Can a Blood-Based Test Predict TNFi Nonresponse in RA?
A blood test that uses a patient’s unique genetic signature has shown some ability to predict nonresponse to tumor necrosis factor inhibitors as treatment for rheumatoid arthritis, an observational clinical study has found, but the test’s predictive accuracy was well below 100%.
The test is the blood-based molecular signature response classifier (MSRC) that uses RNA sequencing data based on 23 different biomarkers: 19 RNA transcripts and 4 clinical features. The clinical features are body mass index, gender, patient global assessment, and anticyclic citrullinated protein (anti-CCP) status.
The NETWORK-004 study, published in Rheumatology and Therapy, was able to stratify patients who were likely to respond inadequately to TNFi therapy and could provide patient-specific information to guide therapy choice in RA patients regardless of whether they’ve already been on TNFi therapy. The study evaluated the MSRC test in 504 patients, 391 of whom were treatment naive.
Avoiding “Fail First” Approach
The idea behind the test is to circumvent the “fail first” approach in finding the right therapy for RA in an individual patient. While the test costs $4,995, Alif Saleh, chief executive officer of Scipher Medicine, which markets the test under the name PrismRA, said in a press release that it has the potential to reduce costs by $19,000 or more per patient per year by avoiding treatments that don’t work. A previous study, which Scipher funded, reported that the test resulted in savings of $7,379 in per-patient costs of ineffective therapy. The same study reported a 25% decrease in costs for ineffective treatments for Medicare-eligible patients.
The price of RA drugs, particularly anti-TNF agents, is hefty and rising. GoodRx has reported that the price of RA drugs increased 92% from 2014 to 2019, and the prices for anti-TNF agents such as etanercept and adalimumab more than doubled in that period. Adalimumab can cost upwards of $84,000 per year while etanercept has a list price of around $72,000 a year. The pharmacy benefit manager WellDyne started covering the test MSRC in February.
Nehad Soloman, MD, a rheumatologist and internist at Midwestern University Arizona College of Osteopathic Medicine in Glendale and a compensated NETWORK-004 investigator, said the MSRC test would be indicated for confirmed RA patients for whom rheumatologists are considering biologic agents, particularly TNFi drugs. “You wouldn’t do it on an RA patient who’s been on several different medications because it doesn’t serve a purpose at that point,” he said.