Study has broad implications
MAUI, HAWAII – , Orrin M. Troum, MD, said at the 2019 Rheumatology Winter Clinical Symposium.
Bruce Jancin/MDedge News
Dr. Alvin F. Wells (left) and Dr. Orrin M. Troum
He cited what he considers to be a practice-changing, prospective, observational, proof-of-concept study presented by John Botson, MD, at the 2018 annual meeting of the American College of Rheumatology.
Dr. Botson, a rheumatologist at Orthopedic Physicians Alaska, in Anchorage, reported on nine patients with refractory tophaceous gout placed on an 8-mg infusion of pegloticase every 2 weeks as third-line therapy. But 1 month beforehand he put them on oral methotrexate at 15 mg once weekly along with folic acid at 1 mg/day in an effort to prevent the development of treatment-limiting anti-pegloticase antibodies. It’s the same strategy rheumatologists often use when patients with rheumatoid arthritis on a tumor necrosis factor inhibitor begin to develop anti-drug antibodies.
At the time of the ACR meeting, all nine patients had received at least nine infusions, and six had received at least 12 infusions over the course of 6 months. The response rate was 100%, defined as more than 80% of serum uric acid levels being below 6.0 mg/dL. All patients stayed on methotrexate with no dose adjustment. And there were no infusion reactions. In contrast, the response rate in the randomized trials of pegloticase was only 42%, and 26% of pegloticase recipients experienced infusion reactions within 6 months.
“Although this is not [Food and Drug Administration] approved, it makes a lot of sense. From my standpoint, this is something that I’m doing now for my patients starting on pegloticase if there’s no contraindication to using methotrexate,” said Dr. Troum, a rheumatologist at the University of Southern California in Los Angeles.
“I’ve been doing this, too. This really did change my practice,” added his fellow panelist Alvin F. Wells, MD, PhD, director of the Rheumatology and Immunotherapy Center in Franklin, Wisc.
When they asked for a show of hands, only a handful of audience members indicated they are now using methotrexate in conjunction with pegloticase in their tophaceous gout patients.
Dr. Wells said his sole reservation about the practice involves using methotrexate in patients with an elevated creatinine level. What about using azathioprine or corticosteroids instead? he asked.
Dr. Troum replied that he monitors those patients carefully but sticks with the methotrexate because it’s only for a few months, which is the time frame in which patients are especially vulnerable to experiencing loss of response to pegloticase due to development of anti-drug antibodies.
Dr. Botson, who was in the Maui audience, rose to give a study update. With additional follow-up, he said, there has still been no signal of loss of response to pegloticase coadministered with methotrexate.
“A lot of us are starting to feel like immunosuppression, whether it’s with methotrexate or something else, is standard of care now,” according to the rheumatologist.
As to prescribing methotrexate in gout patients with renal insufficiency, he continued, he and his colleagues have given the matter quite a bit of thought.
“You’re talking about using methotrexate for 6 months in most of these cases. A lot of the patients who have really bad tophaceous gout already have renal insufficiency, and in the short term we haven’t really seen any problems with that. We work closely with a nephrologist on those cases. And a lot of nephrologists swear – although I don’t think the data are there – that they actually improve their renal function when we start to treat their tophaceous gout,” Dr. Botson said.
Dr. Troum and Dr. Wells reported serving as consultants to and on speakers bureaus for numerous pharmaceutical companies.