Immune Checkpoint Inhibitor Use During Pregnancy and Outcomes in Pregnant Individuals and Newborns.

Importance: With the widespread use of immune checkpoint inhibitors (ICIs), concerns about their pregnancy outcomes through maternal exposure have emerged, and clinical comparative data are lacking. Objective: To assess the risk of pregnancy-, fetal-, and/or newborn-related adverse outcomes associated with exposure to ICIs compared with exposure to other anticancer agents. Design, Setting, and Participants: In this cohort study, all reports mentioning a pregnancy-related condition and an antineoplastic agent (Anatomical Therapeutic Chemical classification group L01) used for a cancer indication registered in the World Health Organization international pharmacovigilance database VigiBase up to June 26, 2022, were extracted. Exposure: Anticancer agents, including ICIs, used during pregnancy for a cancer indication. Immune checkpoint inhibitors included blockers of programmed cell death 1 (PD1) or its ligand (PD-L1) or cytotoxic T-lymphocyte-associated protein 4 (CTLA4). Main Outcomes and Measures: The main outcome was the reporting odds ratio (ROR) for maternal, fetal, or newborn complications in patients treated with ICIs vs any other anticancer drug. Adverse events, categorized into 45 individual maternofetal adverse outcomes, were directly mapped to Medical Dictionary for Regulatory Activities preferred terms in VigiBase. Results: A total of 3558 reports (ICI: 91 [2.6%]; other anticancer drugs: 3467 [97.4%]) were included in the analysis. In the ICI group, most reports were from the US (60 [65.9%]), and the mean (SD) patient age was 28.9 (10.2) years; in 24 of 55 reports with data on cancer type (43.6%), patients were treated for melanoma. The molecules involved in the ICI group were anti-PD1 (58 reports [63.7%]), anti-PD1 plus anti-CTLA4 (15 [16.5%]), anti-CTLA4 (13 [14.3%]), anti-PD-L1 (4 [4.4%]), and anti-PD1 plus anti-lymphocyte activation gene 3 (1 [1.1%]). An ICI was used in combination with a non-ICI anticancer agent in 10 participants (11.0%). Compared with other anticancer drugs, none of the 45 adverse outcomes identified were overreported in the group exposed to ICIs. However, preterm birth was significantly overreported for the anti-PD1 plus anti-CTLA4 combination compared with other anticancer drugs (12 of 15 [80.0%] vs 793 of 3452 [23.0%]; ROR, 13.87; 95% CI, 3.90-49.28; P < .001) but not for anti-PD-L1 or anti-CTLA4 monotherapy. Three reports of possibly immune-related maternofetal events were identified: 1 case of maternal antiphospholipid syndrome leading to spontaneous abortion, 1 case of pneumonitis leading to neonatal respiratory distress syndrome and death, and 1 case of transient congenital hypothyroidism. Conclusions and Relevance: In this cohort study of 91 individuals exposed to ICIs during pregnancy, ICI exposure was not associated with overreporting of specific adverse pregnancy, fetal, and/or newborn outcomes compared with other anticancer treatments. However, due to possible rare immune-related neonatal adverse events, ICI use in pregnant women should be avoided when possible, especially the anti-PD1 plus anti-CTLA4 combination.

Treatments During Pregnancy Targeting ERBB2 and Outcomes of Pregnant Individuals and Newborns.

Importance: Targeted therapies directed against ERBB2 are the cornerstone of medical treatment for ERBB2-positive breast cancers but are contraindicated during pregnancy. Objectives: To describe the association of exposure to anti-ERBB2 agents during pregnancy with pregnancy and fetal or newborn outcomes, and to compare the risk and types of adverse outcomes reported more frequently in this context than after exposure to other anticancer agents. Design, Setting, and Participants: For this case-control study, All reports with a pregnancy-related condition and an antineoplastic agent (Anatomical Therapeutic Chemical classification group L01) registered in the World Health Organization international pharmacovigilance database VigiBase up to June 26, 2022, were extracted. All reports with a pregnancy, an antineoplastic treatment during pregnancy, and a cancer were retained. Reports with anticancer agents prescribed for nononcologic purposes were not included. Exposure: The exposure group was defined as reports that mention anti-ERBB2 agents compared with exposure to other anticancer agents. Main Outcome and Measures: The main outcome was the reporting odds ratio (ROR) for maternofetal complications in the group exposed to anti-ERBB2 agents compared with other anticancer agents, as determined using a disproportionality analysis. Results: A total of 3558 reports (anti-ERBB2 agents, 328; other anticancer agents, 3230) were included in the analysis. In the group exposed to anti-ERBB2 agents, most reports were from the US (159 [48.5%]), the mean (SD) age of participants was 30.8 (10.4) years, and 209 patients (97.7%) were treated for breast cancers. The molecules most frequently involved in cases with anti-ERBB2 agents were trastuzumab (n = 302), pertuzumab (n = 55), trastuzumab-emtansine (n = 20), and lapatinib (n = 18). The outcomes overreported in these cases included oligohydramnios (ROR, 17.68 [95% CI, 12.26-25.52]; P < .001), congenital respiratory tract disorders (ROR, 9.98 [95% CI, 2.88-34.67]; P < .001), and neonatal kidney failure (ROR, 9.15 [95% CI, 4.62-18.12]; P < .001). Sensitivity and multivariable analyses found similar results. Toxic effects were also significantly overreported for trastuzumab-emtansine (cardiovascular malformation: ROR, 4.46 [95% CI, 1.02-19.52]) and lapatinib (intrauterine growth restriction: ROR, 7.68 [95% CI, 3.01-19.59]). Conclusions and Relevance: In this case-control study of 328 individuals exposed to anti-ERBB2 agents during pregnancy, exposure was associated with a severe specific adverse pregnancy and fetal or newborn outcomes compared with exposure to other anticancer treatments.