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1 Clinical trials with stem cells Bernard Lo, M.D. February 12, 2009
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2 Questions for class Anyone know someone with Type I diabetes?
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3 Goal of session Design a clinical trial of stem cell transplantation for Type I diabetes that addresses ethical concerns
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4 Rationale for stem cell transplantation Type I diabetes caused by autoimmune destruction of beta cells, loss of insulin Long term complications of Type I diabetes despite insulin therapy
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5 Rationale for stem cell transplantation Shortage of donors for Islet cell transplantation Transplant beta cells Derived from stem cells Direct reprogramming of pancreatic exocrine cells
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Induced pluripotent stem cells (iPS cells)
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8 Ethical issues in any clinical trial 1. Risk / benefit balance Outcomes are uncertain Participants at risk, but not designed to benefit them IRB must approve
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9 Particular concerns about risk Pluripotent Differentiate into unintended cells Integrate into unintended targets In vitro manipulation Reprogramming may go awry
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10 Particular concerns about risk Limited experience in humans Unexpected adverse events Long-term adverse effects in chronic illness Hard to discontinue intervention
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11 Ethical issues in any clinical trial 2. Informed consent “Therapeutic misconception” IRB tend to require longer consent forms
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12 Particular barriers to consent Strong scientific plausibility Hope, expectations
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13 Question 1. Why not let everyone who wants a stem cell transplant get it? Available in some countries
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14 hESC transplants readily available No information on materials, protocols No follow-up No control group Conflict of interest
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15 Questions 2. What are risks of stem cell transplantation?
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16 Risks Might not improve clinical condition Not produce insulin Production without regulation Recurrence of autoimmune destruction Adverse events Tumors, cancer
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17 Questions 3. How should the consent process be improved?
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18 Improving the consent process Assess comprehension of key features of trial Clinical Trials 2008; 5: 517-522
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19 Key features of RCT Different than clinical care Not sure that intervention effective or safe May have serious side effects May be unexpected May not be able to reverse the intervention
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20 Questions 5. Who should be enrolled in Phase 1 trial? Children? Adults?
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21 Selection of participants Children May be more effective early in disease Most to lose if severe adverse events Cannot give informed consent to accept risk Adults
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22 Questions 6. Who should be enrolled in pivotal Phase 3 trial? Children? Adults? Someone who gave research funding?
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23 Questions 7. What should be design of Phase 2-3? Sham transplant? Background care in both arms?
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24 Questions 8. What should be duration of pivotal Phase 3 trial? 9. At close of trial should control arm be offered transplantation? 10. How assess very long-term benefits and risks?
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25 Recommendations for clinical trials 3. Disseminate results even if negative Limits of clinical trials databases Clinical Trials 2008; 5: 517-522
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26 Take home message Give trial a catchy NAME Ethical issues are inherent in clinical trials Investigators, referring clinicians, reviewers, readers need to be aware of ethical issues and how to resolve them
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