Incidence of opportunistic infection, malignancy and PML during the first 3 years of natalizumab treatment, after 3 years of natalizumab treatment and across the entire treatment period
| Event | ≤3 years (n=6148) | >3 years (n=3719) | Overall (n=6148) |
| Patient-years of follow-up* | 15 773.19 | 10 233.77 | 26 060.25 |
| Opportunistic infection | |||
| Patients with an event, n (%) | 10 (0.16) | 1 (0.03) | 11 (0.18) |
| Incidence rate (95% CI)† | 0.634 (0.341 to 1.178) | 0.098 (0.014 to 0.694) | 0.422 (0.234 to 0.762) |
| PML | |||
| Patients with an event, n (%) | 17 (0.28) | 36 (0.97) | 53 (0.86) |
| Incidence rate per 1000 patient-years (95% CI)† | 1.078 (0.67 to 1.734) | 3.518 (2.537 to 4.877) | 2.034 (1.554 to 2.662) |
| Malignancy | |||
| Patients with an event, n (%) | 35 (0.57) | 28 (0.75) | 63 (1.02) |
| Incidence rate (95% CI)† | 2.219 (1.593 to 3.090) | 2.736 (1.889 to 3.963) | 2.417 (1.889 to 3.095) |
Serious adverse event timing is determined based on event start date. Patients with >1 event are counted only once.
*Based on the time from the first dose of natalizumab until the last natalizumab dosing date + 6 months.
†Calculated as (1000 × number of patients with an event) / (total patient-years of follow-up). Exact CIs are calculated based on the Poisson distribution.
PML, progressive multifocal leukoencephalopathy.