BUZZ-AstraZeneca cancer drug faces new competition from Tesaro

** AstraZeneca (NYSE: AZN - news) off 0.5% after Tesaro (Frankfurt: A1J0WH - news) wins U.S. approval for ovarian cancer drug Zejula (niraparib), a rival so-called PARP inhibitor to UK firm's Lynparza

** Zejula also wins approval for broader use in women than either Lynparza or Clovis Oncology (Frankfurt: C6O.F - news) 's Rubraca, both of which are limited to women with tumours with specific genetic mutation

** However, Barclays (LSE: BARC.L - news) analysts don't expect Zejula to materially displace Lynparza in the segment of the market where it is established and has competitive data

** Astra reported impressive clinical trial results with Lynparza earlier this month

** Lynparza became the first of new PARP drug class to reach the market when it won U.S. approval at the end of 2014