According to this report from the Timorous Me forums:

Last night Ted Leo announced on-stage at his Glasgow show that it would be the last of the tour, and that all further shows on the tour would be cancelled.

He stated that he had to return to New Jersey. It appeared to be for personal reasons as details were sparse.

The band nonetheless played a spectacular show with all the energy you would expect from Ted Leo and the Pharmacists. To close the show, Ted threw off his guitar, narrowly missing the drumkit, and leapt into the arms of the crowd. And so it was that a Glasgow audience (in a city that was that day victim of a terrorist incident) and a legendary man (who had clearly had some sort of bad news, whatever that may have been), supported each other as a difficult day came to a close.

We haven't yet heard any reports to confirm or deny this news, but if it is, our thoughts go out to Ted and the band during this difficult time.