My Girl likes Pink and My Boy Likes Blue: Study of Gender Differences in Clinical Trials
[Posted on: Thursday, October 15, 2015]
I have always wondered why my daughter and son have different preferences even though we have consciously tried to keep our home gender neutral. Both share similar toys, wear similar clothes, eat similar food and are provided similar nurture. Still my girl prefers pink clothes and stuffed animals while my son loves blue and cars. Male and females vary not just in behavioral patterns but their susceptibility to diseases and responses to medication.
In the early years of clinical research, FDA practically banned participation of women in clinical trials. Hence all new drugs developed were tested only in male subjects and women were prescribed drugs off-label. Most limitations of drugs in treating women compared to men for the same indication were only discovered much later. Most women’s health issues remained neglected. A GAO report in 1992 shed light on this discrepancy in gender differences in drug testing followed by an FDA notice in 1993 to include gender differences in clinical trials, effectively requiring drug companies to include women in clinical trials.
In the last 20 years, great progress has been made in understanding how drugs and diseases interact differently in men and women. We know that Alzheimer’s affects about twice the number or women compared to men, women are more prone to nicotine addiction, lung cancer, depression, anorexia and pain. Men are more prone to autism, ADHD, while both men and women show equal predisposition to bipolar disorder and schizophrenia. A recent review of literature shows that the biggest differences in disease occurrence and response to drugs between men and women occur in neuropsychiatric disorders. A study by GAO in 2001 found that most drugs withdrawn from market for safety reasons had greater risk in women.
Several studies by FDA to encourage participation of women in clinical trials have mixed success with two-thirds of clinical trial participants still being male subjects. In a guidance document released last year, FDA specifically require medical device trials to include female subjects and provide statistical data for differences between male and female subjects. We have come a long way from early 1990s but a lot more needs to be done. Recently discussion around the female Viagra approval showed that the public is ready to robustly support women health issues not traditionally addressed by the industry.
Expert Opinion: Mukesh Kumar
VP, RA, Amarex Clinical Research