The company is conducting a Phase 1b trial of TG02 alone, and in combination with Merck’s Keytruda (pembrolizumab), as a treatment for colorectal cancer stemming from a Ras protein mutation. TG02 is a cancer vaccine designed to trigger an immune response to a tumor.
Targovax said the trial (NCT02933944) will cover the therapy’s safety and ability to work with granulocyte macrophage colony stimulating factor, or GM-CSF, to trigger an immune response. The roles the factor plays include being involved in the maturation of immune cells known as macrophages.
There will be two parts to the trial. In part one, researchers will look at TG02 as a stand-alone therapy. In part two, they will study it in combination with Keytruda, a checkpoint inhibitor, in patients with rectal cancer that has returned.
Targovax researchers are recruiting about 10 participants in Australia and New Zealand for each part of the trial. Patients will be able to participate in only one of the two parts.
Researchers conducted the safety review on the first three patients in the first stage of the trial. They found no safety concerns, and a review board cleared the trial to continue.
TG02 is a second-generation RAS neo-antigen vaccine. This means Targovax designed it to trigger an immune response against cells with Ras protein mutations.
The trial is the first time the vaccine has been administrated in humans.
TG01 targets the Ras mutation found in more than 85 percent of pancreatic cancers. The immunotherapy, which contains seven synthetic proteins, triggered immune responses against the cancer, studies showed.
Exploratory clinical trials showed TG02 can also trigger an immune response. Researchers found high levels of PD-1, a protein associated with a number of cancers, in immune T-cells circulating in blood and infiltrating tumors. This strengthened the argument for combining TG02 and a PD-1 checkpoint inhibitor such as Keytruda to fight cancer.
The trial’s primary objectives will be to assess TG02’s safety and ability to trigger an immune response.
“This is the first time TG02 has been administered to patients, and we are very pleased that there were no issues reported in this initial safety review,” Magnus Jäderberg, Targovax’s chief medical officer, said in a press release. “The early clinical [trial] data is also encouraging, indicating immune activation in vaccinated patients in a manner that is consistent with the drug’s postulated mechanism of action. We are now eager to initiate the combination trial with Keytruda, and we are hopeful that PD-1 blockade might boost the effect of TG02 vaccination.”