As I suspected, something material has happened that we're not fully aware of. My thoughts are:
(1) GSK offered BTA a serious attempt at tackling the stockpiling market in light of the recent research favouring Relenza over Tamiflu;
(2) GSK and BTA/Sankyo entering into a partnership deal on LANI which would dwarf any higher settlement on Relenza;
There is just no way that BTA management would have dumped the legal action without some sort of reward. And that "reward" may still be hidden from shareholders with some hints in the cryptic words of the announcement.
Check out the latest from around the world... there is going to be a massive push for Relenza in the next few years... they have just been handed a MASSIVE compeditive advantage i.e. Tamiflu resistant strains of H5N1 and other influenza.
Disease pandemic 'inevitable' in Britian warns House of Lords http://www.telegraph.co.uk/news/newstopics/politics/health/2437908/Disease-pandemic-inevitable-in-Britian-warns-House-of-Lords.html
The team discovered that when this mutation occurred the virus became resistant to Tamiflu, although it was still affected by Relenza.