DENVER – , according to research presented at the annual meeting of the Consortium of Multiple Sclerosis Centers.
“Depression and anxiety are prevalent comorbidities occurring in up to 54% of patients with multiple sclerosis, and selective serotonin reuptake inhibitors (SSRIs)/serotonin-norepinephrine reuptake inhibitors (SNRIs) are first-line treatments for depression and anxiety disorders,” Robert T. Naismith, MD, of Washington University in St. Louis, and his colleagues reported.
“Coadministration of ozanimod with drugs that increase serotonin could hypothetically lead to serotonin accumulation,” which can increase the likelihood of hypertension. U.S. prescribing information recommends that patients taking both ozanimod and medications that increase norepinephrine or serotonin be monitored for hypertension, an adverse reaction reported in 3.9% of patients receiving ozanimod in the phase 3 trials for relapsing MS.
Clarifying the risk
“It’s important to be aware of potential drug interactions and risks from MS disease modifying therapies,” Lauren Gluck, MD, an assistant professor and director of the division of multiple sclerosis at Montefiore Medical Center/Albert Einstein College of Medicine, New York, said in an interview. Dr. Gluck was not involved in this study but described some of the history that revealed the value of this type of research. For example, the first sphingosine-1-phosphate receptor (S1PR) modulator approved for MS, fingolimod (Gilenya), has a risk of cardiac conduction dysfunction with QTc prolongation, so people taking fingolimod with other medications that prolong QTc, such as SSRIs, need additional monitoring.
“Ozanimod is a newer, more selective S1PR modulator that initially raised concerns about interaction with serotonin-increasing drugs based on in vitro studies,” Dr. Gluck said. “This could mean that people on ozanimod and other serotonin-increasing medicine could be at risk for dangerous events like serotonin syndrome. However, in vitro studies do not always translate to how something affects the human body, so it is not clear how much risk truly exists.”
Examining open-label extension trial data
The researchers therefore evaluated the safety of taking ozanimod and SSRIs or SNRIs in a subset of patients with relapsing MS who participated in the DAYBREAK open-label extension trial. The phase 3 parent trials compared 30 mcg once weekly of intramuscular interferon beta-1a with 0.92 mg of once-daily oral ozanimod and 0.46 mg of once-daily oral ozanimod. In the DAYBREAK open-label extension, 2,256 participants underwent a dose escalation over one week until all reached 0.92 mg of ozanimod, where they remained for an average of just under 5 years of follow-up. Nearly all the participants (99.4%) were White, and two-thirds (66.5%) were female.
The researchers searched the study data for terms related to serotonin toxicity and compared the rates of adverse events related with those terms and the rates of hypertension in the 274 participants who were and the 2,032 participant who were not taking antidepressants at the same time as ozanimod.
They found that 13.9% of patients taking SSRIs or SNRIs experienced at least one treatment-emergent adverse event related to their search criteria, compared with 17.7% of patients not taking SSRIs or SNRIs. Similarly, 9.2% of trial participants not taking SSRIs or SNRIs had hypertension, compared with 4.7% of participants who were taking antidepressants. The authors further noted that “similar trends were observed when 6 weeks after the end date of concomitant SSRIs/SNRI use were included in the ‘on SSRI/SNRI’ analysis period.”
When the researchers searched specifically for three terms directly related to serotonin toxicity – “serotonin syndrome,” “neuroleptic malignant syndrome,” and “hyperthermia malignant” – they did not find any patients who had treatment-emergent adverse events related to those terms.
“SSRIs/SNRIs were freely allowed as concomitant medications in the DAYBREAK open-label extension, and among the patients from SUNBEAM or RADIANCE who were followed for up to 6 years, there have been no reported safety concerns during the concurrent administration of serotonergic antidepressants and ozanimod in patients with relapsing MS as of the data cutoff,” concluded the authors, though they also noted that the overall rate of SSRI and SNRI use was low in the extension trial.