** Shares of Ascentage Pharma Group International 6855.HK drops 6.3% to HK$70, their lowest since June 23
** Stock on track for the biggest one-day pct fall since May 7; fourth biggest pct loser in Hang Seng Biotech Index .HSHKBIO, which is up 1%
** The Chinese co, which develops small-scale therapies for cancers and hepatitis B virus, plans sale of 22 mln new shares to Dajun Yang Dynasty Trust, a family trust established by the company's chairman and key shareholder Yang Dajun
** The new shares will be issued at HK$68.6 apiece, or 8.2% discount to Monday's close of HK$74.70 each
** Sale is to raise HK$1.5 bln ($191.1 mln) for clinical development to advance core pipeline candidates, among others
** Trust to buy new shares following sales of the same amount of existing shares at the same price to third party investors
** Stock on course for a fourth straight session of decline
** Hang Seng Index .HSI adds 0.2%
** YTD, stock up 57.9%
($1 = 7.8498 Hong Kong dollars)
(Reporting by Donny Kwok)
((donny.kwok@thomsonreuters.com))