Pfizer's sales dipped 9 percent in the fourth quarter of 2019 after the drugmaker lost patent protection on its blockbuster painkiller Lyrica, according to The Wall Street Journal.
Pfizer posted sales of $12.69 billion in the fourth quarter, compared to $13.98 billion in sales in the same period one year prior.
Pfizer's Upjohn unit, which includes Lyrica and the erectile dysfunction pill Viagra, saw its sales decline 32 percent in the fourth quarter. Lyrica in particular saw sales sink 68 percent due to competition from generics, according to CNBC.
Overall in the fourth quarter, the drugmaker reported a net loss of $337 million,compared to a loss of $394 million in the same period last year.
Pfizer's Upjohn unit is merging with Mylan to form a new pharmaceutical company. That transaction is expected to close later this year.