This is a Phase 3, open-label, multi-center trial to evaluate the long-term safety, efficacy, and immunogenicity of up to four continuous treatment cycles of daxibotulinumtoxinA (DAXI) for injection at doses of 125 U, 200 U, 250 U, or 300 U in adults with isolated cervical dystonia (CD). Approximately 290 adult subjects will be recruited from study centers in the United States, Canada, and Europe who were enrolled in Study Protocol 1720302. These subjects from Study 1720302 include: Those with insufficient efficacy to study treatment or had no improvement at Week 6, and the investigator agreed that there was a need for retreatment based on the subjects symptoms and neurologic exam; Those who benefited from study treatment and completed all follow-up study visits up to the time point of when the target TWSTRS score was reached or exceeded (Comella et al. Neurology 2005); Those who benefited from study treatment but subsequently experienced significant recurrence of CD symptoms (e.g. pain) during the study before reaching the target TWSTRS score and the investigator determined that early study completion was warranted, and there was a need for retreatment based on the subjects symptoms and neurologic exam; Those who completed all study visits up to Week 36 and never reached their target TWSTRS score, and the investigator determined that these subjects can roll over and be followed in the OLS until retreatment is clinically indicated. All subjects will have up to 7 days from their End-of-Study (EOS) Visit in Study Protocol 1720302 to decide if they want to rollover to the OLS. After the 7-day decision-making period, any subjects who have not made a decision regarding rollover status will be considered not interested in the OLS. After a subject has decided to rollover into the OLS, s/he will have up to 21 days to complete the screening procedures and enroll in the OLS. After 21 days, subjects who have NOT completed the screening procedures will be considered a screen failure. To be reconsidered for enrollment to the OLS, the subject will be required to repeat all screening procedures to reconfirm eligibility for enrollment in the OLS. These criteria also apply to subjects who missed the 7-day decision-making window to rollover to the OLS.

You may be eligible for this study if you meet the following criteria:

• Conditions: Medical Research
• Age: 99 years or below
• Gender: All