Updated from 5:44 p.m. EDT

Genentech ( DNA) beat revenue and earnings estimates for the third quarter and said sales from two of its biggest drugs rose at least 70% from a year ago.

The biotech giant's revenue was $1.75 billion, up 46% from the third quarter of 2004. On average, analysts expected $1.63 billion. Total product sales were $1.45 billion.

Among its cancer drugs, the company reported that U.S. Avastin sales were up 78% to $325.2 million. Domestic Herceptin sales increased 70% to $215.1 million, while U.S. sales of Tarceva, launched last November, totaled $73.2 million. Rituxan, used to treat cancer of the lymph nodes, saw U.S. sales rise 16% to $456.2 million.

The South San Francisco, Calif., company earned 33 cents a share, up 57% from 21 cents in the year-ago quarter. Excluding certain costs, the company earned 35 cents a share in the third quarter, 5 cents better than analysts anticipated.

Genentech shares rose $4.31, or 5.3%, to $85.81 in after-hours trading Monday.

For all of 2005, Genentech is currently expecting year-over-year non-GAAP earnings per share growth of around 50%. Based on a non-GAAP profit of 83 cents a share for 2004, that forecast would imply earnings of about $1.25 a share this year, before any items.

On a conference call, Genentech noted that it may run the risk of eventually becoming a victim of its own achievements. The company says that the positive revenue and earnings news could create the belief that this caliber of performance will continue, and the "success of Avastin and Herceptin may create unrealistic expectations."

Regarding the U.S. Patent and Trademark Office's re-examination of the company's Cabilly patent, Genentech said it could take from two to 12 months to hear from the office.

Overall pretax income related to the patent was about $20 million, or 1 cent a share, for the quarter. Genentech said its third-quarter Cabilly-related income represents roughly one-quarter of the full year's expected results.

Separately, recent independent investigations have shown that Avastin is effective against an eyesight-robbing disease called wet age-related macular degeneration, a condition Genentech is hoping to treat with an experimental drug called Lucentis.

For investors, the concern would be that even if Lucentis gets regulatory approval, Avastin could be used as a cheaper treatment for the condition. That would mean the company runs the risk of cannibalizing its own sales with an already existing product.

However, Genentech says using Avastin for the eye disease might involve even greater risks than lost sales.

"Avastin and Lucentis are two different drugs, designed and developed to treat two different diseases," says Susan D. Desmond-Hellmann, president of product development at Genentech. Desmond-Hellmann says she's confident in Lucentis as a treatment for wet AMD, but she can't say the same for Avastin.

Genentech says it's in discussions with the Food and Drug Administration regarding a change in the label for Avastin to indicate that the cancer drug isn't suitable for intraocular use.