Follow-up Study for Patients Who Completed Study ALX0681-C301 (Post-HERCULES)

Primary outcomes

1. Percentage of Participants With Acquired Thrombotic Thrombocytopenic Purpura (aTTP) Related Events

   Time frame: From Baseline up to 36 months

   aTTP-related events were defined as: aTTP-related death, recurrence of aTTP (defined as recurrent thrombocytopenia requiring initiation of daily PE) or at least one major thromboembolic event (e.g., myocardial infarction, cerebrovascular accident, pulmonary embolism, or deep venous thrombosis). Percentage of participants with at least one aTTP-related events during the study were reported in this outcome measure.

2. Number of Acquired Thrombotic Thrombocytopenic Purpura-related Events

   Time frame: From Baseline up to 36 months

   aTTP-related events were defined as: aTTP-related death, recurrence of aTTP (defined as recurrent thrombocytopenia requiring initiation of daily PE) or at least one major thromboembolic event (e.g., myocardial infarction, cerebrovascular accident, pulmonary embolism or deep venous thrombosis).

3. Time to First Acquired Thrombotic Thrombocytopenic Purpura-related Events

   Time frame: From Baseline up to 36 months

   Time to first aTTP-related events was defined as the duration of time (in days) from Baseline up to first aTTP-related event in LTS16371. Participants without an event during LTS16371 were censored at the end of the study. Kaplan-Meier method was used for the analysis.

4. Number of Participants With aTTP Related Deaths Reported During the Study

   Time frame: From Baseline up to 36 months

5. Percentage of Participants With Recurrence of Disease (aTTP)

   Time frame: From Baseline up to 36 months

   Recurrence of aTTP was defined as recurrent thrombocytopenia requiring initiation of daily PE.

6. Number of Disease (aTTP) Recurrence Reported During the Study

   Time frame: From Baseline up to 36 months

   Recurrence of aTTP was defined as recurrent thrombocytopenia requiring initiation of daily PE.

7. Time to Recurrence of Disease (aTTP)

   Time frame: From Baseline up to 36 months

   Time to first recurrence of disease (aTTP) was defined as the duration of time (in days) from Baseline up to first recurrence of aTTP event in LTS16371. Recurrence of aTTP: defined as recurrent thrombocytopenia requiring initiation of daily PE. Participants without an event during LTS16371 were censored at the end of the study. Kaplan-Meier method was used for the analysis.

8. Percentage of Participants With Major Thromboembolic Events Including Thrombotic Thrombocytopenic Purpura (TTP)

   Time frame: From Baseline up to 36 months

   Major thromboembolic events (e.g., myocardial infarction, cerebrovascular accident, pulmonary embolism, or deep venous thrombosis) were assessed based on Standardized Medical Dictionary for Regulatory Activities (MedDRA) Query (SMQ). Reported major thromboembolic events included TTP recurrences.

9. Number of Major Thromboembolic Events Including Thrombotic Thrombocytopenic Purpura

   Time frame: From Baseline up to 36 months

   Major thromboembolic events (e.g., myocardial infarction, cerebrovascular accident, pulmonary embolism, or deep venous thrombosis) were assessed based on SMQ. Reported major thromboembolic events included TTP recurrences.

10. Time to First Major Thromboembolic Event

    Time frame: From Baseline up to 36 months

    Time to first major thromboembolic event was defined as the duration of time (in days) from Baseline up to first major thromboembolic event in LTS16371. Participants without an event during LTS16371 were censored at the end of the study. Kaplan-Meier method was used for the analysis.

11. Cognitive Function: Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Total Absolute Scores at Baseline, 36 Months Follow-up Visit, and Change From Baseline in RBANS Total Score at 36 Months Follow-up Visit

    Time frame: Baseline, 36 Months follow-up visit

    The RBANS is a 30-minute comprehensive screening test with five individual domains (immediate memory, delayed memory, attention, language, and visuospatial ability) to examine the cognitive mental status of a participant. Scores from all individual domain were aggregated into a total score and thus RBANS total score ranged from 40 to 160, where higher scores reflected better performance.

