This story makes no sense, if he is resigning to pursue other interests, he would not be paid a continuation benefit. Since he is being paid, I assume he was fired.
...On Tuesday, ImmunoGen announced that Chief Financial Officer Gregory Perry intends to resign from the company "to pursue other interests,". ...Perry will be paid a "salary continuation benefit" equal to 12 months' salary. His salary is currently listed at $477,958, according to S&P Capital IQ.