2. 2, r e m o ve d refere nces t o c o h orts re m o ve d i n pr ot oc ol ver si o n 5. Clarifie d efficac y o ut p uts are f or d ose -e x pa nsi o n o nl y a n d acc or di n gl y re m o ve d refere nces t o I N R C w hic h is f or t he N B c o h ort e nr olle d i n d ose -fi n di n g o nl y . Secti o n 4.