This is an open-label, multicenter, non-randomized, long term extension study. Total study duration is expected to be up to 2 years, with a maximum of 3 years. Participants who have completed the previous GW906 Injection study will be assessed for eligibility at the screening visit of this study. Those who meet the eligibility criteria will receive the first dose of the extension treatment. Participants enrolled in this study will be preferentially assigned to Cohort 1. After enrollment into Cohort 2 has been initiated, participants will be assigned to receive treatment of the Cohort 2.
