Precision Medicine Opens New Possibilities to Treat Rheumatoid Arthritis

Genetic sequencing of joint biopsies may identify which patients with rheumatoid arthritis may respond to therapy.

Research into individualized treatments have been progressing across nearly all diseases, with a majority aimed at cancer. For the first time, researchers have taken a precision medicine approach to treating rheumatoid arthritis (RA).

This innovative approach to treating RA is based on genetic profiling of joint tissue to help choose the optimal therapy, according to a study published by Arthritis & Rheumatology.

If these findings translate to a clinical setting, patients may not have to waste time on ineffective treatments that increase the risk of disease progression, according to the researchers.

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"Now we can start to predict which drugs a patient will respond to," said co-senior author Harris Perlman, PhD. "We can truly do precision medicine for rheumatoid arthritis. I believe this could be game changing."

The current approach to RA treatment is largely trial and error, with many patients failing to respond to therapy, according to the study authors. Not only can this exacerbate RA, but it also accounts for a significant portion of medical spending waste.

"We have so many different biologic drugs and there's no rhyme or reason to give one drug versus the other," Dr Perlman said. "We waste $2.5 billion a year in ineffective therapy. And patients go through 12 weeks of therapy, don't respond and get upset."

This study was the first in the United States to use ultrasound technology to guide a tissue biopsy of the affected joint, according to the authors. The traditional approach is to determine the efficacy of a therapy and disease progression by analyzing a blood sample.

"It's just like oncology, where you go to the tumor. Why go anywhere else? In rheumatoid arthritis, we've never gone to the target organ,” Dr Perlman said.

The authors examined tissue from 41 patients with RA, focusing on macrophages. These immune cells are overactive in RA and produce inflammatory proteins that obliterate the joints. Biologic drugs indicated for RA target these proteins to reduce disease progression.

The researchers grouped patients based on the genes produced by their macrophages and identified 2 groups that shared parts of their genetic profiles, according to the study. Next, they identified patients whose joints were improving and which biologics they were taking.

Additionally, a gene sequence linked to early disease was discovered. This may help patients start treatment earlier and experience a better outcome, according to the study.

Further studies will aim to predict which patients will achieve the best response to biologic therapies based on genetics, the authors said.

"The idea is to develop gene sequences to predict whether a patient will respond or not," Dr Perlman said. "Our goal is that this procedure will become the standard of care of for all patients with rheumatoid arthritis."