The Food and Drug Administration on Tuesday approved a
drug designed for women with a type of breast cancer that has progressed even after they were given other therapies.
Specifically, Tykerb was cleared for women with advanced breast cancer or breast cancer that has spread to other organs. The drug, which is targeted for about 25% of breast-cancer cases, must be used with a chemotherapy agent, Xeloda, made by
. Tykerb will be available in two weeks.
The FDA's approval gives a boost to GlaxoSmithKline's effort
to expand its modest cancer business and offers potential competition to Herceptin from
. Herceptin produced $1.23 billion in sales last year, up 65% from 2005.
Herceptin was approved by the FDA in September 1998 in combination with another cancer drug as a first-line breast-cancer treatment. It also can be used as a single therapy after other drugs have failed.
Tykerb isn't approved as a first-line therapy. Genentech's Herceptin is one of three medications cited by the FDA as needing to have been tried before doctors can administer Tykerb. The GlaxoSmithKline drug is a once-a-day pill, while Herceptin must be injected once every seven days.
Both drugs target a tumor that exhibits a protein called HER2. According to the FDA and the American Cancer Society, an estimated 8,000 to 10,000 U.S. women die annually from HER2 breast cancer.
The FDA says Tykerb differs from Herceptin because the GlaxoSmithKline drug can enter tumor cells to block the action of HER2 and other proteins. Herceptin attacks the HER2 protein on the outside of tumor cells. Thus, Tykerb can work in some HER2 breast cancers that no longer respond to Herceptin.
"New targeted therapies such as Tykerb are helping expand options for patients," said Dr. Steven Galson, director of the FDA's Center for Drug Evaluation and Research.
Tykerb's approval was expected thanks to clinical trials that assessed how fast tumors would grow after treatment. A test involving 399 participants showed the median time to disease progression was 27.1 weeks for patients receiving the combination of drugs vs. 18.6 weeks for those receiving Xeloda alone. This test was conducted with women whose tumors were growing after they had received other cancer drugs, including Herceptin.
"We are dedicated to the further study and development of Tykerb in a variety of settings, including adjuvant breast cancer, as well as in other solid tumor types," said Dr. Paolo Paoletti, senior vice president of the oncology medicine development center at GlaxoSmithKline.
The company is testing Tykerb for cancers of the kidney, head and neck. It has filed breast-cancer applications with the European Union, Canada, Australia, Switzerland, Brazil and South Korea.