WASHINGTON, D.C.—The overall inclusion of women in cardiovascular disease (CVD) drug trials is comparable to the overall female CVD population; however, women are largely underrepresented in Phase 1 trials. Despite this improvement, minorities are still grossly underrepresented, particularly in the acute coronary syndrome drug trials.

This FDA study was presented as a scientific poster at the Cardiovascular Research Technologies (CRT) annual meeting held Feb. 23-26.

Historically, women and minorities have been under-represented in clinical trials of drugs to treat CVD, according to Noha Eshera and colleagues from the FDA in Silver Spring, Md. “To accurately assess the safety and efficacy of CVD drugs, the FDA has made a conscious effort to ensure adequate representation of women and minorities in clinical drug trials through guidance documents and regulations,” they wrote.

With this study, the agency researchers sought to assess the participation of women and racial/ethnic minorities in FDA-reviewed CVD drug trials that were included in new drug applications (NDAs) approved between 2010 and 2011. They assessed the sex and race/ethnicity of subjects in all CVD drug trials submitted to FDA in support of NDAs approved between January 2010 and December 2011 from final clinical study reports. The reports were accessed via internal FDA databases.

Four drugs (one per NDA) indicated for hypertension, acute coronary syndrome, nonvalvular atrial fibrillation and deep vein thrombosis/pulmonary embolism (DVT/PE) after joint replacement surgery were approved during the period studied. A total of 231 clinical trials classified as Phase 1, 2 or 3 studies were submitted to the NDAs. There were 107,156 subjects included in these studies.

The demographic analysis showed that the mean participation of women in these trials was 41 percent and the majority of the trial subjects were Caucasians (79 percent). When analyzed by the phase of the trials, mean female participation was 21 percent, 43 percent and 42 percent for Phase 1, 2 and 3 respectively.

Noting the disparity in early-stage trials, Noha et al pointed out that much of the pharmacokinetics and pharmacodynamics are evaluated during Phase 1 trials.

While the outlook is clearly improving for the inclusion of women, the inclusion of minorities is still very low. In the overall trial of 107,156 patients, 79 percent of trial subjects were Caucasian. In addition, 8.5 percent were Asian, 2.4 percent were black, 2.1 percent were "other," 1.8 percent were Hispanic and 2 percent were unknown.

In an example of the greatest disparity, the acute coronary syndrome drug trials (21,127 patients), had a population where 90 percent were Caucasian, 6.3 percent were Asian, 3.1 were Hispanic and 2 percent were black. Also, only 28 percent of this population was female.

In the hypertension drug trials (10,558 patients), 44 percent were female and 68 percent were Caucasian. Looking at the other races/ethnicities in these trials, 12 percent were black, 11 percent were Hispanic, 10 percent were Asian and 9.7 percent were "other."

In the atrial fibrillation drug trials (33,662 patients), 41 percent were female and 78 percent were Caucasian. These trials included the largest population of blacks (6.8 percent) compared with the other disease states, but no Hispanics. Also, 3.2 percent of the population was Asian, 1.4 percent was unknown and 0.5 percent was "other."

Finally, in the drug trials looking at DVT/PE (41,809 participants), 47 percent were female and 77 percent were Caucasian. Looking at the other populations, 13 percent were Asian, 3.9 percent were unknown, 1.9 percent were Hispanic, 1.7 percent were "other" and 1.5 percent were black.