AbbVie Expands T-Cell Engager Portfolio with $2.1B Xilio Therapeutics Deal

AbbVie has once again demonstrated its commitment to expanding its oncology pipeline, signing a multi-program collaboration agreement with Xilio Therapeutics. The deal, announced on February 12, 2025, focuses on developing novel antibody-based immunotherapies, including masked T-cell engagers, using Xilio's proprietary tumor-activation technology.

Deal Structure and Financial Terms

Under the terms of the agreement, AbbVie will pay Xilio Therapeutics an upfront fee of $52 million, which includes a $10 million equity investment in the Waltham, Massachusetts-based biotech. The collaboration has the potential to reach up to $2.1 billion in option-related fees and milestones, with additional royalties possible on future sales.

This latest move follows AbbVie's recent trend of investing in T-cell engager technology. In January 2025, the company entered into a $1.05 billion deal with China's Simcere Zaiming for a phase 1-stage trispecific antibody. Previously, in October 2024, AbbVie paid $65 million upfront to license EvolveImmune's multispecific biologics for various oncology targets.

T-Cell Engager Technology and Industry Momentum

T-cell engagers, a type of bispecific antibody, have gained significant traction in the pharmaceutical industry. These molecules bind to T cells and a specific molecule on target cells, effectively directing T cells to attack cancer cells. The modality has been at the center of several recent biotech announcements, including Candid Therapeutics' $925 million biobucks agreement with WuXi Biologics and the launch of GSK-backed Ouro Medicines.

Xilio Therapeutics has been developing a pipeline of tumor-activated biologics, including masked multispecific molecules designed for tumor-selective activation. Concurrent with the AbbVie deal announcement, Xilio unveiled three preclinical T-cell engager programs targeting tumor-associated antigens PSMA, CLDN18.2, and STEAP1.

Strategic Implications for AbbVie's Oncology Portfolio

Dr. Theodora Ross, Vice President of Early Oncology R&D at AbbVie, emphasized the company's commitment to expanding its oncology efforts, stating, "This includes investigation of novel immunotherapy approaches that aim to generate improved next-generation cancer treatments for patients in need. This partnership with the Xilio team further exemplifies our commitment."

The collaboration with Xilio adds to AbbVie's growing portfolio of T-cell engager assets and partnerships, positioning the company as a significant player in this rapidly evolving field of cancer immunotherapy. As the pharmaceutical industry continues to invest heavily in T-cell engager technology, AbbVie's strategic moves suggest a long-term commitment to developing innovative oncology treatments.