Biotechnology giant Genentech Inc. is reporting a jump in first-quarter profits of 12 percent compared to last year as sales of its top-selling cancer drugs rose by double digits.

For the quarter ended March 31, the company earned $790 million, or 74 cents per share, compared with $706 million, or 66 cents a share, a year ago.

Excluding special expenses, Genentech said Thursday it would have earned $895 million, or 84 cents a share. On that basis, the results beat the average per-share estimate among Wall Street analysts by two cents, according to research firm Thomson Financial.

Revenue was $3.06 billion in the quarter, an increase of 8 percent from $2.84 billion a year ago. Sales of Genentech’s top two cancer drugs rose 13 percent.