** Shares of drugmaker Viatris rise as much as 9% to a three-month high of $12.65
** Stock set for best day in two years if gains hold
** Viagra maker's Q3 revenue of $3.74 bln beats Wall Street estimates of $3.71 bln, according to data compiled by LSEG
** Q3 adj EPS of 75 cents beats estimates of 68 cents
** YTD, stock up 16.2%
(Reporting by Puyaan Singh)
((Puyaan.Singh@thomsonreuters.com;))