Cancer Immunotherapy Does Not Increase Lupus Patients’ Risk of Autoimmune Reactions, Study Finds

Lupus patients’ risk of an autoimmune reaction while receiving a cancer immunotherapy is no greater than the general population’s, a Mayo Clinic study reports.

The same is true of other rheumatic diseases, most of which affect joints and connective tissue, researchers said. Few people have flare-ups of these disorders when they go on immune checkpoint inhibitors, they said.

The research, “Cancer immunotherapy in patients with preexisting rheumatologic disease: the Mayo Clinic experience,” appeared in the journal Arthritis & Rheumatology.

Some immune cells have checkpoints that must be activated or inactivated to generate an immune response. Cancer cells use the checkpoints to avoid an immune system attack.

Scientists have developed medicines known as immune checkpoint inhibitors to prevent cancer cells from activating the checkpoints. They allow immune cells to recognize the threat that cancer poses, and attack it.

Examples of checkpoint molecules that the cancer medications target are the proteins PD-1 and CTLA-4. Both are found in immune T-cells. When activated, they hamper the T-cells’ functioning.

fScientists know immune checkpoint inhibitors can cause immune-related side effects. One thing they haven’t known is how often the side effects surface in patients with different rheumatic diseases.

A Mayo Clinic team decided to check the records of all rheumatic-disease patients who received checkpoint inhibitors at their treatment facility between 2011 and 2016.

The study included 16 rheumatic disease patients who ended up developing cancer. Two had lupus. Ten of the 16 developed melanoma, and six other cancers. Patients’ median age was 68 1/2.

“To our knowledge, this represents the largest single-center cohort of patients with rheumatologic diseases who were exposed to modern cancer immunotherapy,” the researchers wrote.

The immune checkpoint inhibitors that the patients received included Opdivo (nivolumab), Keytruda (pembrolizumab), and Yervoy (ipilimumab). They were given mostly to patients who had failed to respond to other types of cancer therapy. Seven who received checkpoint inhibitors were also on  immunosuppressive therapies or glucocorticoids for their rheumatic disease.

Only six patients experienced flare-ups of their rheumatic disease or other side effects from the inhibitors. Doctors stopped the flare-ups by giving the patients corticosteroids or discontinuing the inhibitors.

Researchers said the results indicated that modern, potentially life-saving cancer treatments are safe in some patients with a rheumatic disease.

“Based on our observations, immune checkpoint inhibitor therapy should be considered in select patients with pre-existing rheumatologic disease,” Dr. Uma Thanarajasingam, the study’s senior author, said in a press release.

The team called for multi-center clinical trials to shed light on the risk of flare-ups and immune-related side effects in patients with different kinds of rheumatic diseases.

These studies would help scientists “better understand their safety profile in this under-studied patient group, as well as elucidate risk factors and biomarkers for the development of immune-related adverse effects,” they wrote.