Patient Survives Metastatic Breast Cancer Thanks to New Immunotherapy Treatment

T-lymphocyte. (Credit: NIH)

A patient with metastatic breast cancer has made a dramatic recovery after receiving a personalised therapy using her own cells. 

This is the first time this type of therapy has worked in breast cancer, which suggests that it may be able to help many more with common types of cancer, even after they’ve spread to other parts of the body. The findings are published in Nature Medicine.

The woman who received the new therapy had advanced breast cancer that had spread to other organs, despite receiving multiple treatments, including several chemotherapy and hormonal treatments. 

“She had tennis ball-sized lesions throughout her liver”, NIH’s Steven Rosenberg said. “It probably would have killed her in the next two or three months.” 

But Dr. Rosenberg and his colleagues at the National Insitute of Health, Maryland, tried a new method.

To treat her, the researchers sequenced DNA and RNA from one of her tumours, as well as normal tissue to see which mutations were unique to her cancer, and identified 62 different mutations in her tumour cells.

 

“It is ironic that the very mutations that cause the cancer may prove to be the best targets to treat the cancer.”

 

The researchers then tested different TILs from the patient to find those that recognised one or more of these mutated proteins. TILs recognized four of the mutant proteins, and the TILs then were expanded and infused back into the patient. She was also given the checkpoint inhibitor pembrolizumab to prevent the possible inactivation of the infused T-cells by factors in the tumour microenvironment.

 

Left: MRI scans of a woman with breast cancer before TIL therapy show a lesion invading the chest wall (top) and metastatic lesions in the liver (bottom). Right: Scans 14 months after treatment show all lesions have disappeared. (Credit: NCI)

Six weeks after treatment, the woman’s tumours had halved in size, and a year later, they had disappeared, and not returned more than 22 months later.

 

Gene Test Shows About 70% of Breast Cancer Patients Can Skip Chemo

 

The approach is a modified form of adoptive cell transfer (ACT) and has shown to be effective previously in treating melanoma, which has high levels of somatic, or acquired mutations. However, it has been less effective with some common epithelial cancers, or cancers that start in the lining of organs, that have lower levels of mutations, such as breast cancers. 

“This research is experimental right now,” Dr. Rosenberg said. “But because this new approach to immunotherapy is dependent on mutations, not on cancer type, it is in a sense a blueprint we can use for the treatment of many types of cancer.” 

“This is an illustrative case report that highlights, once again, the power of immunotherapy,” commented Dr. Tom Misteli, Director of CCR and NCI. “If confirmed in a larger study, it promises to further extend the reach of this T-cell therapy to a broader spectrum of cancers.” 

 

Precision Medicine Is Working

 

Investigators have seen similar results using mutation-targeted TIL treatments for patients in the same trial with other epithelial cancers. Dr. Rosenberg explained that results like this in patients with solid epithelial tumours are important because ACT has not been as successful with these kinds of cancer as with other types that have more mutations.

The “big picture” here, Dr. Rosenberg said, is that this kind of treatment is not cancer-type specific. 

“All cancers have mutations, and that’s what we’re attacking with this immunotherapy,” he said. “It is ironic that the very mutations that cause the cancer may prove to be the best targets to treat the cancer.”