12. Health-Related Quality of Life (HRQoL): Change From Baseline in Headache Impact Test (HIT-6) Total Scores at Month 12, 24, and 36 Follow-up Visits

    Time frame: Baseline, Month 12, 24, and 36 Follow-up visits

    HIT-6 is an easy to administer assessment that was used as a clinical evaluation of the impact of headache on a participant's QoL in both clinical practice and clinical research. The questionnaire included 6 questions covering the 6 areas of functioning most impacted in headache sufferers including pain, role functioning (the ability to carry out usual activities), social functioning, vitality (energy/ fatigue), cognitive functioning, and psychological/emotional distress. Total HIT-6 scores (sum of all individual questions) ranged from 36 (best outcome) to 78 (worst outcome), where higher scores indicated worse condition.

13. Health-Related Quality of Life: Change From Baseline in 36-Item Short Form Questionnaire (SF-36) Health Survey - Physical Functioning Domain Scores at Month 12, 24, and 36 Follow-up Visits

    Time frame: Baseline, Month 12, 24, and 36 Follow-up visits

    The SF-36 consisted of 36 items that was summarized into 8 domains: physical functioning, social functioning, role functioning/physical, role functioning/emotional, emotional well-being, energy/fatigue, pain, general health and an additional single item covering change in health status. Physical functioning domain scores ranged from 0 (worst value) to 100 (best value), with higher scores reflecting better health status. Change from baseline in physical functioning domain score at months 12, 24, and 36 were reported in this outcome measure.

14. Health-Related Quality of Life: Change From Baseline in 36-Item Short Form Questionnaire Health Survey - Role Functioning/Physical Domain Scores at Month 12, 24, and 36 Follow-up Visits

    Time frame: Baseline, Month 12, 24, and 36 Follow-up visits

    The SF-36 consisted of 36 items that was summarized into 8 domains: physical functioning, social functioning, role functioning/physical, role functioning/emotional, emotional well-being, energy/fatigue, pain, general health and an additional single item covering change in health status. Role Functioning/Physical domain scores ranged from 0 (worst value) to 100 (best value), with higher scores reflecting better health status. Change from baseline in role functioning/physical domain score at months 12, 24, and 36 were reported in this outcome measure.

15. Health-Related Quality of Life: Change From Baseline in 36-Item Short Form Questionnaire Health Survey - Role Functioning/Emotional Domain Scores at Month 12, 24, and 36 Follow-up Visits

    Time frame: Baseline, Month 12, 24, and 36 Follow-up visits

    The SF-36 consisted of 36 items that was summarized into 8 domains: physical functioning, social functioning, role functioning/physical, role functioning/emotional, emotional well-being, energy/fatigue, pain, general health and an additional single item covering change in health status. Role functioning/emotional domain scores ranged from 0 (worst value) to 100 (best value), with higher scores reflecting better health status. Change from baseline in role functioning/emotional domain score at months 12, 24, and 36 were reported in this outcome measure.

16. Health-Related Quality of Life: Change From Baseline in 36-Item Short Form Questionnaire Health Survey - Energy/Fatigue Domain Scores at Month 12, 24, and 36 Follow-up Visits

    Time frame: Baseline, Month 12, 24, and 36 Follow-up visits

    The SF-36 consisted of 36 items that was summarized into 8 domains: physical functioning, social functioning, role functioning/physical, role functioning/emotional, emotional well-being, energy/fatigue, pain, general health and an additional single item covering change in health status. Energy/fatigue domain scores ranged from 0 (worst value) to 100 (best value), with higher scores reflecting better health status. Change from baseline in energy/fatigue domain score at months 12, 24, and 36 were reported in this outcome measure.

