Lyell Immunopharma, Inc., a late-stage clinical biotech company developing next-generation chimeric antigen receptor (CAR) T-cell therapies, has strengthened its solid tumor portfolio through the acquisition of global rights to LYL273 (formerly GCC19CART) from Innovative Cellular Therapeutics (ICT). The therapy targets guanylyl cyclase-C (GCC) and is being developed to treat metastatic colorectal cancer (mCRC) and other GCC-expressing tumors.
In a Phase 1 clinical trial conducted in the United States, patients with refractory mCRC treated with LYL273 achieved a 67% overall response rate and an 83% disease control rate (including complete and partial responses and stable disease), according to RECIST 1.1 criteria. The therapy also demonstrated a manageable safety profile at the highest tested dose.
LYL273 combines GCC-targeted CAR T technology with CD19 CAR expression and a controlled cytokine release mechanism, designed to improve T-cell expansion, immune infiltration, and tumor cell killing within the challenging solid tumor environment.
Dr. Benjamin L. Schlechter, Senior Physician at the Dana-Farber Cancer Institute and lead investigator in the trial, emphasized the significance of these results:
“We rarely see such deep and durable responses in colorectal cancer patients treated with multiple prior lines of chemotherapy. The outcomes in this cohort are very encouraging, and I look forward to working with Lyell to advance this therapy for patients with advanced colorectal cancer.”
Lyell co-founder and Board Chairman Dr. Richard Klausner, former Director of the National Cancer Institute, noted the breakthrough potential:
“The ability to treat solid tumors with an acceptable safety profile has been the holy grail for CAR T-cell therapy. These early results suggest we may finally be on the path to breaking the barrier for solid cancer.”
Colorectal cancer remains the second leading cause of cancer deaths worldwide, with around 53,000 expected deaths in the U.S. in 2025. Current therapies achieve response rates below 6% in advanced stages, underscoring the urgent need for new treatments. Since GCC is expressed in over 95% of colorectal cancers and limited in healthy tissues, it represents a promising target for selective, effective therapy.
With this acquisition, Lyell positions itself at the forefront of developing novel CAR T-cell therapies aimed at expanding immunotherapy’s reach into solid tumors, an area with significant unmet medical need.