POS0705 DILEMMA OF BELIMUMAB THERAPY (DIS) CONTINUATION DURING PREGNANCY: RESULTS OF A RETROSPECTIVE STUDY IN EUDRAVIGILANCE

Abstract

BackgroundActive systemic lupus erythematosus (SLE) and nephritis due to SLE contribute to poor pregnancy outcomes. (1, 2) A meta-analysis has shown a relative risk of 1.51 for miscarriage in SLE patients compared to women without SLE. (3) The risk is even higher if the disease is active during pregnancy (around 3-fold increase in pregnancy loss). (4) Corticosteroids, azathioprine, hydroxychloroquine, ciclosporine and tacrolimus are considered safe treatments. (5) However, these treatment options may still not be sufficient in patients poorly responsive to conventional therapies or patients who suffer from nephritis. (6) The only biologic authorized for SLE up to this date, belimumab, is currently not recommended for use during pregnancy due to lack of data.Provided that the health of the child begins with the health of the mother, pregnant patients, face the dilemma of cessation or continuation of belimumab. If belimumab is stopped there will be a risk of SLE flare and its consequences for mother and foetus. Continuation is also not optimal because the lack of knowledge on safety for use during pregnancy.ObjectivesTo compare the reported foetal outcomes in SLE patients who stopped scheduled belimumab within the first trimester (group A) and who continued scheduled belimumab during the first trimester or thereafter (group B).MethodsAll belimumab-exposed pregnancy-related reports, were extracted from the EudraVigilance (EV) database until March 11th 2021. After case review, repeated cases, uninformative reports, non-medical elective abortions and foetal chromosomal abnormalities were excluded. Included pregnancies were divided into two groups (group A and B, as described above). Foetal outcomes were divided into live birth or foetal death (due to miscarriage or still birth) and were compared between both groups. Furthermore, neonatal outcomes, such as reporting rates of pre-term birth, low birth weight and major congenital malformations (CMs) were compared.ResultsNo statistical difference in foetal death was observed between group A and B (reporting rates: 46.4% and 52.4%, respectively; p-value>0.05). Occurrence of major CMs, pre-term birth and low birth weight was higher - though not statistically different- in group A (Table 1).Table 1.Neonatal characteristics of live born children (including twin pregnancies)Live birthsStopped (group A); (n=37)Continued (group B); (n =10)Total; (n=47)Gestational age at birth, median (IQR), weeks37.1 (35.5, 40.0)38.2 (36.4, 39.1)37.6 (36.0, 39.4)Weight, median (IQR), grams2749 (2268, 3200)2975 (2700, 3175)2835 (2406-3175)Preterm birth*; n (%)16 (43.2)4 (40.0)20 (42.5)Low birth weight*; n (%)9 (24.3)0 (0.0)9 (19.4)ConclusionBased on our data belimumab continuation during first trimester or thereafter does not result in higher reporting of foetal death. Therefore, continuation might be even preferable if the pregnancy is already exposed to belimumab. Since the analysis is based on spontaneous reports / retrospective data, additional studies are needed to confirm the results.