Systematic Review of Gender Bias in the Clinical Trials of New Long-Acting Antipsychotic Drugs

First episode psychoses in people over-35 years old: uncovering potential actionable targets for early intervention services

The traditional youth-oriented design of Early Intervention Services (EIS) may lead to the exclusion of patients who have their psychotic onset later in life. A retrospective study was conducted to compare first-episode psychosis (FEP) patients who accessed treatment when aged ≤ 35 years with those ≥36+. A total of 854 patients were identified among 46,222 individuals who had access to community psychiatric services from 1991 to 2021. FEP were aged 18-65, received care between 2012 and 2021 and had a diagnosis of affective or non-affective FEP. Two groups were identified (FEP diagnosed at age ≤ 35 vs ≥ 36) and compared for sociodemographic and clinical characteristics. Most patients were diagnosed when aged ≥ 36+ (61.8%). Compared to the ≤ 35 group, older patients were more likely to be women, married and diagnosed with affective psychosis, and they were less frequently hospitalized. Long-acting injectables antipsychotics (LAI) were less frequently prescribed in the ≥ 36+ group, whereas antidepressants were more frequently prescribed compared to those aged ≤ 35. In both age groups, women were less frequently prescribed LAIs compared to men. These findings highlight the need to reorient EIS to accommodate the needs of older FEP, especially women.

First generation antipsychotic-associated serious adverse events in women: a retrospective analysis of a pharmacovigilance database

BACKGROUND

Women have been under-represented in trials of antipsychotic medications.

AIM

Our primary objective was to evaluate five adverse events (AE) associated with first-generation antipsychotics (FGAs) among women relative to men through an analysis of the FDA Adverse Event Reporting System (FAERS).

METHOD

We queried 24.6 million AE reports from 2000 to 2023 involving FGAs. The study cohort consisted of chlorpromazine (n = 3317), fluphenazine (n = 1124), haloperidol (n = 16,709), loxapine (n = 3151), perphenazine (n = 816), thioridazine (n = 665), thiothixene (n = 244), and trifluoperazine (n = 360). Cases of neuroleptic malignant syndrome (NMS), tardive dyskinesia (TD), Torsades de Pointes (TdP), agranulocytosis (AG), and cerebrovascular adverse events (CVAE) were identified. Reporting odds ratios (ROR) and associated 95% confidence intervals (CI) were calculated with logistic regression for each AE among women relative to men.

RESULTS

A total of 2,857 serious AEs were evaluated in the study cohort (NMS = 1810, TD = 434, TdP = 260, AG = 149, CVAE = 204). The ROR for women compared to men was 0.79 (95% CI, 0.71-0.87) for NMS, 0.83 (0.68-1.01) for TD, 1.21 (0.94-1.53) for TdP, 0.71 (0.51-0.98) for AG, and 0.91 (0.68-1.19) for CVAE. A secondary analysis revealed a higher odds in women compared to men of hospitalization associated with reports of TD (ROR = 1.95, 1.29-2.94) and death associated with reports of AG (ROR = 2.46, 1.15-5.24). A subgroup analysis of haloperidol revealed an ROR = 1.67 (1.26-2.21) for women relative to men for TdP.

CONCLUSION

The subgroup analysis of haloperidol AEs revealed a significantly higher reporting odds ratio for TdP. Additionally, the secondary study findings suggest that women were more vulnerable to worse outcomes associated with certain AEs of FGAs.

Sex differences in schizophrenia-spectrum diagnoses: results from a 30-year health record registry

