Leerink analyst Seamus Fernandez notes that Tesaro (TSRO) reported Q2 earnings with $25.9M in Zejula sales during its first quarter on the market following approval for second-line or greater ovarian cancer maintenance, more than doubling consensus estimates. With more than 1,500 new patient starts in the quarter, Zejula is off to a "strong" initial launch, he adds. However, the analyst believes it will likely soon face competition from Clovis' (CLVS) Rubraca and AstraZeneca's (AZN) Lynparza following their likely approvals in this setting. Fernandez reiterates a Market Perform rating and $143 price target on Tesaro's shares.