Dr Yusuf Yazici Discusses Disease Activity Assessment Tools in RA, Osteoarthritis

Disease activity assessments can help physicians treat to targets, but in some areas those targets have not been set yet, said Yusuf Yazici, MD, clinical associate professor in the Department of Medicine at NYU Langone Health.

Transcript

How can the tool chosen for disease activity assessment impact treatment decisions?

We have the same issue and a lot more solutions in rheumatoid arthritis….When the biologic agents were first developed for rheumatoid arthritis and we were able to start getting true remission numbers—about 50% of our patients—it became very important to define what’s disease activity, what’s remission.

So, what the rheumatoid arthritis world has done is they’ve looked at multiple different measures of joint counts, patient function, patient pain global assessment and came up with composite scores. In osteoarthritis, we have the WOMAC [Western Ontario and McMaster Universities Osteoarthritis Index] tool, which the questionnaire that the patients fill out that reflects their improvement about their current situation with pain and function and stiffness, which has been a good tool to use in clinical trials.

And the OARSI, the Osteoarthritis Research Society International, has also developed more of a threshold response that’s called the OARSI response, which requires 20% improvement in pain or function with 20 units of actual improvement or OARSI strict response, which is 50% improvement in the same measures. Now, these are good thresholds and goals to aim, not just in randomized controlled trials, where we can show that the drug is working better than the placebo, but also to see indications more strict, for example, when does the patient need another injection.

In our case, more than 70% of the patients reach that OARSI strict response, so those patients probably, in my opinion, we have to finish up our studies, go out to a year, for example, after injection. But others might require 6 months. It gives the physician some objective measure to see how much benefit the patient is getting. How long they need to be on the medication, if this was a daily tablet or injection, like for osteoarthritis, and also treating to a target, because what we know, if the patient has a certain type, just as for diabetes we have the hemoglobin A1C [glycated hemoglobin] going to that target improves patient outcomes long term. In osteoarthritis, those targets haven’t been set yet, but there’s both OARSI, OMERACT [Outcome Measures in Rheumatology], which are groups that work on outcomes measures, are working to define those. And those will be very helpful, not just for the physicians, and the patients also, when we have effective therapies, hopefully approved.