In patients treated with natalizumab, PML incidence was about 11 cases per 1000 patients with 25 to 48 months of treatment, prior immunosuppressant use, and anti–JC virus antibody–positive status. The incidence was estimated to be 0.09 cases or fewer per 1000 antibody-negative patients.

Patients with atherosclerotic vascular disease were randomly assigned to receive the thrombin antagonist vorapaxar or placebo. Vorapaxar reduced the rate of subsequent cardiovascular death, myocardial infarction, or stroke but increased the rate of moderate or severe bleeding.

In this phase 2B trial involving 75 patients with acute ischemic stroke, tenecteplase was more effective than alteplase in achieving reperfusion and clinical improvement at 24 hours. Bleeding complications were similar in the two groups.

Patients with a cryptogenic stroke or transient ischemic attack (TIA) who had a patent foramen ovale were randomly assigned to closure with a percutaneous device or to medical therapy. There was no significant between-group difference in the subsequent rate of stroke or TIA.

In this placebo-controlled, phase 3 trial involving patients with relapsing–remitting multiple sclerosis, oral laquinimod administered once daily reduced the number of clinical relapses and slowed disability progression.

In patients with moderate or severe Alzheimer's disease receiving donepezil, those assigned to continue donepezil had less cognitive decline than did those assigned to discontinue donepezil. The combination of donepezil and memantine did not confer benefits over donepezil alone.