Moving forward in systemic sclerosis
Indeed, in order to move forward in developing better treatment for SSc, it is important to have the best possible means for assessing the effects of the potential new treatments, Dr. Spiera said.
“The mRSS is a good, reliable outcome measure in terms of intra- and inter-rater reliability, and we know it has meaning in the real world; in a patient with rapidly progressive skin thickening and a skin score that is getting higher and higher, we know they have worse prognosis in terms of function and even survival,” he said. “On the other hand, it’s just one piece of this very complicated story when you’re dealing with patients with systemic sclerosis, some of whom can have important internal organ involvement and not even have skin involvement.”
The main challenge with the skin score is how it performs in clinical trials when it comes to demonstrating whether a drug works, he added.
“This is particularly relevant in an era where our better understanding of the disease has led to candidate therapeutic agents that we have reason to think might work, but where clinical trials haven’t shown a significant difference between the groups using the skin score.”
Conversely, there have been studies in which skin scores improve, but the patient is doing terribly, he noted.
“That patient would not be [shown to be] doing well using the CRISS,” he said, explaining that the complex formula used to determine the CRISS score, which is “heavily weighted toward skin score,” allows for an overall score that is “greater than the sum of its parts.” That is, if a patient is improving in multiple domains indicating that the patient is responding to therapy, more credit is given for each of those parts.
“So my sense, and I think it’s the consensus in the community of clinical investigators, is that the skin score is not adequately sensitive to change in the context of a trial and doesn’t capture the disease holistically enough to be the optimal measure for scleroderma clinical trials,” he said. “We think the CRISS score works better in terms of capturing improvement in the course of a trial, and also in capturing other outcomes that are really, really important to patients and to their physicians, like disability or lung function.”
The hope is that, given the evidence, regulatory agencies will look favorably on the ACR CRISS as an outcome measure in clinical trials moving forward, and that understanding of its use and value will increase across the rheumatology community, he said.
Dr. Spiera has received research grants, consulting fees, and/or other payments from many companies involved in SSc treatments, including Roche/Genentech, which markets tocilizumab, and Corbus Pharmaceuticals, which is developing lenabasum.
Dr. Khanna is a consultant to Roche/Genentech and Bayer, which markets riociguat, and other companies. He has received research grants from Bayer, Bristol-Myers Squibb (which markets abatacept), and Pfizer. The ASSET trial he presented was sponsored by an NIH/NIAID Clinical ACE grant and an investigator-initiated grant by Bristol-Myers Squibb.
Dr. Distler has a consultancy relationship and/or has received research funding from Bayer, Roche/Genentech, and other companies. He also has a patent for a treatment for systemic sclerosis.
Dr. Zheng reported having no disclosures.
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