Glioblastoma recurrence after aggressive therapy typically occurs within six months, and patients inevitably succumb to their disease. Tumor recurrence is driven by a subpopulation of cancer stem cells in glioblastoma (glioblastoma stem-like cells, GSCs), which exhibit resistance to cytotoxic therapies, compared to their non-stem-cell counterparts. Here, we show that the Cox-2 and Wnt signaling pathways are aberrantly activated in GSCs and interact to maintain the cancer stem cell identity. Cox-2 stimulates GSC self-renewal and proliferation through prostaglandin E2 (PGE2), which in turn activates the Wnt signaling pathway. Wnt signaling underlies PGE2-induced GSC self-renewal and independently directs GSC self-renewal and proliferation. Inhibition of PGE2 enhances the effect of temozolomide on GSCs, but affords only a modest survival advantage in a xenograft model in the setting of COX-independent Wnt activation. Our findings uncover an aberrant positive feedback interaction between the Cox-2/PGE2 and Wnt pathways that mediates the stem-like state in glioblastoma.

ObjectivesTo analyse enrolment to interventional trials during the first wave of the COVID-19 pandemic in England and describe the barriers to successful recruitment in the circumstance of a further wave or future pandemics.DesignWe analysed registered interventional COVID-19 trial data and concurrently did a prospective observational study of hospitalised patients with COVID-19 who were being assessed for eligibility to one of the RECOVERY, C19-ACS or SIMPLE trials.SettingInterventional COVID-19 trial data were analysed from the clinicaltrials.gov and International Standard Randomized Controlled Trial Number databases on 12 July 2020. The patient cohort was taken from five centres in a respiratory National Institute for Health Research network. Population and modelling data were taken from published reports from the UK government and Medical Research Council Biostatistics Unit.Participants2082 consecutive admitted patients with laboratory-confirmed SARS-CoV-2 infection from 27 March 2020 were included.Main outcome measuresProportions enrolled, and reasons for exclusion from the aforementioned trials. Comparisons of trial recruitment targets with estimated feasible recruitment numbers.ResultsAnalysis of trial registration data for COVID-19 treatment studies enrolling in England showed that by 12 July 2020, 29 142 participants were needed. In the observational study, 430 (20.7%) proceeded to randomisation. 82 (3.9%) declined participation, 699 (33.6%) were excluded on clinical grounds, 363 (17.4%) were medically fit for discharge and 153 (7.3%) were receiving palliative care. With 111 037 people hospitalised with COVID-19 in England by 12 July 2020, we determine that 22 985 people were potentially suitable for trial enrolment. We estimate a UK hospitalisation rate of 2.38%, and that another 1.25 million infections would be required to meet recruitment targets of ongoing trials.ConclusionsFeasible recruitment rates, study design and proliferation of trials can limit the number, and size, that will successfully complete recruitment. We consider that fewer, more appropriately designed trials, prioritising cooperation between centres would maximise productivity in a further wave.

IMPORTANCEIn recent years, drug approvals have been based on fewer, smaller, and less rigorous pivotal trials. Less robust preapproval testing raises questions about the efficacy and clinical value of these drugs. OBJECTIVE To assess the regulatory context, pivotal design characteristics, and postmarket requirements (PMRs) and postmarket commitments (PMCs) of novel 2020 drug approvals to characterize the state of evidence at the time of approval. DESIGN, SETTING, AND PARTICIPANTS This cohort study identified novel drugs approved by the US Food and Drug Administration's (FDA) Center for Drug Evaluation and Research in 2020. The Drugs@FDA database was used to extract key characteristics of each drug's pivotal trials. Drug approval packages provided regulatory information. The prevalence of key trial design features was compared between oncology and nononcology drugs. EXPOSURES Drug names, date of approval, indication on labeling, and clinical and regulatory details. MAIN OUTCOMES AND MEASURES Number of pivotal trials, pivotal trial design (randomization, masking, groups), trial comparator, trial hypothesis, trial end points, results, number and type of expedited pathway designations, and number and type of PMRs and PMCs. RESULTSThe 49 novel therapeutics approved in 2020 were supported by 75 pivotal trials. More than half of drugs (28 [57.1%]) were supported by a single pivotal trial. Trial sizes ranged from 19 to 2230 participants. More than three-fourths of trials (57 [76.0%]) had a randomization component, and nearly two-thirds (46 [61.3%]) were double-masked. Most used a superiority approach. Roughly half (39 [52.0%]) compared the novel therapeutic with a placebo or vehicle control; 13 (17.3%), an active control; 2 (2.7%), both a placebo and active control; and 21 (28.0%), a historical, external, or other control. Nearly half of pivotal trials (34 [45.3%]) used a surrogate measure as a primary end point. Pivotal trials supporting oncology approvals were much more likely to have historical controls than nononcology approvals (13 of 18 [72.2%] vs 8 of 57 [14.0%]; P < .001) and to use at least 1 surrogate measure as a primary end point (17 [94.4%] vs 17 [29.8%]; P < .001). Forty drugs had at least 1 PMR or PMC, accounting for 178 PMRs and PMCs across the cohort. CONCLUSIONS AND RELEVANCEThese findings suggest that the increased flexibility in the characteristics of acceptable preapproval evidence can be partially explained by the increase in trials of drugs for rare and other serious conditions that require flexible testing strategies as well as the associated regulatory changes that have accumulated over time. The FDA and consumers may (continued) Key Points Question What were the key design characteristics of the pivotal trials supporting novel drugs approved by the US Food and Drug Administration (FDA) in 2020? Findings This cohort study of 49 drugs approved by the FDA in 2020 found that they were supported by 75 pivotal trials, of which nearly two-thirds were double-masked, more than threefourths had a randomiz...

In 2006, the US Food and Drug Administration (FDA) launched the Unapproved Drug Initiative (UDI) to document supporting data for several thousand drugs that had remained on the US market continually since before the agency began reviewing safety and effectiveness in 1938. 1 As an incentive, the FDA offered market exclusivity to the first manufacturer to receive approval of a legacy drug.In the short term, these market exclusivity periods drove up drug prices, most notably for the antigout drug colchicine. 2,3 In November 2020, the FDA announced that the UDI program was ending, citing concerns that the program raised prices without generating new clinical data for most drugs. 4 To assess the long-term effects of the UDI, we evaluated market exclusivity characteristics under the UDI program and how competition and prices changed 5 years after drug approval.