PHILADELPHIA – Hydroxychloroquine (HCQ) isn't any more effective at preventing or delaying the onset of rheumatoid arthritis than placebo, based on interim results of a randomized clinical trial reported at the annual meeting of the American College of Rheumatology. Despite that futility, the percentage of patients who actually went on to develop clinical RA was lower than investigators expected, and the trial supports the use of a key biomarker for identifying RA.
While the StopRA trial was halted early because of futility of the treatment, investigators are continuing to mine the gathered data to deepen their understanding of disease progression and the potential of HCQ to improve symptoms in RA patients, said lead study author Kevin D. Deane, MD, PhD, of the University of Colorado at Denver, Aurora.
Overall, around 35% of the study participants on average developed RA, Deane said. "We were expecting somewhat more," he said. "Teasing out who's really going to progress to RA during a study and who's not is going to be incredibly important."
StopRA enrolled 144 adults who had elevated anti–cyclic citrullinated peptide antibodies (CCP3) levels of at least 40 units (about twice the normal level) but no history if inflammatory arthritis, randomizing them on a 1:1 basis to either HCQ (200-400 mg a day based on weight) or placebo for a 1-year treatment regimen.
The study identified participants through rheumatology clinics, testing of first-degree relatives with established RA, health fairs, blood donors, and biobanks. The interim findings are based on 2 years of follow-up after the last dose.
The study focused on HCQ because it has a relatively low risk profile with good safety and tolerability, is easy to administer, and is relatively low cost, Deane said.
StopRA study failed to meet its primary endpoint: to determine if 1 year of treatment with HCQ reduced the risk of developing inflammatory arthritis and classifiable RA at the end of 3 years in the study population. At the time of the interim analysis, 34% of patients in the HCQ arm and 36% in the placebo arm had developed RA (P = .844), Deane said. Baseline characteristics were balanced in both treatment arms.
The findings also support the use of CCP3 as a biomarker for RA, Deane said.
Now that the trial has been terminated, Deane said investigators are going to review the final data and perform secondary analyses for further clarity on the impact HCQ may have on RA.
"The future analysis should hopefully say if this treatment actually changes symptoms," he said in an interview. "Because, if somebody felt better on the drug or had a milder form of rheumatoid arthritis once they developed it, that could potentially be a benefit."
Deane noted the TREAT EARLIER trial similarly found that a 1-year course of methotrexate didn't prevent the onset of clinical arthritis, but it did alter the disease course as measured in MRI-detected inflammation, related symptoms, and impairment.
"We're hoping to look at those things and hopefully look at biologic changes over time," Deane said of the extended analysis. "We're not sure if the drug was associated with changes in biomarkers yet still didn't halt progression to RA. That might be interesting, because those biomarkers might not be fundamentally related to the disease, but other mechanisms may be. That could give us some insights."
Session moderator Ted Mikuls, MD, a professor of rheumatology at the University of Nebraska Medical Center, Omaha, said further mining of the study data is warranted.
"It's common in a study like that, which took a lot of time and investment, to really take a deep dive into the data to make sure there aren't signals that we're missing," he said in an interview.
One of the challenges with the study may have been patient enrollment, Mikuls noted. "I wonder about the study population in terms of where they recruit patients from. Who's more likely to get RA? Is it patients who already have symptoms? Is it asymptomatic patients from biobanks? If it's arthralgia joint pain patients, maybe by the time you have joint and autoantibody positivity it's too late to have an intervention."
The National Institute of Allergy and Infectious Diseases sponsored the study. Deane disclosed a relationship with Werfen. Mikuls has no relevant disclosures.
This article originally appeared on MDedge.com, part of the Medscape Professional Network.
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Cite this: StopRA Trial: Hydroxychloroquine Doesn't Prevent or Delay Onset of Rheumatoid Arthritis - Medscape - Nov 18, 2022.