Pfizer’s Lyrica is facing safety questions after a study published in Neurology this week documented a possible link between the med and birth defects when taken by pregnant women.

Supported by the American Academy of Neurology, the study investigated the pain and antiseizure drug, one of Pfizer’s top sellers, in 164 pregnant women in 7 countries. The team found that for women who took Lyrica during the first trimester, “major birth defects” were three times as likely than for the women who didn’t take antiseizure meds. The results were measured against a group of 656 pregnant women not taking antiseizure drugs.

Seven out of 116 pregnancies (6%) in the Lyrica group had major birth defects, the authors said, compared to a birth defect rate for the larger group of 12 out of 580 pregnancies (2%). The birth defects included problems with the central nervous system, the heart and other organs.

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According to the investigators, the Lyrica group was 6 times more likely to have a CNS “major defect.” The team noted four CNS problems out of 125 pregnancies (3.2%) compared to three out of 570 pregnancies (.5%) for the non-Lyrica arm.

As the authors admit, they can’t draw “definitive conclusions” from the study “since many of the women were taking other drugs that could have played a role in the birth defects and because the study was small.” However, the research--which will need to confirmed with larger tests--signals “that there may be an increased risk for major birth defects after taking pregabalin during the first trimester of pregnancy," author Ursula Winterfeld wrote in a statement.

In an email to FiercePharma, Pfizer cited the study's “significant limitations," saying it “was small, did not account for other medical conditions or medications, and the women taking Lyrica had higher rates of smoking and diabetes, all of which can negatively affect pregnancy outcomes.”

Approved by the FDA to treat epilepsy, fibromyalgia and neuropathic pain, Lyrica is also used off-label to treat anxiety and other mental health issues.

A stalwart for Pfizer’s pharma business for years, Lyrica brought in $3.6 billion last year. The company, which has been working to defend from generics, got into hot water last September in the U.K. after losing a key patent fight. According to a judge, letters it wrote to doctors and pharmacies who would introduce a generic version of Lyrica were "calculated to have a chilling effect on the willingness of pharmacies to stock and dispense generic pregabalin."

The drug was one among many by Pfizer whose prices jumped this year despite ongoing public pressure against drug price hikes. According to reports, its price jumped 9% to ring in the new year.

- here's the release

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