Conference Coverage

Interferon treatment does not increase stroke risk in MS


Key clinical point: Pooled data show no increase in stroke risk in MS patients treated with interferon.

Major finding: A trend toward decreased stroke incidence was seen with interferon treatment vs. placebo (IRR, 0.486).

Study details: A review of pooled data from 17 clinical trials and postmarketing surveillance.

Disclosures: This study was supported by Merck KGaA of Darmstadt, Germany. Dr. Gillett is an employee of EMD Serono, the biopharmaceutical division of Merck KGaA.

Source: Sabidó M et al. Neurology. 2018 Apr:90(15 Suppl.):S36.008.



– 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 2017 report on a series of nested case-control studies showed a 1.8-fold increased risk of stroke in relapsing-remitting MS patients who received interferon.

In the new analysis presented at the meeting, there was a trend toward decreased stroke incidence among patients treated with subcutaneous interferon beta-1a. Stroke incidence was 0.025 per 100 patient-years (25 events) in patients treated with subcutaneous interferon beta-1a vs. 0.051 per 100 patient-years (11 events) in patients who received placebo across 17 phase 2-4 clinical trials. The incidence rate ratio (IRR) and hazard ratio for stroke in interferon- vs. placebo-treated patients were 0.486 and 0.496, respectively, reported Dr. Gillett of EMD Serono, Mississauga, Ont.

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.

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