** Shares of drug developer Aptevo Therapeutics APVO.O rise 84% to $2.60 premarket
** On Wednesday, co in a filing said that hedge fund billionaire Steven Cohen's firm has taken a 9.1% stake in APVO
** Point72 Asset Management, founded by Cohen in 2014, now holds 299,944 shares of Aptevo
** The firm has shared voting and dispositive power over the shares
** On Tuesday, APVO said its experimental cancer therapy led to 100% remission in an early-to-mid stage trial
** As of last close, stock down 98% YTD