Based on Kaplan–Meier survival estimates, it is estimated that
approximately 91%, 82%, and 76% of patients exposed to vigabatrin
would remain in the registry at 3, 6, and 12 months, respectively
(Fig. 3B). The percentages of patients exposed to vigabatrin who were
estimated to remain in the registrywas 69% at 18 months and 64% at 24
months. The percentages of patients naïve to vigabatrin remaining in
the registry were estimated to be 71% at 3 months, 55% at 6 months,
40% at 12 months, 34% at 18 months, and 28% at 24 months.
The most common (≥10%) reasons that prescribers selected for registry
discontinuation were the following: patient completed treatment
(36%), prescriber choice (23%), and patient choice (11%) (Table 3).
Clinicians reported that eight patients discontinued treatment
because of visual field defects (VFD). The patients ranged from ages 18
to 55 years at entry into the SHARE program and were divided equally
by gender. One 19-year-old patient was reported to have an indication
of IS, the other patients had CPS. Three patients entered the program
with previous vigabatrin exposure. The five patients who were newly
treated had vigabatrin discontinued by their clinicians because of VFD
after exposures of 13 months to 3.3 years (mean: 23 months). No
perimetry data after their time of discontinuation were available.