** Shares of UK biotherapeutics company Puretech Health
PRTC.L rise as much as 11% to 225.5p in early trade
** Stock is top pct gainer across all London stocks
** Co enters into royalty agreement for Karuna Therapeutics'
investigational drug KarXT with U.S.-listed Royalty Pharma
RPRX.O for up to $500 mln
** As part of this deal, PRTC sold its right to receive a 3%
royalty from Karuna to Royalty Pharma on sales of up to $2
billion annually, after which threshold Royalty Pharma will
receive 33% and PRTC will retain 67% of royalty payments
** PRTC retains its current equity stake in Karuna in
addition to milestone payments and 20% of sub-license revenues
due to Co
** Stock down 16.51% YTD, as of last close
(Reporting by Shreyaa Narayanan in Bengaluru)
((Shreyaa.Narayanan@thomsonreuters.com))