2026, https://www.vir.bio/science/PRO-XTEN-platform/