Inclusion Criteria:

• Patients who have completed through Week 41 visit in the TKT025 study.
• Patients must have voluntarily signed an IRB/EC approved informed consent form after all relevant aspects of the study have been explained and discussed with the patient.
• Patient must be sufficiently cooperative to participate in this clinical study as judged by the Investigator.
• Female and male patients of child bearing potential must agree to use a medically acceptable method of contraception at all times during the study. Female patients must have a negative serum pregnancy test on enrollment.

Exclusion Criteria:

• Patient has received treatment with an investigational therapy within the past 30 days other than GA-GCB.
• Patient has a clinically relevant medical condition (e.g., HIV, hepatitis B or C) that would make implementation of the protocol difficult and/or confound an assessment of the effects of the experimental therapy and its adverse events.
• Patient, patient's parent(s), or patient's legal guardian is unable to understand the nature, scope and possible consequences of the study.
• Patient is unable to comply with the protocol, e.g. uncooperative attitude, medical condition, inability to return for safety evaluations, or is otherwise unlikely to complete the study, as determined by the Investigator.