Continuation of hydroxychloroquine (HCQ) when a patient’s systemic lupus erythematosus (SLE) is in remission or has very low disease activity is linked to a lower risk of flares than is reducing or stopping the antimalarial drug, according to new research presented at the virtual annual meeting of the American College of Rheumatology.
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“Though HCQ is a cornerstone SLE drug, physicians and patients often consider lowering or stopping the drug during remission or low disease activity in order to limit long-term toxicity,” Sasha Bernatsky, MD, PhD, a professor of rheumatology at McGill University in Montreal, told attendees. Her group’s findings revealed a 20% increased risk of flares in those who reduced their HCQ dose and a 56% greater risk of flares in those who discontinued HCQ, compared with those who continued on a maintenance dose.
“I’m going to be using these results in discussions with my patients regarding what the potential implications are of lowering or stopping hydroxychloroquine,” Dr. Bernatsky told attendees. “I think, in the end, this information should be in their hands so that they can be the ones to make these decisions with us, and, of course, given the significant flare rates even in remission, we need to keep on working on optimizing lupus treatments.”
Study details
The researchers analyzed prospective data from 1,460 patients enrolled in the Systemic Lupus Erythematosus International Collaborating Clinics (SLICC) cohort, which includes 33 sites across Europe, Asia, and North America. Patients in this cohort undergo annual follow-ups after enrollment within 15 months of their diagnosis. The study population was 89% female and 52% white. All participants either had low disease activity, defined as a score of 4 or lower on the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) and/or as a prednisone dose no greater than 7.5 mg/day, or were in complete remission, defined as a 0 on SLEDAI-2K while receiving no therapy, including no prednisone or immunosuppressives in the past year.
In addition to adjusting for sex, race/ethnicity, age, education, and geographic residence, the researchers took into account baseline SLE duration, renal damage, body mass index, smoking status, and use of prednisone, immunosuppressives, and biologics. For the outcome of time to first flare, the researchers analyzed those who discontinued HCQ separately from those who reduced the dose, comparing each to those who continued HCQ maintenance therapy. The researchers defined first flare as either hospitalization because of SLE, increased disease activity (at least 4 points on the SLEDAI-2K), or therapy augmentation with steroids, immunosuppressives, antimalarials, or biologics.
Within each cohort, patients who reduced or stopped HCQ therapy were matched to patients who continued HCQ maintenance therapy based on duration of HCQ since time zero, the point at which participants were considered at risk for SLE flares. In the reduction cohort, time zero was the date of a participant’s first HCQ reduction; in the discontinuation cohort, time zero was the date a participant stopped the therapy. Because of the study’s design and reliance on person-years of exposure, it was possible for a single participant to contribute data to more than one cohort.