There is no limit on the number a times a case can be continued. There is an urban legend that each side gets three continuances, but that is just not the case.
The real question is whether the prosecution has met their obligations under Rule 600, which is Pennsylvania’s speedy trial rule. Under Rule 600 the prosecution has to bring the defendant to trial within one year of the charges being filed. However, the clock stops whenever there is a delay caused by the defendant or by the court calendar. So whenever the defendant files a motion or requests a continuance the clock stops. And if the criminal docket is backed up to the point that there was simply no court time available to try the case, the clock stops then as well. Delays caused by the prosecution do not stop the clock if the defense objects to those delays.