Genentech Inc.'s Activase alteplase tissue plasminogen activator (tPA), a thrombolytic, is the only drug approved by the FDA to treat acute ischemic stroke. But its use is hampered by the need to treat patients within a 3-hour window after symptom onset, a window that GNE would like to open further. However, data from several past trials and a new trial reported last week indicate that the 3 hour limit may be the best that any thrombolytic therapy in stroke will be able to achieve.

The termination last week of ATLANTIS, GNE's Phase III trial focused on patients treated between 3