Genentech drug wins expanded approval

The Food and Drug Administration agreed to expand the use of Genentech Inc.’s breast cancer drug Herceptin to include some women with early-stage cancer who have undergone surgery, the company said Thursday.

Herceptin is used to treat the 25% to 30% of breast cancer patients who have tumors that generate a protein called HER-2. Those tumors tend to grow faster and are more likely to recur than tumors that do not carry the protein.

The FDA’s initial approval of the drug in 1998 covered only those women whose cancer has spread beyond the breast. However, physicians have been using Herceptin in combination with chemotherapy in earlier-stage cancer since the 2005 announcement of positive trial results for such patients.

Herceptin is designed to target tumor cells and spare normal cells, unlike chemotherapy, which can be toxic to both.

In the first nine months of this year, U.S. sales of Herceptin rose 84% from the same 2005 period to total $912 million.

Formal FDA approval “is unlikely to provide a sharp uptick in Herceptin sales,” given the drug’s extensive off-label use, Citigroup analysts said in a report issued last week.

Citigroup said the post-surgery area was the most significant opportunity for Herceptin with both larger patient populations and a potentially longer duration of treatment than in the metastatic setting.

The FDA’s decision on the new indication for Herceptin had been expected in August, but the decision was delayed after the agency requested more data.

Genentech, the world’s No. 2 biotechnology firm, is majority-owned by Swiss drug maker Roche Holding. The South San Francisco-based company’s shares rose about 1% to $81.80 in late trading after news of the FDA’s action was released. In regular trading, the stock climbed 28 cents to $80.72.