This study investigated sociodemographic and clinical differences between the sexes in individuals affected by schizophrenia-spectrum disorders (SSD) who accessed outpatient mental health services. Within a retrospective cohort of 45,361 outpatients receiving care in Ferrara (Italy) from 1991 to 2021, those with a SSD diagnosis were compared between the sexes for sociodemographic and clinical characteristics before and after the index date (when the ICD-9: 295.*diagnosis was first recorded) to assess early trajectory, age and type of diagnosis, and severity of illness indicated by medication use, hospitalization, and duration of psychiatric care. Predictors of discharge were also investigated. Among 2439 patients, 1191 were women (48.8%). Compared to men, women were significantly older at first visit (43.7 vs. 36.8 years) and at index date (47.8 vs. 40.6) with peak frequency at age 48 (vs. 30). The most frequent last diagnosis recorded before the index date was delusional disorder (27.7%) or personality disorder (24.3%) in men and depression (24%) and delusional disorder (30.1%) in women. After the index date, long-acting antipsychotics and clozapine were more frequently prescribed to men (46.5% vs. 36.3%; 13.2% vs. 9.4%, p < 0.05) and mood stabilizers and antidepressants to women (24.3% vs. 21.1%; 50.1% vs. 35.5%; p < 0.05). Women had fewer involuntary admissions (10.1% vs. 13.6%) and were more likely to be discharged as the time under care increased (p = 0.009). After adjusting for covariates, sex was not a significant predictor of discharge. Our study confirmed that sex differences exist in clinical and sociodemographic characteristics of outpatients with SSD and that gender considerations might influence the rapidity of diagnosis and medications prescribed. These findings highlight the need to implement a women-tailored approach in specialist care programs for psychoses.

Systematic review of gender bias in clinical trials of monoclonal antibodies for the treatment of multiple sclerosis

INTRODUCTION

This article analyses the presence of gender bias in clinical trials of monoclonal antibodies used to treat multiple sclerosis.

MATERIAL AND METHODS

We performed a systematic review of controlled clinical trials of 4 monoclonal antibodies used to treat multiple sclerosis (natalizumab, rituximab, alemtuzumab, and ocrelizumab). We searched the PubMed/MEDLINE database for articles published in English before March 2020. The study was conducted in accordance with the relevant international recommendations.

RESULTS

The search identified 89 articles, 55 of which met the inclusion criteria. Of all patients included in these trials, 64.6% were women. The lead authors of 10 of the studies were women. Fifteen of the 55 studies included a sex-based analysis of the primary endpoint. Only 8 articles discussed the results separately for men and for women.

CONCLUSIONS

The clinical trials of these 4 monoclonal antibodies present a significant gender bias. In most cases, the primary and secondary endpoints are not analyzed according to patient sex, despite the fact that international recommendations include this as a minimum requirement for ensuring scientific validity and obtaining appropriate results for extrapolation to the wider population.

An NIMH Workshop on Non-Affective Psychosis in Midlife and Beyond: Research Agenda on Phenomenology, Clinical Trajectories, Underlying Mechanisms, and Intervention Targets

We present a review of the state of the research in the phenomenology, clinical trajectories, biological mechanisms, aging biomarkers, and treatments for middle-aged and older people with schizophrenia (PwS) discussed at the NIMH sponsored workshop "Non-affective Psychosis in Midlife and Beyond." The growing population of PwS has specific clinical needs that require tailored and mechanistically derived interventions. Differentiating between the effects of aging and disease progression is a key challenge of studying older PwS. This review of the workshop highlights the recent findings in this understudied clinical population and the critical gaps in knowledge and consensus for research priorities. This review showcases the major challenges and opportunities for research to advance clinical care for this growing and understudied population.

Sex differences in antipsychotic-related triglyceride levels are associated with metabolic hormone differences in patients with severe mental disorders

BACKGROUND

Adverse effects of antipsychotics (AP) contribute to cardiovascular disease (CVD) risk in patients with severe mental disorders (SMD). We investigated sex differences in AP-related CVD risk factors and the role of metabolic hormones.

METHODS

Patients with SMD (N = 1791) receiving AP with different CVD risk were recruited and grouped into olanzapine and/or clozapine (N = 532), other APs (N = 744) or no use of APs (N = 515). Associations between CVD risk factor (total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), body mass index (BMI), glucose, blood pressure), sex and AP groups were tested in multiple linear regression with interactions, controlling for diagnostic group, lifestyle factors, polypharmacy, age and ethnicity. Next, we tested associations between sex differences in AP-related CVD risk factors and metabolic regulatory hormones.

RESULTS

AP groups and male sex were significantly associated with higher levels of LDL-C, TG and BMI, and lower levels of HDL-C. Significant interaction between AP groups and sex were found for TG (p = 0.017), with larger increase in males. Serum adiponectin, insulin, cortisol, leptin, testosterone, free thyroxine and thyroid-stimulating hormone (TSH) were associated with TG levels (all p ≤ 0.001), and a significant interaction with sex for insulin (p = 0.005), cortisol (p = 0.016), leptin (p < 0.001) and TSH (p = 0.001).

