DALLAS – Low or undetectable levels of teriflunomide (Aubagio) occur in women who are sexually active with men taking the drug for relapsing multiple sclerosis, results from a small study demonstrated.
“One of the issues with this particular drug is that it carries a strong pregnancy warning because in animal studies the drug has been teratogenic,”, said in an interview at the meeting held by the Americas Committee for Treatment and Research in Multiple Sclerosis. “The other issue is that it remains detectable in the body for some time. The issue of females taking this drug and conception are well known. There are strong warnings that, if a woman wants to become pregnant, the drug should be removed quickly from the system. But if their male partner is on the drug, does that pose a risk to their female partner? That question has never been addressed in a human study.”
The Food and Drug Administration prescribing information recommends that men wishing to father a child should discontinue use of teriflunomide and undergo the accelerated elimination procedure. It also recommends that female partners wishing to become pregnant should discontinue the drug and undergo an accelerated elimination procedure to verify that the plasma teriflunomide concentration is less than 0.020 mcg/mL.
In an effort to test the risk of female exposure to potentially teratogenic levels of teriflunomide through sexual intercourse, Dr. Guarnaccia, a neurologist with the Multiple Sclerosis Treatment Center at Griffin Hospital in Derby, Conn., and his colleagues recruited 10 couples and compared serum levels of teriflunomide in men with relapsing multiple sclerosis with those of their female partners. Enrollment criteria for men included a diagnosis of relapsing multiple sclerosis, age between 18 and 55 years, treatment with teriflunomide for at least 2 months prior to study entry, and frequency of sexual intercourse with their female partners at least twice a month. Pregnancy was excluded in females, and couples could not use barrier or withdrawal methods of contraception. The couples completed a brief questionnaire and underwent a one-time blood draw for teriflunomide levels either at the investigator’s office or at a LabCorp facility.
The mean age of study participants was 47 years and the mean frequency of intercourse was seven episodes per month. The mean teriflunomide concentration in men was 42.30 mcg/mL (ranged from 10.07 to 142.84 mcg/mL). Six women had teriflunomide below detection levels (0.020 mcg/mL). However, four women had detectable levels that averaged 0.045 mcg/mL (ranging from 0.022 to 0.077 mcg/mL).
“This small study demonstrates that low or undetectable levels of teriflunomide occur in females who are sexually active with males taking teriflunomide for relapsing multiple sclerosis,” the researchers wrote in their poster. They found that women who had low detectable levels of teriflunomide, compared with women with undetectable levels, did not engage in more frequent sexual intercourse nor were their levels associated with higher levels of teriflunomide in their male partners.
“Indeed, one might have expected a positive correlation between serum levels of teriflunomide in females and the frequency or concentration of inoculation in semen from their partners,” the researchers wrote. “While semen levels of teriflunomide were not measured in this study, it might be assumed that serum and semen concentrations of small molecules like teriflunomide are similar.”
The study was supported by a investigator-sponsored research grant from Sanofi-Genzyme. Dr. Guarnaccia reported that he has received speaking honoraria and educational grants from Sanofi-Genzyme, Biogen, Teva, Acorda Therapeutics, Bayer, EMD Serono, and Genentech.
SOURCE: Guarnaccia JB et al. ACTRIMS Forum 2019, .