The US Food and Drug Administration (FDA) has stopped a large safety
study of the inhaled asthma drug salmeterol xinafoate (Serevent) after interim
results suggested an increased risk of life-threatening events in some patients.
Although 28 000 individuals had enrolled in the study, the researchers
agreed that continuing the trial would not yield clear results, because the
number of life-threatening events was too low to reach statistical significance.
However, a subgroup analysis showed that black volunteers experienced
a statistically significant heightened risk for life-threatening episodes.
The FDA emphasized that fewer than 1% of blacks enrolled in the study experienced
such events during the 28-week trial. Upon entering the study, black patients
tended to have more severe asthma, which may explain why those patients had
higher rates of serious adverse effects.
Vastag B. WebM&M. JAMA. 2003;289(7):833. doi:10.1001/jama.289.7.833-a