CONCLUSIONS

We found more severe AP-related CVD risk factors in male patients with SMD. The male-dependent increase in TG levels was associated with leptin, insulin, cortisol and TSH levels. Clinicians treating patients with SMD should be aware of increased vulnerability for AP-related lipid abnormalities in males.

Antipsychotic medication for women with schizophrenia spectrum disorders

There are significant differences between men and women in the efficacy and tolerability of antipsychotic drugs. Here, we provide a comprehensive overview of what is currently known about the pharmacokinetics and pharmacodynamics of antipsychotics in women with schizophrenia spectrum disorders (SSDs) and translate these insights into considerations for clinical practice. Slower drug absorption, metabolism and excretion in women all lead to higher plasma levels, which increase the risk for side-effects. Moreover, women reach higher dopamine receptor occupancy compared to men at similar serum levels, since oestrogens increase dopamine sensitivity. As current treatment guidelines are based on studies predominantly conducted in men, women are likely to be overmedicated by default. The risk of overmedicating generally increases when sex hormone levels are high (e.g. during ovulation and gestation), whereas higher doses may be required during low-hormonal phases (e.g. during menstruation and menopause). For premenopausal women, with the exceptions of quetiapine and lurasidone, doses of antipsychotics should be lower with largest adjustments required for olanzapine. Clinicians should be wary of side-effects that are particularly harmful in women, such as hyperprolactinaemia which can cause oestrogen deficiency and metabolic symptoms that may cause cardiovascular diseases. Given the protective effects of oestrogens on the course of SSD, oestrogen replacement therapy should be considered for postmenopausal patients, who are more vulnerable to side-effects and yet require higher dosages of most antipsychotics to reach similar efficacy. In conclusion, there is a need for tailored, female-specific prescription guidelines, which take into account adjustments required across different phases of life.

Gender bias in clinical trials of biological agents for severe asthma: A systematic review

Asthma is one of the most common chronic diseases characterized by sex disparities. Gender bias is a well-documented issue detected in the design of published clinical trials (CTs). International guidelines encourage researchers to analyze clinical data by sex, gender, or both where appropriate. The objective of this work was to evaluate gender bias in the published CTs of biological agents for the treatment of severe asthma. A systematic review of randomized controlled CTs of the biological agents (omalizumab, benralizumab, reslizumab, mepolizumab or dupilumab) for the treatment of severe asthma was conducted. The literature search was performed using PubMed and EMBASE without language restrictions. This study followed the corresponding international recommendations. We identified a total of 426 articles, of which 37 were finally included. Women represented 60.4% of patients included. The mean percentage of women in these trials was 59.9%, ranged from 40.8% to 76.7%. The separate analysis by sex of the main variable was only performed in 5 of the 37 publications included, and none of the trials analyzed secondary variables by sex. Only 1 of the articles discussed the results separately by sex. No study included the concept of gender in the text or analyzed the results separately by gender. The proportion of women included in CTs was higher compared to publications of other disciplines, where women were under-represented. The analysis of the main and secondary variables by sex or gender, even the discussion separately by sex, was insufficient. This gives rise to potential gender bias in these CTs.

Gender dimorphic effect of dopamine D2 and muscarinic cholinergic receptors on memory retrieval

Episodic memory retrieval is fundamental for daily activities of humans and animals. Muscarinic cholinergic signaling is important for memory functioning and shows gender-dependent response in episodic memory retrieval. Dopamine D2 receptors influence memory formation and retrieval by influencing cholinergic signaling in the brain. This study aimed to determine the gender-dependent effects of D2 and muscarinic activity on memory retrieval. Male and female mice were trained for Morris water maze test and contextual fear conditioning. Memory retrieval was assessed following sub-chronic treatment (for 5 days) with D2 antagonist (risperidone 2.5 mg/kg) alone or in combination with scopolamine (1 mg/kg) or donepezil (1 mg/kg). Open field test was performed prior to the retrieval test to evaluate effects of risperidone treatment on locomotor activity and exploratory behavior. Risperidone co-treatment with donepezil impaired spatial memory retrieval in males only. Muscarinic and D2 simultaneous antagonism tend to impair fear retrieval in males but significantly enhanced retrieval of fear memories in female mice. These results suggest that D2 signaling influence muscarinic receptor activity during memory retrieval in gender-dependent manner.

