How long will vacuum packed steak last in fridge?

Over a year.

A year is a stretch but it will not last a year in your typical kitchen freezer which is opened and closed everyday.(during these opening and closing temperatures are rising and lowering resulting in slow water loss and chemical changes) HOWEVER if you put this in one of those NON DEFROSTING CABINET freezers the steak will last many months longer maybe up to a year.

NOTE- Most of our commercially frozen foods are stored in very large frozen food warehouses where the temperature may only vary about +2 degrees during their storage life about 0 degrees F to -5 degrees F. Therefore their shelf life will last a lot longer time than our home freezers. Although I wouldn't recommend eating , but I have eaten steaks that have been vacuumed packed for as long as three years . No lost of flavor , and tender, freezer is set to 0' not opened on a daily basis .