TRexBio Announces Collaboration Partner Lilly Has Initiated a Phase 1 Study of TRB-051 for Autoimmune and Inflammatory Diseases

in Portfolio News

  • TRexBio has earned a double-digit million dollar milestone payment and is eligible to receive more than $1.1 billion on achievement of certain development, regulatory, and commercial milestones across partnered programs
  • TRB-051 program is the first to enter the clinic under the Research Collaboration and License Agreement between TRexBio and Lilly
  • Collaboration leveraged TRexBio’s Deep Biology Platform, which maps regulatory T cell (“Treg”) behavior in human tissue to identify and target immune-regulatory pathways for novel therapeutic development

SOUTH SAN FRANCISCO, June 26, 2024 – TRex Bio, Inc. (“TRexBio”), a biotechnology company decoding human tissue immune biology to create revolutionary therapeutics, today announced that collaboration partner Eli Lilly and Company (“Lilly”) has initiated a Phase 1 first-in-human study of TRB-051, a modulator of immune effector cells, for treatment of autoimmune and inflammatory diseases. The program is one of three under the research collaboration and exclusive worldwide license agreement between TRexBio and Lilly, which leverages TRexBio’s proprietary Deep Biology platform to identify and develop novel therapies for the treatment of immune-mediated diseases. Pursuant to the agreement, TRexBio has earned a double-digit million dollar milestone payment and is eligible to receive more than $1.1 billion on achievement of certain development, regulatory, and commercial milestones across partnered programs. TRexBio is also entitled to receive tiered royalties on product sales.

“We are excited by the potential of TRB-051 to bring durable clinical benefit to patients in need of new therapies to treat dysregulation of the immune system,” said Alison Budelsky, Ph.D., Vice President, Immunology Research of Lilly. “Our preclinical work together with TRexBio pointed us to a translational hypothesis we’re eager to test in the clinic with TRB-051.”

“Given Lilly’s status as a global industry leader, we view this milestone as further validation of the power of our Deep Biology Platform,” said Melanie Kleinschek, DVM, Ph.D., Chief Scientific Officer of TRexBio. “We focus on restoring homeostasis at the site of inflammation across a range of immune-mediated diseases, and our platform’s ability to map critical regulatory pathways in healthy and diseased tissues points the way in our drug discovery efforts. We’re seeing early signs of success for this approach in the progress of our Lilly-partnered programs and in our own pipeline of wholly-owned assets moving toward the clinic.”

TRexBio’s proprietary Deep Biology Platform was also integral in the identification and advancement of TRexBio’s wholly-owned lead program, TRB-061, an agonist targeting TNF receptor 2 (TNFR2) designed to augment Tregs at the site of inflammation. TRB-061 is currently in IND enabling studies, and the company anticipates advancing the program into the clinic in the first half of 2025.

About TRexBio

TRexBio is a biotechnology company leveraging cutting edge computational biology tools, a focus on human tissue, and expertise in immunobiology to develop revolutionary therapeutics for immune-mediated diseases. Our powerful Deep Biology platform maps human tissue Treg behavior to disease processes to identify and characterize novel targets for therapeutic intervention. Leveraging this platform, we are building a broad portfolio of novel therapies that modulate the immune system to restore human tissue immune homeostasis. TRexBio was founded and seed funded by SV Health Investors in 2018 and is headquartered in South San Francisco, California. TRexBio was one of the first companies in residence at Lilly Gateway Labs, a shared innovation space where Eli Lilly and Company enables and engages high-caliber, early-stage biotechs to do break-through science. For more info, visit


Company: Laura Berner, J.D., MBA, Chief Operating Officer, TRex Bio, Inc.,

Media: Jessica Yingling, Ph.D., Little Dog Communications Inc., +1-858-344-8091,

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