Fetal Outcomes Largely Unaffected by Antiseizure Medication Lacosamide

Paula E. Voinescu, MD, PhD

Using data from spontaneous and solicited reports, findings from a new analysis showed that lacosamide (Vimpat; UCB Pharma), an antiseizure medication (ASM), was safe to use during pregnancy, with most exposed pregnancies resulting in live births. Lacosamide, listed as a Pregnancy Category C medication, had no new safety concerns associated with its use.¹

Presented at the 2023 American Epilepsy Society (AES) annual meeting, held December 1-5, in Orlando, Florida, the analysis comprised of 213 cases of lacosamide-exposed pregnancy to evaluate fetal outcomes. This included prospective reports available in the UCB Pharma global safety database from spontaneous sources such as routine clinical settings or solicited reports from interventional clinical studies and non-interventional post-marketing studies. The analysis excluded data from registries and published data from NIS and non-UCB Pharma studies.

Led by Paula E. Voinescu, MD, PhD, a neurologist at Brigham and Women’s Hospital, there were 202 individual maternal exposure pregnancies with 204 reported pregnancy outcomes (2 twin pregnancies in the polytherapy group). During pregnancy, 21.8% (44 of 202) patients received lacosamide as a monotherapy and 78.2% (158 of 202) received polytherapy. Between the 2 groups, the proportion of live births was numerically higher (84.1% vs 76.3%) and the proportion of all abortions was numerically lower (15.9% vs 22.5%) for those on lacosamide monotherapy.

Most patients on lacosamide monotherapy (88.6%) and polytherapy (90.5%) received treatment during the first trimester, at a mean maximum dose of 352.9 (SD, 191.9) mg/day and 297.6 (SD, 119.1) mg/day, respectively. Of those on polytherapy, more than half (57.0%) were on 1 concomitant ASM, with levetiracetam (51.9%) and lamotrigine (27.6%) as the most commonly used. Notably, 41.8% (66 of 158) of these patients were on at least 2 concomitant ASMs.

On fetal outcomes, 2.3% (1 of 44) and 6.9% (11 of 160) of patients on monotherapy and polytherapy, respectively, reported congenital malformations. Preterm delivery was recorded in 10.8% (4 of 37) of live births with maternal exposure to lacosamide monotherapy and 9.0% (11 of 122) of live births with maternal exposure to lacosamide polytherapy. For the monotherapy group, small for gestational age was reported in 2.7% (1 of 37) and low birth weight was found in 13.5% (5 of 37). The polyneuropathy group showed similar, but slightly lower rates of these outcomes, as small for gestiational age was found in 2.5% (3 of 122) of patients and low birth weight reported in 8.2% (10 of 122) of live births.

Lacosamide is currently approved for use as a monotherapy or with other seizure medicines to treat focal seizures in adults and children 4 years of age or older. Additionally, its approved as a liquid for injection in those with focal seizures 17 years and older for temporary use when a person is unable to take an oral form. It is listed as a Pregnancy Category C medication, which advises that patients take caution, but that the benefits of the medicine may outweigh the potential risks.²

Earlier this year, data published in Seizure: European Journal of Epilepsy on the use of lacosamide in pregnant women showed no evidence for substantial embryotoxic or teratogenic effects. The study comprised of several newer ASMs with marketing authorization since 2005 who reported to the Embryotox Center of Clinical Teratology and Drug Safety in Pregnancy between 2004 and 2019. Among 55 prospectively and 10 retrospectively ascertained lacosamide exposed pregnancies, findings showed no increased risks of major birth defects or spontaneous abortion.³

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REFERENCES
1. Voinescu PE, Vadlamudi L, Bourikas D, Werhahn K, Kumke T, Schmitz B. Pregnancy outcomes following exposure to lacosamide: prospective data from spontaneous and solicited reports. Presented at: AES 2023; December 1-5; Orlando, FL. POSTER 2.29.
2. Lacosamide. Epilepsy Foundation. https://www.epilepsy.com/tools-resources/seizure-medication-list/lacosamide. Updated November 16, 2023. Accessed November 30, 2023.
3. Hoeltzenbein M, Slimi S, Fietz AK, et al. Increasing use of newer antiseizure medication during pregnancy: an observational study with special focus on lacosamide. Seizure: European Journal of Epilepsy. 2023;107:107-113. doi:10.1016/j.seizure.2023.02.015