Is the IMS data something that's publically available or at least available to some large degree…
The data are available by subscription only. The price of a subscription is high enough that most subscribers are large institutions.
…is it likely that the figures you cited should already theoretically be well known to a lot of investors and thus reflected into the share price?
Well, we can be pretty sure the figures were not known to certain posters on this board who were forecasting a minuscule market share for generic Lovenox :- )
…are these figures that have just been released?
The figures for the week ending Aug 20 were available to subscribers last week, so the answer is no.
“The efficient-market hypothesis may be the foremost piece of B.S. ever promulgated in any area of human knowledge!”