>> The analyst, William Sargent of Banc of America, said Human Genome Sciences said the efficacy of its lower-dose treatments has been above 90 percent, which should be enough to file for regulatory approval. <<
Either Sargent or the Wash Post botched the story (probably the latter).
What HGS actually said on the CC is that the statistical power for hitting the primary non-inferiority endpoint on the lower dose is 90%. This has nothing to do with “90% efficacy,” the phrase used in the article.
“The efficient-market hypothesis may be the foremost piece of B.S. ever promulgated in any area of human knowledge!”