A 69-year-old patient named Susan Young had run out options. She was suffering from triple-negative breast. Different chemocherapies failed to prevent cancer cells to spread to her bones and skin. So she came to City of Hope National Medical Center to seek for help, where she was given a combination of the P53 cancer vaccine and an antibody drug. After six weeks of the treatment, her symptoms were greatly improved. The researchers at the research center described this effect as a miracle.
p53 is a tumor suppressor gene that normally functions to prevent cancer formation. This gene is frequently mutated in cancer, which may lead to the production of a mutant version of p53 protein that contributes to carcinogenesis. City of Hope researchers had developed a vaccine, called p53MVA, to enhance the immune response to mutant p53 proteins. When tested in patients with advanced gastrointestinal cancers, p53MVA proved to be safe. But the vaccine failed to work well in patients who had large amounts of PD1 protein in the T-cells. Later, the researchers found that a PD1 inhibitor -- which is similar to an existing antibody drug pembrolizumab -- could reactivate these patients' immune cells.
Then the researchers tested the combination of p53MVA and pembrolizumab in patients with different cancers. For current study, Young was given the combination and responded great to it. Six weeks after the therapy, her disease was greatly improved. “Internally in the lung area, the lesions are starting to fade,” said Dr. Yuan Yuan, a breast cancer oncologist at City of Hope. Besides, Young's skin cleaned up; her appetite became better; her psychological wellbeing was improved.
Although it is too early to say it is a cure, the breast team is exited about the success, according to Dr Don Diamond, chair of the Department of Experimental Therapeutics at City of Hope. In future research, the team hopes to test the combination in a full clinical trial.
CusAb offers p53 protein and HRP conjugated antibody.