"Trigen has demonstrated that with flovagatran, anti-coagulation can be rapidly established and stably maintained without dose adjustment. On cessation of therapy flovagatran is rapidly and predictably cleared."
This suggests that your observation that Solulin's long action might not be ideal in acute care applications might have occurred to PAION as well.
Another tidbit from the Trigen site:
"Where appropriate, particularly during the late stages of the clinical development and approval process and the commercialization phase, PAION seeks to collaborate with experienced partners. At 31 December 2007, PAION had 53 full-time equivalent employees."