Increasing Participation of Women in Early Phase Clinical Trials Approved by the FDA

Background

Historically women were excluded from participation in phase 1 clinical trials. The goal of this study was to determine the participation of women and evaluate if participation has increased over time.

Methods

Clinical trial data submitted to the FDA for New Molecular Entities (NMEs) for adult, non-sex specific indications between January 2006 and December 2007 were reviewed. Electronic data available on phase 1 trial were evaluated for proposed indications, sex of participants, and doses tested. Therapeutic doses were obtained from the approved labeling.

Results

FDA approved 34 NMEs in 2006–2007. Data for 352 phase 1 trial of 30 NMEs were obtained. Data for 1 NME was not available electronically , 2 did not include new phase 1 data, and 1 provided only summary demographic data. All NMEs reviewed were for drugs used to treat conditions occurring in both men and women. Overall 120 (34.1%) trials had only male participants while 232 (65.9%) trials also enrolled female participants. 30.6% (3106/10,134) of participants were women. 149/352 (42.3%) of trials included safety and tolerability testing above the highest approved dose. In those trials, 32.5% (1628/5011) of the participants were women. An evaluation of trial start date illustrated the number of trials that enrolled women (p = 0.01) and the number of female participants (p < 0.001) has increased over time.

Conclusion

Females subjects have traditionally been underrepresented in phase 1 trials. The number trials enrolling women and the number of women participating in phase 1 trials has increased since 2001, however, women are still underrepresented.