1. Ten Years Longitudinal Follow-up Study of Sickle Cell Disease Patients Treated with Hydroxyurea in Four English Centres 20 th September 2007 Annette Gilmore RN BSc MSc Jo Howard MD, Mark Layton MD, Gavin Cho MD, Inderjeet Dokal MD, George Hughes MD, Nicola Philpott MD, Sally C Davies MD, London, England 1

2. Introduction The Registry was initiated in 1998, as a collaborative effort between 10 European countries, with the aim of addressing the effectiveness and toxicity of Hydroxyurea (HU) therapy in Sickle Cell Disease (SCD). Later developed into the North West London Sector Registry – Clinical Patient Database for all SCD patients attending local hospitals in North West London. UK Data Protection Act Registration [Registration No. Z5730583] REC [Approval - MREC/99/2/4] Patient Informed Consent for research 2

3. Aim To evaluate the long-term effectiveness and toxicity of hydroxyurea treatment for sickle cell disease patients managed in routine clinical care settings

4. Methods Compare the change in various clinical and laboratory variables over time Analysis examined changes from baseline to each of the years 1,2,5,7 and 9 Baseline = data collected for 12 months pre HU Clinical outcomes – annual no. IP days, no. Pain Crisis, ACS and Tx events Incidence of serious adverse events and toxicities Appropriate tests for paired data used (Paired t-tests, Wilcoxen matched pairs test and paired exact test)

5. HU Follow-up Proforma 5

6. Sample Patient Graph 6

7. Patient Cohort 7

8. Patient Characteristics 8

9. Biologic Modifications 1 During HU Therapy 9

10. Biologic Modifications 2 During HU Therapy 10

11. Clinical Outcomes Achieved During HU Therapy 11

12. Cumulative Event Rates During HU Follow-up 12

13. Pregnancy & Leg Ulcer Outcomes During HU Follow-up 13

14. HU Treatment Dosing Regime 14

15. HU Treatment Status at End of the Study Period 15

16. Summary Significant reduction in morbidity maintained over time. Some severe adverse events occurred during treatment- association with HU undetermined. MTD was predominant treatment objective but not always achieved or maintained. Demonstrates problems with long-term cohort follow-up. 16

17. Contact Details Annette Gilmore Central Middlesex Hospital Haematology Department Acton Lane London, NW10 7NS United Kingdom Tel:+44(0)20 8453 2135 Fax:+44(0)20 8965 1115 Email:annette.gilmore@nhs.netannette.gilmore@nhs.net 17