Publication bias is the consequence of a lack of diversity, equity, and inclusion

Publication bias has been shown to exist in research across medical and surgical specialties. Bias can occur at any stage of the publication process and can be related to race, ethnicity, age, religion, sex, gender, or sexual orientation. Although some improvements have been made toward addressing this issue, bias still spans the publication process from authors and peer reviewers, to editorial board members and editors, with poor inclusion of women and underrepresented minorities throughout. The result of bias remaining unchecked is the publication of research that leaves out certain groups, is not applicable to all people, and can result in harm to some populations. We have highlighted the current landscape of publication bias and strived to demonstrate the importance of addressing it. We have also provided solutions for reducing bias at multiple stages throughout the publication process. Increasing diversity, equity, and inclusion throughout all aspects of the publication process, requiring diversity, equity, and inclusion statements in reports, and providing specific education and guidelines will ensure the identification and eradication of publication bias. By following these measures, we hope that publication bias will be eliminated, which will reduce further harm to certain populations and promote better, more effective research pertinent to all people.

Systematic review of gender bias in vortioxetine clinical trials

This paper evaluates gender bias in the published clinical trials of Vortioxetine. We conducted a systematic review of controlled clinical trials of Vortioxetine for the treatment of depression. The literature search was performed using MEDLINE and following the corresponding international recommendations. We identified 42 articles, of which 23 were included. The proportion of women ranged from 47%-75% and the percentage of women included in the 10,404 total patients sample was 65%. The separate analysis of the main variable between the subpopulations of men and women was only carried out in 3/23 publications included. In contrast, 6/23 trials analyzed secondary variables separated by sex. No trials discussed the results separately by sex. The proportion of women included was slightly higher than that in clinical trials of other antidepressants. However, the analysis of the main result or secondary variables by sex, as well as discussing the results separately by sex, are scarce. This gives rise to gender bias in these works.

Sex Selection Bias in Schizophrenia Antipsychotic Trials—An Update Systematic Review

The lack of female participation in antipsychotic trials for schizophrenia poses an important issue regarding its applicability, with direct and real-life repercussions to clinical practice. Here, our aim is to systematically review the sampling sex bias among randomized clinical trials (RCTs) of second-generation antipsychotics—namely risperidone, olanzapine, quetiapine, ziprasidone, and aripiprazole—as an update to a previous 2005 review. We searched MEDLINE and the Cochrane database for studies published through 7 September 2020 that assessed adult samples of at least 50 subjects with a diagnosis of schizophrenia, schizophrenia spectrum disorder, or broad psychosis, in order to investigate the percentage of women recruited and associated factors. Our review included 148 RCTs, published from 1993 to 2020, encompassing 43,961 subjects. Overall, the mean proportion of women was 34%, but only 17 trials included 50% or more females. Younger samples, studies conducted in North America, pharmaceutical funding and presence of specific exclusion criteria for women (i.e., pregnancy, breast-feeding or lack of reliable contraceptive) were associated with a lower prevalence of women in the trials. Considering the possible different effects of antipsychotics in both sexes, and our lack of knowledge on the subject due to sampling bias, it is imperative to expand actions aimed at bridging this gap.

Systematic review of gender bias in clinical trials of monoclonal antibodies for the treatment of multiple sclerosis

INTRODUCTION

This article analyses the presence of gender bias in clinical trials of monoclonal antibodies used to treat multiple sclerosis.

MATERIAL AND METHODS

We performed a systematic review of controlled clinical trials of 4 monoclonal antibodies used to treat multiple sclerosis (natalizumab, rituximab, alemtuzumab, and ocrelizumab). We searched the PubMed/MEDLINE database for articles published in English before March 2020. The study was conducted in accordance with the relevant international recommendations.

RESULTS

The search identified 89 articles, 55 of which met the inclusion criteria. Of all patients included in these trials, 64.6% were women. The lead authors of 10 of the studies were women. Fifteen of the 55 studies included a sex-based analysis of the primary endpoint. Only 8 articles discussed the results separately for men and for women.

CONCLUSIONS

The clinical trials of these 4 monoclonal antibodies present a significant gender bias. In most cases, the primary and secondary endpoints are not analyzed according to patient sex, despite the fact that international recommendations include this as a minimum requirement for ensuring scientific validity and obtaining appropriate results for extrapolation to the wider population.