GSK Files Breast Cancer Drug Tykerb For US OK

Armen Hareyan's picture

Breast Cancer and Glaxo

British drugmaker GlaxoSmithKline Plc (GS) Monday said it has submitted experimental breast cancer drug Tykerb for approval in the U.S. for use in the treatment of advanced breast cancer.

GlaxoSmithKline filed for approval to sell Tykerb in combination with Roche Holding AG's (RHHBY) chemotherapy drug Xeloda for treatment of a particularly aggressive kind of tumor that produces the protein HER-2. About 20% to 30% of women with breast cancer have this form of the disease.

The U.S. Food and Drug Administration has granted fast-track status, a designation that expedites the approval process. In Europe, GlaxoSmithKline plans to file for approval during the fourth quarter this year.

The filing was based on a study that showed that Tykerb was effective at treating this kind of breast cancer in patients who don't respond to Herceptin, a Roche drug, giving hope to women with otherwise limited treatment options.

When taken with a standard chemotherapy treatment in a clinical study, Tykerb nearly doubled the time to 8.5 months before the average patient's breast cancer got worse compared with chemotherapy alone. No significant extra side effects were experienced with Tykerb and chemotherapy, compared with those taking just chemotherapy.

Herceptin, which was developed by Genentech Inc. (DNA), a U.S. biotechnology company majority-owned by Roche, is the most-widely prescribed drug for this kind of breast cancer.


Herceptin has been on the market for several years, but is still gaining market shares. New research published last year showed that using Herceptin after chemotherapy in the early stages of the disease reduce the risk of cancer recurring by nearly 50%, compared with chemotherapy alone.

This news prompted many physicians to begin prescribing Herceptin for earlier states of the disease, even before it won regulatory approval for that use.

Analysts say it will be tough for Tykerb to compete with Herceptin.

"This indication (in advanced breast cancer) isn't significant, and Glaxo is of course trying to move into earlier stages of the disease," said Denise Anderson, analyst at Kepler Equities who has a hold rating on GlaxoSmithKline.

But the British company may find it difficult to conduct clinical trials in Europe and the U.S., where Herceptin is already used, and is currently conducting further studies on the drug in countries where the rival product isn't available.

Shares in GlaxoSmithKline showed slight reaction to the Tykerb announcement. At 1406 GMT they were 0.3% higher, or up 4 pence at 1471 pence, in a higher U.K. market.