East Germany has a lower population than West Germany so this doesn’t fully translate to a 50-50 split. I think overall national polls put the AfD at 27%, ahead of the CDU which is at 24%. SPD is now in a distant third place. The trend over the past years has been in favor of the AfD and further growth is to be expected. This growth will come at the expense of the CDU more than any of the other parties, as it is CDU voters and non-voters who are most likely to switch over to the AfD. The CDU will then probably enter into coalition with the AfD when they can no longer form a government otherwise, unless the SPD somehow manages to miraculously recover. It’s either that or they ban the AfD.
Pretty sure their votes are just dumped in the trashcan.