17. Health-Related Quality of Life: Change From Baseline in 36-Item Short Form Questionnaire Health Survey - Emotional Well-being Domain Scores at Month 12, 24, and 36 Follow-up Visits

    Time frame: Baseline, Month 12, 24, and 36 Follow-up visits

    The SF-36 consisted of 36 items that was summarized into 8 domains: physical functioning, social functioning, role functioning/physical, role functioning/emotional, emotional well-being, energy/fatigue, pain, general health and an additional single item covering change in health status. Emotional well-being domain scores ranged from 0 (worst value) to 100 (best value), with higher scores reflecting better health status. Change from baseline in emotional well-being domain score at months 12, 24, and 36 were reported in this outcome measure.

18. Health-Related Quality of Life: Change From Baseline in 36-Item Short Form Questionnaire Health Survey - Social Functioning Domain Scores at Month 12, 24, and 36 Follow-up Visits

    Time frame: Baseline, Month 12, 24, and 36 Follow-up visits

    The SF-36 consisted of 36 items that was summarized into 8 domains: physical functioning, social functioning, role functioning/physical, role functioning/emotional, emotional well-being, energy/fatigue, pain, general health and an additional single item covering change in health status. Social functioning domain scores ranged from 0 (worst value) to 100 (best value), with higher scores reflecting better health status. Change from baseline in social functioning domain score at months 12, 24, and 36 were reported in this outcome measure.

19. Health-Related Quality of Life: Change From Baseline in 36-Item Short Form Questionnaire Health Survey - Pain Domain Scores at Month 12, 24, and 36 Follow-up Visits

    Time frame: Baseline, Month 12, 24, and 36 Follow-up visits

    The SF-36 consisted of 36 items that was summarized into 8 domains: physical functioning, social functioning, role functioning/physical, role functioning/emotional, emotional well-being, energy/fatigue, pain, general health and an additional single item covering change in health status. Pain domain scores ranged from 0 (worst value) to 100 (best value), with higher scores reflecting better health status. Change from baseline in pain domain score at months 12, 24, and 36 were reported in this outcome measure.

20. Health-Related Quality of Life: Change From Baseline in 36-Item Short Form Questionnaire Health Survey - General Health Domain Scores at Month 12, 24, and 36 Follow-up Visits

    Time frame: Baseline, Month 12, 24, and 36 Follow-up visits

    The SF-36 consisted of 36 items that was summarized into 8 domains: physical functioning, social functioning, role functioning/physical, role functioning/emotional, emotional well-being, energy/fatigue, pain, general health and an additional single item covering change in health status. General Health domain scores ranged from 0 (worst value) to 100 (best value), with higher scores reflecting better health status. Change from baseline in general health domain score at months 12, 24, and 36 were reported in this outcome measure.

21. Health-Related Quality of Life: Change From Baseline in 36-Item Short Form Questionnaire Health Survey - Change in Health Status Scores at Month 12, 24, and 36 Follow-up Visits

    Time frame: Baseline, Month 12, 24, and 36 Follow-up visits

    The SF-36 consisted of 36 items that was summarized into 8 domains: physical functioning, social functioning, role functioning/physical, role functioning/emotional, emotional well-being, energy/fatigue, pain, general health and an additional single item covering change in health status. Change in health status scores ranged from 0 (worst value) to 100 (best value), with higher scores reflecting better health status. Change from baseline in change in health status score at months 12, 24, and 36 were reported in this outcome measure.

22. Percentage of Participants With Drug-induced Treatment-emergent (TE) Anti-drug Antibodies (ADA) Positive Response

    Time frame: From Baseline up to 36 months

    Drug-induced TE ADA positive was based on the outcome of a tiered assay approach that included a modified ADA (mADA) method to eliminate the effects of pre-existing antibodies (pre-Ab). TE ADA responses reported here included both pre-Ab positive and negative responses. A participant was considered as drug-induced TE ADA positive if post-dose samples were positive, regardless of the status of pre-dose samples in the ADA and modified ADA assay.

23. Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)

    Time frame: From Baseline up to 36 months

    An AE was any untoward medical occurrence in a clinical study participant administered a medicinal product and which did not necessarily had to have a causal relationship with the treatment. An SAE was any untoward medical occurrence that at any dose: resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, was a medically important event.