In just about two years, Allergan PLC has gone from a pharma darling on the verge of a massively lucrative Pfizer Inc. buyout to something of a pariah.

Its stock has fallen 38 percent in the past nine months. Shareholders are reportedly recruiting activists. On its first-quarter earnings call on Monday, Allergan said it is in the midst of an “urgent” strategic review. But it also made it clear it doesn’t think the company needs a reinvention. It shouldn’t be so sure.