(Adds details on drug, FDA review)
Oct 17 (Reuters) - AstraZeneca Plc said on Thursday that the U.S. drug regulator will give a speedy review to its experimental breast cancer treatment, which could put the British drugmaker in direct competition with bigger rival Roche Holding AG. The U.S. Food and Drug Administration (FDA) accepted AstraZeneca's application and granted the treatment, trastuzumab deruxtecan, a priority review for the treatment of HER2-positive metastatic breast cancer, the drugmaker said.
The London-listed company in March agreed to pay up to $6.9 billion to work with Japan's Daiichi Sankyo on the treatment, in a direct challenge to the world's biggest cancer drug maker Roche.
The treatment, also known as DS-8201, targets the HER2 protein, a major trigger of uncontrolled cell growth in about 20% of breast cancer cases. It is an area where Roche has been a pioneer with its best-seller Herceptin.
DS-8201 is part of a drug class called antibody-drug conjugates (ADC), which link powerful cell toxins to antibodies that cling to cancer cells, sparing the healthy cells that are damaged during conventional chemotherapy treatments.
The treatment showed promise in a mid-stage clinical trial in May, data from which formed part of the basis for AstraZeneca's application to the FDA.
The expedited review is part of the FDA's process to bring medications for serious or rare conditions faster to the market, taking about six months for a decision, compared to the standard 10 months.
The FDA's decision on trastuzumab deruxtecan is expected in the second quarter of next year.
AstraZeneca, which is set to report third-quarter results next week, has been betting on cancer medicines, an area of increasing focus after years of crumbling sales due to patent losses on older drugs.
Reporting by Pushkala Aripaka in Bengaluru; Editing by Bernard Orr and Rashmi Aich