Updates
** Shares of Soleno therapeutics SLNO.O rise 33.7% to $52.80 premarket
** Neurocrine Biosciences NBIX.O says it will buy Soleno in a deal worth $2.9 billion
** Neurocrine will pay $53 per share in cash for Soleno, a premium of 34.2% to Soleno's last close
** The deal is expected to close within 90 days, cos say
** Neurocrine shares were down 2.7% at $128 before the bell
** The deal gives Neurocrine access to Vykat XR, the first drug approved in the U.S. to treat hyperphagia associated with Prader-Willi syndrome, a rare genetic disorder
** Up to last close, SLNO has fallen 14.7% this year
(Reporting by Mrinalika Roy and Kamal Choudhury)