Gender Bias in Clinical Trial Enrollment: Female Authorship Matters.

BACKGROUND: Despite initiatives to promote equal enrollment of human subjects in clinical trials, females continue to be underrepresented. The goal of this work is to determine if female enrollment in human clinical trials published in 3 high-impact journals from 2015 to 2019 is correlated with gender of first and/or senior authors. METHODS: Clinical trials published in the Journal of the American Medical Association (JAMA), The Lancet, and the New England Journal of Medicine (NEJM) from January 1, 2015, to December 31, 2019, were reviewed. Trials were excluded for ongoing enrollment, sex-specific disease research, or author name without gender assignment. One-sample χ2 pairwise comparisons and two-tailed proportion tests on the proportion of females between gender author pairings were done overall and for each subset analysis. RESULTS: In total, 1,427 articles enrolled a total of 2,104,509 females and 2,616,981 males (44.6% vs. 55.4%, P ≤ 0.0001) in clinical trials. Overall, more females were enrolled if both first and senior authors were female (51.7% vs. 48.3%, P ≤ 0.0001). Proportion of females enrolled decreased with the following first and senior author pairings: female-male (48.9%), male-female (48.6%), and male-male (40.5%, P ≤ 0.0001 compared to female-female authorship). Greater female enrollment in clinical trials with female-female compared to male-male authorship persisted in subset analyses by funding source, phase, randomization for study participants, drug and/or device trial, and geographic location. Female enrollment was higher in 3 surgical specialties: neurosurgery (all authors: 52%, P ≤ 0.01), ophthalmology (all authors: 53.6%, P ≤ 0.0001), and surgery (all authors: 54.4%, P ≤ 0.0001). The majority of surgical specialties did not publish trials with female-female authorship but when stratifying by author gender pairing, surgical oncology had the highest female enrollment with female-female authorship (98.4%, P ≤ 0.0001). CONCLUSIONS: Female authorship of clinical trial publications, specifically having both first and senior authors as female, was correlated with higher female enrollment in clinical trials when compared to male authorship and endured with multiple subset analyses.

The Persistence of Sex Bias in High-Impact Clinical Research.

INTRODUCTION: Sex bias is present in clinical research resulting in disparities in the treatment of women. Our objective was to identify the prevalence of sex inclusiveness of participants in human clinical trials after the passage of National Institutes of Health (NIH) and United States Congress policies in 2015 and 2016 to increase female enrollment in clinical research. METHODS: We performed an observational analysis of data from registered clinical trials published in three high-impact biomedical journals from January 1, 2015 to December 31, 2019. RESULTS: One thousand four hundred and forty two manuscripts with 4,765,783 human subjects were included for analysis. Significantly more males (56%) than females (44%) were included in all three journals (P < 0.0001). Sex matching ≥ 80% was found in 24.6% of publications. Industry funded 43.7% of all studies enrolling significantly more males than females (60.8% versus 39.2%, P < 0.0001). NIH funded 10.2% of studies enrolling significantly more females than males (52.7% versus 47.3%, P < 0.0001). North America and Europe contributed 82.6% of the studies with each enrolling significantly more males than females (P < 0.0001). The United States was the country contributing the most studies (36.1%), enrolling significantly more males than females (55.5% versus 45.5%, P < 0.0001). Cardiovascular disease was the subject area of the most manuscripts among medical specialties (19%), enrolling significantly more males than females (64.9% versus 35.1%, P < 0.0001). Studies analyzed by clinical trial phase, type, trial, and allocation enrolled significantly more males than females (P < 0.0001). CONCLUSIONS: Sex bias remains prevalent in human clinical research trials. Improvements have been made in NIH-funded clinical trials; however, this constitutes a small percentage of overall studies.

Associations of microbiota and toll-like receptor signaling pathway in esophageal adenocarcinoma.

BACKGROUND: Toll-like receptors (TLRs) recognize known molecules from microbes and have an established role in tumorigenesis. Using a rat model of esophageal adenocarcinoma, and human clinical samples, we investigated genes central to TLR-mediated signal transduction and characterized the esophageal microbiome across the spectrum of esophageal adenocarcinoma carcinogenesis. METHODS: We surgically induced bile/acid reflux in rats and their esophagi were harvested at 40 weeks post-surgery. Tissue samples from the model were selected for gene expression profiling. Additionally, for rat and human samples microbiome analysis was performed using PCR-ESI-MS-TOF technology with validation by fluorescence in situ hybridization. RESULTS: Gene expression results in the rat model indicated a significant upregulation of TLRs 1-3, 6, 7 and 9 in EAC compared to normal epithelium. PCR-ESI-MS-TOF analysis revealed a prevalence of Escherichia coli in Barrett's esophagus (60%) and esophageal adenocarcinoma (100%), which was validated by fluorescence in situ hybridization. In the human clinical samples, Streptococcus pneumonia was detected in high abundance in gastroesophageal reflux disease and Barrett's esophagus (50-70%) in comparison to tumor adjacent normal epithelium, dysplasia, and esophageal adenocarcinoma (20-30%). E. coli was detected in the Barrett's esophagus and esophageal adenocarcinoma groups but was absent in the tumor adjacent normal epithelium, dysplasia, and the gastroesophageal reflux disease groups. CONCLUSIONS: We demonstrated an association between the TLR signaling pathway and E. coli hinting towards possible early molecular changes being mediated by microbes in the rat model of esophageal adenocarcinoma carcinogenesis. Studies on human clinical samples also corroborate results to some extent; however, a study with larger sample size is needed to further explore this association.

Systemic peptide amphiphile nanofiber delivery following subcutaneous injection.

Peptide amphiphile (PA) nanofibers have been shown to target and deliver drugs when administered via an intravenous (IV) injection. Subcutaneous administration can broaden the applicability of PA nanofibers in the medical field. The ability of PA nanofibers to be absorbed into systemic circulation after subcutaneous administration was investigated. Four PA molecules with different amino acid sequences were designed to understand the effect of nanofiber cohesion and charge on uptake. Solution small-angle X-ray scattering confirmed nanostructure morphology and provided characteristic lengths for co-assemblies. Circular dichroism and solution wide-angle X-ray scattering confirmed PA secondary structure and molecular order. PAs were co-assembled in a 95 %:5 % molar ratio of unlabeled PA to fluorescently labeled PA. Male and female Sprague Dawley rats were injected in the nape of the neck with PA co-assemblies. In vivo normalized abdominal fluorescence was measured 1-72 h after injection. PA nanofibers with a negative charge and low internal order showed the highest amount of systemic absorption at 1, 6, and 24 h. At 24 h after injection, white blood cell count decreased and glucose was elevated. Glucose began to decrease at 48 h. These data indicate that PA nanofibers can be absorbed into the systemic circulation after subcutaneous injection.