IMPORTANCE A critical question in health care is the extent of scientific evidence that should be required to establish that a new therapeutic agent has benefits that outweigh its risks. Estimating the costs of this evidence of efficacy provides an important perspective. OBJECTIVE To estimate costs and assess scientific characteristics of pivotal efficacy trials that supported the approval of new therapeutic agents by the US Food and Drug Administration (FDA) from 2015 to 2016. DESIGN AND SETTING This study identified 59 novel therapeutic drugs using the annual summary reports from the FDA Center for Drug Evaluation and Research. ClinicalTrials.gov, FDA reviews, and peer-reviewed publications that were publicly available in 2017 were used to identify 52 characteristics of each efficacy trial. Costs were calculated with a global clinical trial cost assessment tool available to contract research organizations and pharmaceutical sponsors. MAIN OUTCOMES AND MEASURES Estimated mean cost and 95% CIs based on industry benchmark data from 60 countries. Measures of trials' scientific characteristics included trial design (no control group, placebo, and active drug), end point (surrogate outcome, clinical scale, and clinical outcome), patient enrollment, and treatment duration. RESULTS A total of 138 pivotal clinical trials provided the basis for approval of 59 new therapeutic agents by the FDA from 2015 to 2016, with a median estimated cost of $19.
In the ischemic brain, reperfusion with tissue plasminogen activator (tPA) sometimes causes catastrophic hemorrhagic transformation (HT); however, the mechanism remains elusive. Here, we show that the basement membrane, and not the endothelial cells, is vulnerable to ischemic/reperfusion injury with tPA treatment. We treated a spontaneously hypertensive rat model of middle cerebral artery occlusion (MCAO) with vehicle alone, tPA alone, or a free radical scavenger, edaravone, plus tPA. Light and electron microscopic analyses of each microvascular component revealed that the basement membrane disintegrated and became detached from the astrocyte endfeet in tPA-treated animals that showed HT. On the other hand, edaravone prevented the dissociation of the neurovascular unit, dramatically decreased the HT, and improved the neurologic score and survival rate of the tPA-treated rats. These results suggest that the basement membrane that underlies the endothelial cells is a key structure for maintaining the integrity of the neurovascular unit, and a free-radical scavenger can be a viable agent for inhibiting tPA-induced HT.
Angiogenesis occurs in a wide range of conditions. As ischemic tissue usually depends on collateral blood flow from newly produced vessels, acceleration of angiogenesis should be of therapeutic value to ischemic disorders. Indeed, therapeutic angiogenesis reduced tissue injury in myocardial or limb ischemia. In ischemic stroke, on the other hand, angiogenic factors often increase vascular permeability and thus may deteriorate tissue damage. In order to apply safely the therapeutic angiogenesis for ischemic stroke treatment, elucidating precise mechanism of brain angiogenesis is mandatory. In the present article, we review previous reports which investigated molecular mechanisms of angiogenesis. Endothelial cell mitogens, enzymes that degrade surrounding extracellular matrix, and molecules implicated in endothelial cells migration are induced rapidly in the ischemic brain. Their possible neuroprotective or injury exacerbating effects are discussed. Because therapeutic potential of angiogenic factors application had gained much attention, we here extensively reviewed relevant previous reports. In the future however, there is a need to consider angiogenesis in relation with regenerative medicine, as angiogenic factors sometimes possess neuron producing property.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.