bioequivalence translate into therapeutic equivalence? When we look at the new guidance that the FDA has proposed, we fear that with the current criteria, this may not always be the case and that, as a result, there will be some patients who are at risk.
I'm going to give you an abstract of the study that we ran and then go through the details of the study, but basically, if you don't correct for endogenous levels of T4, then you cannot detect differences of 33 percent in dose. All the correction factors work actually quite well in terms of detecting 25 percent differences in dose, but they're unable to detect 12.5 percent differences.
Beyond that, we looked at some other factors and found TSH particularly good and promising for distinguishing very small differences in dose in bioequivalence studies.
Shown here are the results of our study. This is Study 417. It was a typical randomized, three-way crossover comparing doses of 600, 450 and 400 micrograms. The difference between 400 and 600 is 33 percent. All these doses came out of the same lot of Synthroid.
Going to the bottom, the FDA has proposed a