** Shares of Dimerix DXB.AX rise as much as 6.9% to A$0.545, their highest level since September 19
** Japan gives "orphan drug" designation to biopharmaceutical firm's DMX-200 drug for treating focal segmental glomerulosclerosis, a rare type of kidney disease
** Japan gives orphan drug designation to treatments if they are intended for use in less than 50,000 patients in Japan, and for which there is a high medical need
** Co says "orphan" drug designation provides for incentives including extended market exclusivity period of 10 years and price premiums
** More than 2.4 million shares change hands, 1.9 times the 30-day average
** Stock up 16.7% so far in September after two straight months of losses
** Stock up 54.4% YTD, including the day's moves
(Reporting by Nikita Maria Jino in Bengaluru)
((Nikita.Jino@thomsonreuters.com;))