Data-driven strategies for increasing patient diversity in Bristol Myers Squibb-sponsored US oncology clinical trials.

BACKGROUND/AIMS: Determining whether clinical trial findings are applicable to diverse, real-world patient populations can be challenging when the full demographic characteristics of enrolled patients are not consistently reported. Here, we present the results of a descriptive analysis of racial and ethnic demographic information for patients in Bristol Myers Squibb (BMS)-sponsored oncology trials in the United States (US) and describe factors associated with increased patient diversity. METHODS: BMS-sponsored oncology trials conducted at US sites with study enrollment dates between 1 January 2013 and 31 May 2021 were analyzed. Patient race/ethnicity information was self-reported in case report forms. As principal investigators (PIs) did not report their own race/ethnicity, a deep-learning algorithm (ethnicolr) was used to predict PI race/ethnicity. Trial sites were linked to counties to understand the role of county-level demographics. The impact of working with patient advocacy and community-based organizations to increase diversity in prostate cancer trials was analyzed. The magnitude of associations between patient diversity and PI diversity, US county demographics, and recruitment interventions in prostate cancer trials were assessed by bootstrapping. RESULTS: A total of 108 trials for solid tumors were analyzed, including 15,763 patients with race/ethnicity information and 834 unique PIs. Of the 15,763 patients, 13,968 (89%) self-reported as White, 956 (6%) Black, 466 (3%) Asian, and 373 (2%) Hispanic. Among 834 PIs, 607 (73%) were predicted to be White, 17 (2%) Black, 161 (19%) Asian, and 49 (6%) Hispanic. A positive concordance was observed between Hispanic patients and PIs (mean = 5.9%; 95% confidence interval (CI) = 2.4, 8.9), a less positive concordance between Black patients and PIs (mean = 1.0%; 95% CI = -2.7, 5.5), and no concordance between Asian patients and PIs. Geographic analyses showed that more non-White patients enrolled in study sites in counties with higher proportions of non-White residents (e.g. a county population that was 5%-30% Black had 7%-14% more Black patients enrolled in study sites). Following purposeful recruitment efforts in prostate cancer trials, 11% (95% CI = 7.7, 15.3) more Black men enrolled in prostate cancer trials. CONCLUSION: Most patients in these clinical trials were White. PI diversity, geographic diversity, and recruitment efforts were related to greater patient diversity. This report constitutes an essential step in benchmarking patient diversity in BMS US oncology trials and enables BMS to understand which initiatives may increase patient diversity. While complete reporting of patient characteristics such as race/ethnicity is critical, identifying diversity improvement tactics with the highest impact is essential. Strategies with the greatest concordance to clinical trial patient diversity should be implemented to make meaningful improvements to the diversity of clinical trial populations.

Acentrosomal spindles assemble from branching microtubule nucleation near chromosomes in Xenopus laevis egg extract.

Microtubules are generated at centrosomes, chromosomes, and within spindles during cell division. Whereas microtubule nucleation at the centrosome is well characterized, much remains unknown about where, when, and how microtubules are nucleated at chromosomes. To address these questions, we reconstitute microtubule nucleation from purified chromosomes in meiotic Xenopus egg extract and find that chromosomes alone can form spindles. We visualize microtubule nucleation near chromosomes using total internal reflection fluorescence microscopy to find that this occurs through branching microtubule nucleation. By inhibiting molecular motors, we find that the organization of the resultant polar branched networks is consistent with a theoretical model where the effectors for branching nucleation are released by chromosomes, forming a concentration gradient that spatially biases branching microtbule nucleation. In the presence of motors, these branched networks are ultimately organized into functional spindles, where the number of emergent spindle poles scales with the number of chromosomes and total chromatin area.

Confinement size determines the architecture of Ran-induced microtubule networks.

The organization of microtubules (MTs) is critical for cells during interphase and mitosis. During mitotic spindle assembly, MTs are made and organized around chromosomes in a process regulated by RanGTP. The role of RanGTP has been explored in Xenopus egg extracts, which are not limited by a cell membrane. Here, we investigated whether cell-sized confinements affect the assembly of RanGTP-induced MT networks in Xenopus egg extracts. We used microfluidics to encapsulate extracts within monodisperse extract-in-oil droplets. Importantly, we find that the architecture of Ran-induced MT networks depends on the droplet diameter and the Ran concentration, and differs from structures formed in bulk extracts. Our results highlight that both MT nucleation and physical confinement play critical roles in determining the spatial organization of the MT cytoskeleton.

Whole-brain calcium imaging with cellular resolution in freely behaving Caenorhabditis elegans.

The ability to acquire large-scale recordings of neuronal activity in awake and unrestrained animals is needed to provide new insights into how populations of neurons generate animal behavior. We present an instrument capable of recording intracellular calcium transients from the majority of neurons in the head of a freely behaving Caenorhabditis elegans with cellular resolution while simultaneously recording the animal's position, posture, and locomotion. This instrument provides whole-brain imaging with cellular resolution in an unrestrained and behaving animal. We use spinning-disk confocal microscopy to capture 3D volumetric fluorescent images of neurons expressing the calcium indicator GCaMP6s at 6 head-volumes/s. A suite of three cameras monitor neuronal fluorescence and the animal's position and orientation. Custom software tracks the 3D position of the animal's head in real time and two feedback loops adjust a motorized stage and objective to keep the animal's head within the field of view as the animal roams freely. We observe calcium transients from up to 77 neurons for over 4 min and correlate this activity with the animal's behavior. We characterize noise in the system due to animal motion and show that, across worms, multiple neurons show significant correlations with modes of behavior corresponding to forward, backward, and turning locomotion.

Does HIV VCT reduce risk behaviors? An observational study in Guatemala City.

OBJECTIVE: We examined the impact of HIV voluntary counseling and testing on self-reported behavioral risks three months after HIV testing. DESIGN: Cohort study comparing self-reported risk behaviors prior to and three months after HIV testing. SETTING: Clinica Familiar Luis Angel Garcia, an HIV specialty clinic located in a Guatemalan National Hospital. SUBJECTS, PARTICIPANTS: 144 people undergoing HIV testing were enrolled. 44 were HIV positive. 41 HIV positive and 49 HIV negative subjects returned for follow-up interviews. INTERVENTION: All subjects were tested and received voluntary counseling regarding HIV infection, transmission, prevention, and interpretation of HIV test results. MAIN OUTCOME MEASURE: The primary study outcome measure was change in self-reported risk behaviors three months after voluntary counseling and testing. RESULTS: Men were more likely than women to report a history of sexually transmitted diseases, more than 2 sexual partners, using alcohol with sex, and receiving money for sex; they were less likely to have a regular partner. 26% of men reported non-heterosexual orientation; no woman did. Alcohol was the primary drug of abuse in both men and women. At three month follow-up HIV positive subjects showed decreases in the average number of sexual partners, use of alcohol with sex, and episodes of unprotected sex. CONCLUSIONS: Voluntary counseling and testing resulted in changes in some self-reported risk behaviors, but only among HIV positive subjects. On nearly all measures men report riskier behavior than women. Alcohol is the most commonly used drug in this population and is often used with sex.