Gilead Sciences Inc. said its two hepatitis C drugs, Sovaldi and Harvoni, generated $4.8 billion in sales in the third quarter, topping Wall Street estimates for global sales of $4.47 billion.

Per-share earnings, excluding certain items, and overall revenue also beat expectations.

For the year, Gilead again raised its outlook for net product sales, this time by $1 billion, and now expects sales to reach $30 billion to $31 billion.

The Foster City, Calif., biopharmaceutical company, which traditionally had been know for its HIV/AIDS treatments, recently has seen its sales driven by its hepatitis C drugs.

Sovaldi and Harvoni represent two of the most successful drug launches ever, marked by their high cure rates, fewer side effects and imposing price tags. However, the drugs face competition from new hepatitis C treatments such as AbbVie Inc.’s Viekira Pak. Meanwhile, Merck & Co. is seeking U.S. regulatory approval for its combination treatment for hepatitis C.

During the third quarter, Sovaldi sales fell 48% to $1.47 billion.

Harvoni, which c ombines Sovaldi with another drug and was approved in October 2014, recorded sales of $3.33 billion in its fourth quarter on the market, down from $3.61 billion during the previous three-month period.

Analysts were expecting global sales of $1.16 billion for Sovaldi and $3.31 billion for Harvoni, according to a note by Evercore ISI analyst Mark Schoenebaum.

Mr. Schoenebaum said investors likely will be listening on the conference call for any full-year guidance on sales of Gilead’s hepatitis C drugs and how they are faring against Viekira. Investors also likely will be interested in comments on the company’s HIV therapies, drug pipeline and plans on how it plans to deploy its capital.

Overall, Gilead reported a profit of $4.6 billion, or $3.06 a share, up from $2.73 billion, or $1.67 a share, a year earlier. Excluding stock-based compensation, acquisition-related charges. and other items, per-share earnings rose to $3.22 from $1.84. Revenue climbed 37% to $8.3 billion.

Analysts polled by Thomson Reuters expected per-share profit of $2.87 and revenue of $7.82 billion.