Just a little addendum. The stock (LJPC) is up about 100% to 1.49 - 1.55 (actually 112%) but the volume is lite.
Why wouldn't BMRN buy them out considering their market cap was about 40-50 million before and according to Yahoo about half of it is cash? Biomarin said that their development is full now with what they have going and were happy to have LJPC continue it going (they weren't asked directly about buying the company/compound outright). The simple answer is it is much less risky this way and they basically LJPC pays for funding the development if it fails its not a mess for BMRN and if it succeeds BMRN would probably own about 1/3 of the company at that point in addition to getting half the sales.