[Revolade (a/k/a/ Promacta/eltrombopag) probably won’t be a blockbuster, but it could well be a solid midsized drug for GSK and LGND (who gets a royalty on sales). Promacta was approved in the US in Nov 2008 (#msg-33719480); its main competitor is AMGN’s Nplate which, unlike Revolade, is injected. A positive opinion by the CHMP is tantamount to formal approval with a delay of 2-3 months for rubber stamping by the EU Commission.]
What do you have in mind for "solid midsized drug"? It may not impact GSK's bottom-line much and therefore stock, but it could presumably have an impact on LGND given its roughly $200 million market cap.
An important consideration, of course, is the royalty due to LGND and I don't recall if it is single-digit, double-digit, or not disclosed.
EDIT
Per the most recent 10-Q:
"As part of a settlement agreement and mutual release we entered into on February 11, 2009 with The Rockefeller University, or Rockefeller, we agreed to pay a share of such royalties to Rockefeller. Accordingly, after paying Rockefeller, we are entitled to retain tiered royalties in the range of 4.7%—9.3% on annual net sales of PROMACTA."