Good point re the different prevalence of GT1a vs GT1b in different countries; however, the percentages are not unduly lopsided. Among all GT1 patients, if one assumes 2/3 of treated patients will be GT1a in the US and 2/3 of treated patients will be GT1b in Japan and the EU, that’s probably close enough for modeling purposes.
“The efficient-market hypothesis may be the foremost piece of B.S. ever promulgated in any area of human knowledge!”