WHO Senior Adviser Calls for Systematic Reviews to Address Clinical Trial Diversity Gap
Key Insights
WHO data reveals critical underrepresentation in clinical trials, with less than 5% including pregnant women and only 13% including children, highlighting a significant evidence gap in medical research.
WHO senior adviser Vasee Moorthy emphasizes the disconnect between trial populations and intended beneficiaries, calling for systematic reviews to improve population representation in clinical studies.
Recent developments show promise, with Bavarian Nordic initiating a Phase III trial to evaluate mpox (search) vaccine in pregnant women, addressing a crucial gap in vaccine accessibility.
The World Health Organization (WHO) is pushing for major changes in clinical trial practices to address the significant underrepresentation of key population groups, according to WHO senior adviser Vasee Moorthy at the recent Outsourcing in Clinical Trials and Clinical Trial Supply East Asia conference in Seoul.
Current data paints a concerning picture of exclusion in clinical research. WHO statistics from 2022 reveal that less than 5% of clinical trials included pregnant women, while only 13% included children. This systematic exclusion has resulted in lower quality evidence and reduced access to potentially beneficial interventions for these populations.
"We often see that the populations that are most in need of interventions are not included in clinical trials," Moorthy emphasized during the conference. "There is a disconnect between the populations in trials and the populations that interventions seek to benefit, including older people, pregnant women, and children."
Impact on Healthcare Delivery
The limited representation in clinical trials has far-reaching consequences for healthcare delivery. When populations are excluded from trials, healthcare providers often take an overly cautious approach to treatment, potentially denying effective therapies to those who might benefit most. This was recently highlighted in Australia, where mothers and babies faced risks due to critical shortages of medicines considered safe during pregnancy.
Current data from GlobalData (search) shows that while 36% of clinical trials initiated in 2024 explicitly exclude pregnant women, only 4% include them in their inclusion criteria, highlighting the persistent nature of this problem.
WHO's New Guidance and Reform Initiatives
In response to these challenges, WHO has introduced new guidance for best practices in clinical trials. The comprehensive document outlines recommendations for various stakeholders, including:
- Sponsors and CROs
- Clinical investigators
- Regulatory agencies
The guidance aims to improve trial design, conduct, and oversight across countries of all income levels, with a particular focus on increasing population representation.
Signs of Progress
Despite the challenges, there are encouraging developments in the field. Bavarian Nordic has taken a significant step forward by initiating a Phase III trial to evaluate its mpox (search) vaccine in pregnant women. This is particularly important as pregnant women have been disproportionately affected by the ongoing mpox outbreak in Africa, with limited access to vaccination options.
"There needs to be a systematic process to look at why certain populations are excluded [from trials], or why to include them later in the trial," Moorthy stated, emphasizing the need for a structured approach to addressing these disparities.
Historical Context and Current Challenges
The systematic exclusion of certain populations, particularly pregnant women, has deep historical roots. The thalidomide tragedy of the 1950s and 1960s created lasting hesitancy in including pregnant women in clinical research. While female participation in trials has gradually improved, pregnant women continue to be significantly underrepresented.
Moving forward, the medical research community faces the challenge of balancing safety concerns with the need for comprehensive evidence across all population groups. The WHO's new guidance represents a crucial step toward achieving this balance and ensuring that clinical trials better serve the diverse populations they aim to benefit.