LOS ANGELES – Patients with multiple sclerosis who are treated with subcutaneous interferon beta-1a have no increase in stroke risk, compared with those treated with placebo, according to pooled data from clinical trials and a safety database analysis.
Studies have shown that MS patients have a greater risk of stroke, compared with the general population, but the data with respect to the risk of stroke following interferon treatment are limited, Alan Gillett, PhD, explained in his presentation at the annual meeting of the American Academy of Neurology. He noted that a 2017on a series of nested case-control studies showed a 1.8-fold increased risk of stroke in relapsing-remitting MS patients who received interferon.
Further, no significant difference in stroke incidence was seen between the treatment and placebo groups based on treatment duration, Dr. Gillett said. The IRR in patients treated for less than 2 years was 0.602 vs. 0.469 in those treated for 2 or more years.
“The incidence rate ratio [in both groups] was very comparable to that overall, so this indicates that treatment duration had little impact on the incidence rate of stroke,” he said.
The same was true in an analysis based on dose; the IRRs were similar in those exposed to 44 mcg vs. placebo, and in those receiving any dose vs. placebo, he noted.
The analysis is based on reports of 569 cerebrovascular events occurring over 19 years (2.7 per 10,000 patient-years) in 1,594,414 patient-years of follow-up through May 22, 2017, in the Global Patient Safety Database.