(Reuters) -Drugmaker Pfizer (PFE) posted a better than expected fourth quarter profit on Thursday, helped by cost cuts and a smaller-than-feared drop in sales of its COVID-19 vaccine.

"Our revenue volatility is largely in the past as COVID-related uncertainties have diminished," Pfizer's finance chief David Denton said in prepared remarks.

Pfizer's shares rose 2% in premarket hours. The stock fell nearly 8% last year, and trades at less than half its value at the peak of the COVID-19 pandemic.

Pfizer's COVID product sales have fallen sharply from their highs of the pandemic, but are still a profit driver for Pfizer.

Revenue from COVID vaccine Comirnaty brought in sales of $3.38 billion, while antiviral treatment Paxlovid was $727 million for the quarter. Pfizer makes the Comirnaty vaccine with German partner BioNTech.

Analysts were expecting $3.10 billion for Comirnaty and quarterly sales of $794.33 million for Paxlovid, according to data compiled by LSEG.

Sales of its heart disease drug, sold as Vyndaqel and Vyndamax, came in at $1.55 billion, above estimates of $1.48 billion.

The company is under scrutiny from investors who are eager to see profitable returns from its recent acquisitions, including its $43 billion purchase of cancer drugmaker Seagen, and internal investments.

Quarterly sales of cancer therapy Padcev, acquired with Seagen, came in at $444 million, compared with estimates of $440 million.

The company implemented cost-cutting measures and expects to save $4.5 billion by the end of this year, and another $1.5 billion by simplifying its manufacturing operations by 2027.

On an adjusted basis, Pfizer earned 63 cents per share for the fourth quarter, compared with analysts' estimates of 47 cents per share.

(Reporting by Manas Mishra and Bhanvi Satija in Bengaluru and Michael Erman in New York; Editing by Saumyadeb Chakrabarty and Nick Zieminski)