
The open-label, dose-escalation trial aims to evaluate the pharmacokinetics, pharmacodynamics, safety, and initial efficacy of MT-303 in adults with advanced or metastatic HCC that overexpresses glypican-3 (GPC3). A key goal of the trial is to establish the recommended Phase II dose (RP2D) for MT-303.
Dr. Matthew Maurer, Chief Medical Officer of Myeloid, expressed excitement about the advancement, stating, “We are thrilled to have swiftly advanced MT-303 into the clinic as the first in vivo CAR therapy applicable to the majority of liver cancers, and other cancers expressing GPC3. MT-303 can be administered like any other off-the-shelf intravenous therapy, without the need for pretreatment conditioning, and offers the potential to trigger a coordinated immune response against the cancer, reinforced and maintained with ongoing repeat dosing.”
GPC3 is highly expressed in most HCC tumors with minimal expression in normal tissues, making it a significant target for cancer therapy. In preclinical models, MT-303 has demonstrated effectiveness as a monotherapy, showing its ability to combat tumors even in the absence of T cells. The therapy has shown strong expression in myeloid cells and a favorable safety profile in both rodents and non-human primates.
MT-303, a GPC3-FcA-LNP therapy, is designed to arm myeloid cells with a proprietary chimeric antigen receptor, enabling them to kill hepatocellular carcinoma cells and engage an adaptive immune response. This coordinated immune response is crucial for sustained immune surveillance and defense against tumor recurrence.
Dr. Timothy Humphries, lead principal investigator at Linear Clinical Research, highlighted the significance of this trial, stating, “Hepatocellular carcinoma is a highly lethal cancer with limited effective therapies. I am elated to bring the option and potential of MT-303, the first in vivo CAR therapy for this disease, to my patients with the hope of providing tolerable and durable clinical benefit.”
Daniel Getts, Ph.D., CEO of Myeloid, emphasized the company’s commitment to revolutionizing cancer treatment, saying, “The Myeloid team continues to push forward and revolutionize cancer treatment with the world’s first clinical-stage in vivo mRNA CAR therapies. With multiple clinical trials ongoing, including MT-302 for TROP2-targeting mRNA CAR, we are excited by the transformative potential of our in vivo immune cell programming for liver cancer patients.”
Myeloid’s platform integrates validated antibody/antigen binding with novel combinations of myeloid signaling domains encoded within a simple mRNA, delivered repeatedly using lipid nanoparticles (LNPs). This approach aims to provide personalized therapy benefits while reducing time and costs associated with ex vivo handling of patient cells and complex neoantigen sequencing.
About Liver Cancer
Liver cancer is the third leading cause of cancer death worldwide, with over 850,000 new cases diagnosed annually. Despite initial treatment successes with small molecule therapies, new treatment approaches have been limited, leaving patients with refractory liver cancer few options. Myeloid Therapeutics aims to address this substantial unmet need with MT-303, providing a coordinated and durable immune response to combat advanced disease.
About MT-303
MT-303 is a first-in-class, GPC3-FcA-LNP therapy with a robust preclinical profile supporting its progression into human trials. It represents Myeloid’s second in vivo CAR clinical program, highlighting their innovative approach to cancer treatment through immune cell programming.
About Myeloid Therapeutics
Myeloid Therapeutics is a clinical-stage immunology company engineering cutting-edge RNA technology to program immune cells to combat cancer and other deadly diseases. Headquartered in Cambridge, MA, Myeloid is committed to advancing RNA therapeutics to conquer cancer and transform patient care.

Check out our mRNA service to expedite your vaccine research
PackGene Biotech is a world-leading CRO and CDMO, excelling in AAV vectors, mRNA, plasmid DNA, and lentiviral vector solutions. Our comprehensive offerings span from vector design and construction to AAV, lentivirus, and mRNA services. With a sharp focus on early-stage drug discovery, preclinical development, and cell and gene therapy trials, we deliver cost-effective, dependable, and scalable production solutions. Leveraging our groundbreaking π-alpha 293 AAV high-yield platform, we amplify AAV production by up to 10-fold, yielding up to 1e+17vg per batch to meet diverse commercial and clinical project needs. Moreover, our tailored mRNA and LNP products and services cater to every stage of drug and vaccine development, from research to GMP production, providing a seamless, end-to-end solution.
Related News
Navega Therapeutics Receives $4 Million CIRM Grant to Advance Epigenetic Gene Therapy for Chronic Pain
SAN DIEGO, CA – February 4, 2025 – Navega Therapeutics, a pioneering biotechnology company developing cutting-edge epigenetic gene therapies, today announced a significant milestone with the receipt of a $4 million Translational Science grant from the California...
Akribion Therapeutics Secures €8 Million in Seed Financing to Advance Novel RNA-Guided Cell Depletion Technology
ZWINGENBERG, Germany, February 4, 2025 – Akribion Therapeutics, a biotechnology company pioneering a unique, RNA-guided, nuclease-based technology for programmable cell depletion, today announced the closing of an €8 million Seed financing round. The round was led by...
UF-Kure19 CAR-T Cell Therapy Demonstrates High CR Rates, Low Toxicity in R/R NHL
Treatment with UF-Kure19, a rapidly manufactured CAR T-cell therapy, led to complete responses (CR) and low toxicity in patients with relapsed/refractory non-Hodgkin lymphoma, according to data from a single-arm, mult-center phase 1 study (NCT05400109) presented at...
Opinion: Companies Vie to Develop a Hunter Syndrome Therapy That Reaches the Brain
Several companies—including JCR Pharmaceuticals, Denali Therapeutics and Regenxbio—have products in the pipeline that could improve treatment options for this rare disease. Hunter syndrome is a rare, X‐linked disease caused by a deficiency of the lysosomal enzyme...
Related Services

Plasmids GMP Services

AAV GMP Services
