Novel drugs are innovative new products that have never before been used in clinical practice. Among the 46 that the Food and Drug Administration approved in 2017, 45 could be used in pregnancy. One, cerliponase alfa (Brineura), is indicated for pediatric patients 3 years of age or older, for treatment of late infantile neuronal ceroid lipofuscinosis type 2. It is doubtful that this drug would be used in pregnancy or during breastfeeding.
With the two exceptions noted below, there are no human pregnancy data for these drugs. It is important to consider that although high molecular weight (MW) drugs (for example, greater than 1,000) probably do not usually cross the placenta in the first half of pregnancy, they may do so in late pregnancy. The cited MWs are shown as the nearest whole number. Animal reproductive data are also cited because, although not definitive, they can provide some measure of the human embryo-fetal risk.
Benznidazole (same trade name) (MW 441), given orally, is indicated for pediatric patients aged 2-12 years for treatment of Chagas disease (American trypanosomiasis) caused by Trypanosoma cruzi. However, there are international reports describing its use in pregnancy and breastfeeding. No fetal harm from these exposures were noted. Nevertheless, because of the low MW and the reported animal risk, avoiding the drug during the first half of pregnancy appears to be the best choice. Delafloxacin (Baxdela) (MW 441), a fluoroquinolone antimicrobial given intravenously or orally, is indicated for acute bacterial skin infections. The animal data suggest low risk. However, like other fluoroquinolones, it is contraindicated in pregnancy and should be used only if there are no other alternatives.
Sofosbuvir/velpatasvir /voxilaprevir (Vosevi) (MWs 529, 883, 869), a fixed oral dose combination of three antivirals, is indicated for the treatment of hepatitis C virus infection. The MWs suggest that all three will cross the human placenta. The animal data suggest low risk. Secnidazole (Solosec) (MW 185), given orally, is indicated for the treatment of bacterial vaginosis. It is closely related to metronidazole. No evidence of embryo-fetal toxicity was observed in rats and rabbits, suggesting that the human risk is low. In a report from Brazil, 134 pregnant women with bacterial vaginosis were treated with secnidazole, metronidazole, or tinidazole in the second and third trimesters. Treatment significantly decreased the incidence of premature rupture of membranes, preterm labor, preterm birth, and low birth weight. No fetal harm was reported.
[Note: All of the drugs in this category are best avoided, if possible, in pregnancy and breastfeeding.]
Abemaciclib (Verzenio) (MW 507), an oral inhibitor of cyclin-dependent kinases, is indicated for the treatment of breast cancer. The drug is teratogenic in rats. Acalabrutinib (Calquence) (MW 466) is an oral kinase inhibitor indicated for mantle cell lymphoma. The drug had no effect on the rat embryo-fetus but caused decreased fetal body weights and delayed skeletal ossification in rabbits. Avelumab (Bavencio) (MW 147,000) is given intravenously for the treatment of metastatic Merkel cell carcinoma and metastatic urothelial carcinoma. Animal reproduction studies have not been conducted. However, based on its mechanism of action, fetal exposure may increase the risk of developing immune-related disorders or altering the normal immune response.