A new treatment landscape for triple-negative breast cancer

A concerted R&D effort directed at triple-negative breast cancer patients promises new treatment options in the near future, according to latest research from independent market analyst, Datamonitor.

Triple-negative breast cancer is characterised by high unmet need. While some triple-negative breast cancer patients now have an additional treatment option in the form of Avastin (bevacizumab; Roche/Genentech/Chugai), the drug faces possible removal of its breast cancer indication in the US by the Food and Drug Administration (FDA) following an Oncologic Drugs Advisory Committee’s (ODAC’s) recommendation. Datamonitor estimates that Avastin derives $540m from use in triple-negative breast cancer in the US alone. The US position may also impact regulatory reviews in international markets—Avastin is not yet approved for the treatment of breast cancer in Japan, and in Australia it is restricted to use in combination with chemotherapy agent paclitaxel.

Andrew Paramore, analyst at Datamontior, comments: “Regardless of any decision over Avastin, the need remains for more effective therapies. New poly (ADPribose) polymerase (PARP) inhibitors, such as Sanofi Aventis’s iniparib, have the potential to meet this need. Iniparib’s ability to improve survival in triple-negative breast cancer patients could potentially alter the treatment landscape of this indication”.

In Iniparib’s Phase II trial, the drug significantly prolonged both progression-free survival and median overall survival compared with chemotherapy alone in the first-line treatment of triple-negative breast cancer patients.

Andrew adds: “If iniparib’s mechanism of action is validated in the ongoing Phase III trial, it could lead to the development of a new generation of drugs targeting the DNA repair process.

“Furthermore, other than offering improved treatment options for triple-negative breast cancer, iniparib could be exploited in other tumour types that express known defective DNA repair enzymes. In lung cancer, for example, mutations in DNA repair enzymes, including BRCA-1 have been linked with different levels of sensitivity to chemotherapy or radiotherapy.”

In spite of the positive data to date, it should be noted that strong conclusions on the drug’s efficacy cannot be made based on this Phase II trial, which is limited by the small patient number and the fact that its primary endpoint was clinical benefit response rather than progression-free or overall survival.

By the end of 2010, Datamonitor estimates that 484,600 women will be diagnosed with breast cancer in the seven major markets** during the year. Between 2010 and 2019 total breast cancer incident cases in the seven major markets are forecasted to increase by 13% to 548,000 annual incident cases by the end of 2019.

www.datamonitor.com