Arcus gains after TD Cowen starts coverage with 'buy' rating
** Shares of drug developer Arcus Biosciences RCUS.N rise 2% to $24.8 premarket after brokerage TD Cowen initiates the stock with a "buy" rating
** TD Cowen says co's kidney cancer drug candidate, Casdatifan, shrunk tumors of 45% patients in clinical trials, better than the current leading drug, Welireg, developed by Merck MRK.N
** Says upcoming trial data could de-risk co's Casdatifan program, estimated to generate about $4.1 billion in annual sales by 2035
** Co also advancing pancreatic cancer candidate drug quemliclustat and a broader immunology pipeline that could provide additional upside - TD Cowen
** As of last close, stock up 2.1% YTD