Biogen's S1P Modulator License – A Good Deal Done Too Late?

Biogen's license for the sphingosine 1-phosphate (S1P) receptor modulator MT-1303 from Mitsubishi Tanabe for up to $544m makes a lot of sense, but with four S1P-targeting drugs approved or in late-stage development did Biogen execute a good deal too late to catch up with the competition?