Ligand Pharmaceuticals Inc. said Thursday it received a $2 million milestone payment from Merck & Co. as part of a research collaboration.
The company said the partnership covers a range of research programs. It is due to expire at the end of December.
Ligand had revenue of $27.3 million in 2008. The company makes the pain treatment Avinza.
Shares of Ligand fell 12 cents to $2.24 in midday trading.