Herceptin study: No rise in heart failure risk

CHICAGO (CNNMoney.com) -- The heart failure risk associated with breast cancer treatment Herceptin does not increase over time, according to a study that could help alleviate concerns over Genentech's blockbuster drug.

The incidence of congestive heart failure was relatively flat for patients taking Herceptin for three and five years, according to study results announced Sunday at the annual conference of the American Society of Clinical Oncology. The study tracked 1,850 Herceptin patients.

For Herceptin patients on the medication for five years, the risk of congestive heart failure was 3.8 percent. The rate for patients after three years was 4.1 percent, according to research findings.

Herceptin is one of Genentech's (Charts) top-selling drugs and is growing rapidly, with total sales of $1.2 billion in 2006, a 65 percent surge from the year before. The heart failure risks of Herceptin are well-known and are included in the drug's FDA-approved warning label.

The fresh data might help Genentech allay fears over the drug's heart risks.

"While we need to continue monitoring patients closely for late cardiac effects, this is reassuring news for women taking this drug," said Dr. Priya Rastogi, lead researcher in the study and assistant professor of medicine at the University of Pittsburgh Cancer Institute, in a prepared statement.

Dr. Rastogi said heart failure was present is 0.9 percent of breast cancer patients taking chemo without Herceptin, meaning that Genentech's drug approximately quadruples the risk. She said the additional data could help doctors assess an individual patient's risk on a case-by-case basis.

Herceptin is effective in women with a specific gene called HER2, which is present in about one-fourth of all breast cancer patients. Studies have shown that Herceptin with chemotherapy can block the recurrence of cancer by 52 percent over three years compared to chemo alone.

Breast cancer is a common disease, affecting one in eight women, according to the National Institutes of Health. The disease also affects men, but at much lower rates. About 180,000 women and 2,000 men were diagnosed with breast cancer in the U.S. so far this year, and 40,000 patients have died, according to estimates from the National Cancer Institute.

Genentech is the world's second-biggest biotech by sales, behind industry leader Amgen (Charts, Fortune 500).

Genentech's top-selling drug is Rituxan, a treatment for non-Hodgkin's lymphoma and rheumatoid arthritis, with $2 billion in 2006 sales. The company's No. 2 product is fast-growing Avastin, a treatment for colorectal and lung cancer with $1.7 billion in 2006 sales, a 54 percent jump from the year before.