Pravastatin, proton-pump inhibitors, metformin, micronutrients, and biologics: new horizons for the prevention or treatment of preeclampsia.

There has been increasing research momentum to identify new therapeutic agents for the prevention or treatment of preeclampsia, drugs that can affect the underlying disease pathophysiology. Molecular targets of candidate treatments include oxidative stress, antiangiogenic factors, and the angiotensin, nitric oxide, and proinflammatory pathways. The proposed treatments undergoing preclinical and clinical trial evaluation are thought to act on placental or endothelial disease or both. Most have adopted the pragmatic strategy of repurposing drugs. Of all the therapeutic agents proposed, pravastatin has received the most interest. There are preclinical studies showing that it has pleiotropic actions that favorably impact on multiple molecular targets and can resolve a preeclampsia phenotype in many animal models. An early phase clinical trial suggests that it may have therapeutic activity. Several large prevention trials are planned or ongoing and, when completed, could definitively address whether pravastatin can prevent preeclampsia. Proton-pump inhibitors, metformin, and sulfasalazine are other drugs with preclinical evidence of multiple molecular actions that could resolve the pathophysiology of preeclampsia. These agents are also currently being evaluated in clinical trials. There have been many recent preclinical studies identifying the potential of numerous natural compounds to treat preeclampsia, such as plant extracts and micronutrients that have potent anti-inflammatory or antioxidant activity. Recent preclinical studies have also proposed novel molecular-targeted strategies, such as monoclonal antibodies targeting tumor necrosis factor alpha, placental growth factor, and short interfering RNA technology, to silence the gene expression of soluble fms-like tyrosine kinase-1 or angiotensinogen. Other treatment approaches that have transitioned to human trials (ranging from single-arm to phase III trials that have been completed or are ongoing) include folic acid, nitric oxide donors (such as L-arginine), recombinant antithrombin III, digoxin immune antigen-binding fragment, and melatonin. There have been case series showing the removal of circulating soluble fms-like tyrosine kinase-1 may help stabilize the disease and prolong pregnancy. Interestingly, there are case reports suggesting that monoclonal antibody eculizumab (complement inhibitor) may have therapeutic potential. If new agents are discovered that are proven to be effective in preventing or treating preeclampsia, the potential to improve global maternal and perinatal health will be significant.

Effects of gefitinib, an epidermal growth factor receptor inhibitor, on human placental cell growth.

OBJECTIVE: Placenta has the highest expression of epidermal growth factor (EGF) receptor of all tissues, a cell signaling pathway promoting survival and growth. Therefore, EGF receptor inhibition could potentially treat ectopic pregnancy. We undertook preclinical studies to examine whether gefitinib (orally available EGF receptor inhibitor) with or without methotrexate inhibits placental cell growth. METHODS: Gefitinib and methotrexate were added to placental cells and their ability inhibit cell growth, block EGF receptor signaling, and induce apoptosis (programmed cell death) was examined. They were also administered to two animal mouse models to examine their effects on placental tissue in vivo. RESULTS: Epidermal growth factor receptor was highly expressed in placental tissue from ectopic pregnancies. Combining gefitinib with methotrexate potently inhibited growth of placental cells, including placental cell lines (JEG3, BeWo cells) and cells isolated from first-trimester placenta. These drugs were additive in blocking EGF receptor signaling and inducing apoptosis. Gefitinib and methotrexate administered together were more potent in decreasing the volume of human placental cells xenografted subcutaneously onto mice compared with either alone. By day 19 after xenografting, mean (± standard error of the mean), xenograft volumes were: 821 (± 68) mm after gefitinib treatment, 901 (± 204) mm after methotrexate treatment, and 345 (±137) mm after both drugs were given (P<.01 for both comparisons of single therapy compared with combination therapy). Combining these agents doubled rates of fetal resorption in pregnant mice compared with each drug alone. CONCLUSION: Combining gefitinib with methotrexate potently inhibits placental cell growth in vitro and in mouse models. The combination may have potential in treating ectopic pregnancies.