In their study, the team engineered IgE versions of existing IgG therapies and tested them on mice with HER2-positive cancer cells
A team of scientists is exploring a promising new antibody that could offer hope for patients with treatment-resistant breast and ovarian cancers. This new antibody stimulates the immune system to target cancer cells more effectively, potentially slowing tumor growth in cases where conventional therapies have failed.
Immunotherapy, which harnesses the body’s immune system to fight cancer, has become an increasingly popular alternative to traditional treatments such as chemotherapy and radiotherapy. Among the most widely used immunotherapies are IgG antibodies, which activate the immune system to target cancer cells. However, this approach is not always effective, especially in patients with HER2-positive breast and ovarian cancers, where resistance to treatment can develop.
Researchers from King’s College London, UK, have now turned their attention to a different type of antibody, IgE, to tackle this challenge. Unlike IgG antibodies, IgE antibodies work by stimulating the immune system in a different way. They activate immune cells within the ‘microenvironment’ surrounding tumors, which is critical for directing the immune system to attack the cancer cells.
In their study, the team engineered IgE versions of existing IgG therapies and tested them on mice with HER2-positive cancer cells. The results were promising: IgE antibodies successfully directed immune cells to target and attack HER2-expressing cancer cells. Moreover, they were able to slow tumor growth in mice that had developed resistance to conventional treatments, offering new hope for patients who do not respond to current therapies.
Dr. Heather Bax, a researcher at King’s College London, explained that the tumors used in their study were known to be resistant to traditional treatments, underscoring the potential of IgE-based therapies for those whose cancer is no longer responsive to existing options.
One of the key findings of the study was the ability of IgE antibodies to reprogram the tumor’s immune microenvironment. Tumors often create an immunosuppressive environment that prevents the immune system from effectively attacking cancer cells. IgE antibodies were shown to shift this environment from being immunosuppressive to immunostimulatory, which enhances the body’s ability to mount a stronger immune response against the cancer.
The study, which was published in the Journal for ImmunoTherapy of Cancer (JITC), provides significant insight into how IgE antibodies could be used to fight HER2-positive cancers. Approximately 20% of breast and ovarian cancers express HER2, a protein that is linked to aggressive tumor growth. By generating IgE antibodies that target HER2, the researchers believe they have identified a novel way to reprogram the immune system to more effectively target these cancers.
“We demonstrate for the first time that IgE antibodies harness unique mechanisms to reprogram the immune microenvironment, enabling immune cells to effectively target HER2-expressing cancers, including those resistant to existing therapies,” said Dr. Bax, a Postdoctoral Research Fellow at St. John’s Institute of Dermatology, King’s College London.
