US approves new targeted breast cancer drug

The US Food and Drug Administration has approved a first-of-a-kind breast cancer medication that targets tumour cells while sparing healthy ones.

The drug Kadcyla from Roche combines the established drug Herceptin with a powerful chemotherapy drug and a third chemical linking the medicines together. The chemical keeps the cocktail intact until it binds to a cancer cell, delivering a double-shot of anti-tumour poison.

Cancer researchers say the drug may offer a clear advantage over older drugs because it delivers more medication with fewer side effects.

The FDA approved the new treatment for about 20 per cent of breast cancer patients with a form of the disease that is typically more aggressive and less responsive to hormone therapy. These patients have tumours that overproduce a protein known as HER-2.

The approval will help Roche's Genentech unit build on the blockbuster success of Herceptin, which has long dominated the breast cancer marketplace. The drug had sales of roughly USD 6 billion last year.

Genentech said today that Kadcyla will cost USD 9,800 per month, compared to USD 4,500 per month for regular Herceptin. The company estimates a full course of Kadcyla, about nine months of medicine, will cost USD 94,000.

FDA scientists said they approved the drug based on company studies showing Kadcyla delayed the progression of breast cancer by several months. Researchers reported last year that patients treated with the drug lived 9.6 months before death or the spread of their disease, compared with a little more than six months for patients treated with two other standard drugs, Tykerb and Xeloda.

Overall, patients taking Kadcyla lived about 2.6 years, compared with two years for patients taking the other drugs. FDA specifically approved the drug for patients with advanced breast cancer who have already been treated with Herceptin and taxane, a widely used chemotherapy drug.

Kadcyla will carry a boxed warning, the most severe type, alerting doctors and patients that the drug can cause liver toxicity, heart problems and potentially death.
The drug can also cause severe birth defects and should not be used by pregnant women.