Lupus in Remission Flares More Often When Reducing, Stopping HCQ

Tara Haelle

November 09, 2021

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.

"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," 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.

Results

The overall cohort examining reduction of HCQ dose included 564 patients who reduced their dose, contributing 1,063 person-years of data, and 778 matched patients who started HCQ at the same time but continued HCQ maintenance therapy without a dose reduction, contributing 1,242 person-years. The average duration of HCQ use since time zero in this cohort was 3.4 years.

Before stratifying for disease activity, the group who reduced their therapy experienced 40 first flares per 100 person-years, compared with 31.9 first flares per 100 person-years on maintenance therapy. Those who reduced HCQ had a 20% greater risk of flares than did those who continued it (adjusted hazard ratio, 1.2). However, when those in remission were compared with those not in remission – independent of disease activity level – patients in remission were twice as likely to experience a flare if they reduced their HCQ dose (aHR, 2.14).

In the discontinuation cohort, 389 patients who stopped HCQ therapy contributed 657 person-years, and 577 matched patients who continued HCQ maintenance therapy contributed 924 person-years. The average duration of HCQ use since time zero in this cohort was 4.2 years. Before stratifying for disease activity, the average number of first flares per 100 person-years was 41.3 in the HCQ discontinuation group and 30 in the HCQ maintenance group, resulting in a 56% higher risk of flares for those who stopped HCQ, compared with patients who continued HCQ (aHR, 1.56). Looking only at those in remission, patients were nearly three times more likely to experience a flare if they stopped HCQ than were patients not in remission who continued a maintenance dose (aHR, 2.77).

Patient Age Is an Important Consideration

Overall, these findings are not surprising, said Jill P. Buyon, MD, director of the division of rheumatology and of the Lupus Center at NYU-Langone Health in New York. Buyon is not involved in the current study but is studying discontinuation of HCQ in older adults with lupus.

Dr Jill Buyon

"It has been already shown that when lupus patients discontinue HCQ, flares are more likely, but does this apply to all age groups?" Buyon asked in an interview. "Data are essential to more accurately weigh the balance between accumulating ocular exposure, the explosion of new tools to assess retinal injury, and the risk of disease flare in a population that may have more stable/quiescent disease than younger patients."

Although HCQ's track record with infection risk is consistently better than that of more immunosuppressive drugs and is very safe during pregnancy, Buyon said her "ophthalmology colleagues persistently emphasize the risk of retinal accumulation of drug and ocular toxicity over time." She referenced a recent case-control study in which overall prevalence of HCQ retinopathy was 7.5%, and greater for patients taking more than 5 mg/kg of HCQ or who used HCQ for more than 10 years.

"Risk escalates with continued use, and evaluation by sensitive approaches such as multifocal electroretinography suggests nearly a third of patients accrue retinal damage," Buyon said. "As the longevity of patients improves and comorbidities such as renal insufficiency (which affects HCQ clearance) may increase, the ratio of efficacy to toxicity would be expected to decrease." Further, the fact that disease activity may wane as people age means that rheumatologists treating older adults need to address a critical question, she said: "Can HCQ be safely withdrawn? This question is important in the context of an even broader concern regarding management of SLE in the elderly population, a topic which has received minimal attention."

The study is limited by its observational design and the fact that the intervention was not randomly allocated, although the researchers attempted to adjust for confounders. Bernatsky also noted that mild flares might have been missed, and the researchers did not evaluate HCQ levels or adherence, nor did the data set include physicians' or patients' explicitly stated reasons for HCQ reduction or discontinuation.

"We estimated that 5% of patients may have reduced HCQ therapy as result of the AAO [American Academy of Ophthalmology] guidelines, 55% because of low disease activity state, and the remainder (40%) for other reasons, possibly intolerance or patient preference," the researchers noted in their abstract. "Among those who discontinued HCQ, 4% had retinal changes of concern, 15% were in clinical remission, and the remainder stopped for unknown reasons, possibly intolerance or patient preference."

Buyon also pointed out that the cohort was initially intended for studying cardiovascular risk and not designed to capture all visits during each year of follow-up.

"Thus, while hospitalizations would be well captured, not all flares, particularly those not severe, would be captured, and thus we may not have the complete picture," she said, reiterating Bernatsky's point that mild flares may have been missed.

"Clearly, this is a very important topic for the management of our patients, particularly those who are elderly and may have already reaped the benefits of hydroxychloroquine," Buyon said. "Of course, we have to be mindful of the potential benefit with regard to blood clotting and lipid lowering. Nevertheless, accumulated ocular toxicity and cardiac issues such as cardiomyopathy may emerge to tip the balance after years of accumulated drug exposure."

The research was funded by the Canadian Institute of Health Research, the Singer Family Fund for Lupus Research, and the SLICC Group. Bernatsky had no disclosures. Buyon noted that she has an R34 NIH planning grant to study the safety of withdrawal of hydroxychloroquine in elderly lupus patients that is relevant to this study.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.

processing....