The trial will determine the recommended Phase II dose for MT-303.
Myeloid Therapeutics has dosed the first subject in a Phase I clinical trial of MT-303 for treating hepatocellular carcinoma (HCC).
The open-label, dose-escalation trial is designed to assess the pharmacokinetics, pharmacodynamics, safety and initial efficacy of MT-303 in adults with advanced or metastatic HCC that overexpresses GPC3.
This trial will also determine the recommended Phase II dose (RP2D) for MT-303.
An in vivo mRNA CAR programme of Myeloid, MT-303 is the second to enter clinical trials, advancing from their pipeline of in vivo immune cell programming therapies.
This candidate is a GPC3-FcA-LNP therapy and is claimed to have a robust preclinical profile that supported its progression into human trials.
GPC3 is highly expressed in most HCC tumours, with minimal expression in normal tissues, and its increased levels are associated with tumour growth.
In preclinical models of GPC3/HCC, MT-303 has shown effectiveness as a monotherapy, demonstrating its ability to combat tumours even without T cells.
The therapy also showed to express strongly in myeloid cells and had a favourable safety profile in rodents and non-human primates.
Compared with other treatments, MT-303 is said to have the potential to provoke a comprehensive immune response by presenting tumour neoantigens to activate T cells.
Myeloid chief medical officer Dr Matthew Maurer said: “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.”
