Human Gene Therapy: Risk Assessment and Regulatory

Requirements

And Overview of the NIH rDNA Guidelines

EMD 545b

Lecture #10

NIH Guidelines for Research Involving rDNA Molecules

(April, 2002)

NIH Guidelines - April 2002

• NIH - OBA (Office of Biotechnology Activities)

• Outline scope of regulated rDNA work and required containment levels (changes approved by NIH-OBA)

• Applicability– NIH Sponsored Institutions– NIH Supported projects (US & Abroad)

Responsibilities: Institution

• Ensure full conformity with Guidelines

• Establish an IBC

• Appoint a BSO (if necessary)

• Ensure adequate expertise for protocol review (plant, animal, human gene transfer)

• Training (IBC/BSO/PI’s/Lab staff)

• Health Surveillance (BL3/Large scale)

Responsibilities - IBC

• 5 members (2 from community)

• Expertise (rDNA, biosafety, containment, legal)

• Annual report to NIH-OBA (roster/CV’s)

• Assess– Containment level, facilities, procedures– Develop emergency plans, report violations

Responsibilities: Biosafety Officer

• IBC Member

• Inspections

• Report problems to IBC

• Develop emergency plans

• Advise on lab security

Responsibilities: Principal Investigator

• Full compliance with Guidelines

• Can’t start/modify non-exempt work w/out approval

• Report violations w/in 30 days

• Make initial determination of containment

• Instruct/train lab staff

• Supervise safety performance

Section III: Experiments covered by the NIH Guidelines

• Require approval before initiation– III-A: Transfer significant drug-resistant trait

(IBC/RAC review/NIH Director)– III-B: Cloning toxins (IBC/NIH-OBA)– III-C: Human gene transfer (IBC/IRB/FDA

NIH-OBA registration)– III-D: Risk group 2-4 & restricted, defective

virus in cell culture, animals, plants, large scale

Section III: Experiments Covered by the Guidelines

• IBC Notice at time of initiation– III-E-1: < 2/3 viral genome– III-E-3 Production of transgenic rodents – III-E-2: Whole plants

Section III: Exempt Experiments

• III-F-1 through III-F-6– not in organisms/viruses, PCR, known

exchangers, in/out of same host

• Appendix C-1 through C-VI– < 50% viral genome, E.coli, B. subtilis,

S.cerevisiae, Purchase transfer of transgenic rodents, extrachromosomal elements of gm+ organisms

Appendices to NIH Guidelines

• Appendix B: Classification of Etiologic Agents on the Basis of Hazard

• Appendix F: Containment for toxin experiments

• Appendix G: Biosafety containment levels (in vitro experiments)

• Appendix H: Shipment

Appendices to NIH Guidelines

• Appendix K: Large Scale containment

• Appendix M: Human gene transfer

• Appendix P: Plants (biocontainment for rDNA plant experiments)

• Appendix Q: Animal Biosafety containment levels

Human Gene Therapy

• Gene Therapy: Any clinical therapeutic procedure in which genes are intentionally introduced into human somatic cells

• Gene transfer: The deliberate transfer of recombinant DNA, or DNA or RNA derived from rDNA into human subjects. NIH

Notable Quotes

• “Gene therapy has clearly matured from the point of Gee-Whiz to getting down to hard work.

• “Putting genes into people is no longer a worry. We know there are no ill effects. Now we can think of genes as drugs, and that is quite remarkable.”

• Dr. Ronald Crystal, Cornell Medical School

• USA Today, 6/10/99

Notable Quotes

• “The conclusions from these trials are that gene therapy has the potential for treating a broad array of human diseases and that the procedure appears to carry a very low risk of adverse reactions.”

• Dr. W. French Anderson

• Nature, April 30, 1998

September 17, 1999

• 1st reported death attributed to a HGT Protocol: UPENN OTC Trial– subject may have not been properly informed of

risk– not a suitable candidate for the trial

• NIH OBA request for unreported adverse and serious adverse events (11/99)

• 650 previously unreported AE and SAE received by NIH, including unexplained deaths

Lack of Oversight

• Insufficient monitoring once HGT protocols begin

• Beth Israel Hospital (Boston): 7 subjects: 3 unreported deaths and 1 SAE

• Tufts Univ. (Boston): 2 deaths, 1 unexplained, but PI claim unrelated to study

Fox Guarding the Hen House

Rationale for Delayed Reporting

• Reports to FDA (private), not to NIH (public)

• PI decision: “SAE unrelated to study drug”

• Competition between companies

• Financial implications of negative news (stock value)

• Financial conflict of interest (those with shares in parent company)

FDA Response

• FDA request for detailed monitoring plans from institutions and site visits

• Shutdowns– Duke– LA VA Hospitals– Oklahoma State– Univ. Colorado Health Sciences Center– Others

Additional Adverse Events

• Vector associated leukemia - France– 2002- HGT Trials suspended after 2nd case of

leukemia caused by integration of “defective” retroviral vector in host chromosome

Cellular HGT

• Somatic cells– non-reproductive– genetic information not passed to next

generation

• Germ line cells– sperm/egg cells– currently not allowed

Categories of HGT Research

• ex vivo– cells removed from patient– incubated with vector– altered cells returned to patient

• in vivo– direct injection into affected tissues– systemic delivery

HGT Protocols

• 1st U.S. trial 1990: ADA

• 400 trials in past 10 years (3,000+ patients) worldwide

– 62% Cancer– 13% single gene disorders– 9% AIDS

Delivery Vehicles for HGT

• Viruses– murine retroviruses (46%)– adenoviruses (22%)– Other vectors

• adeno-associated virus, vaccinia virus, herpesvirus

• Cationic liposomes (non-viral delivery)

• naked plasmid DNA or RNA (gene guns)

Murine Retroviruses

• Advantages– stable infection– long-term expression– will infect dividing cells only

• Disadvantages– insertional mutagenesis– activate an oncogene/shut off tumor suppressor– recombine with host retrovirus

Murine Retroviruses

• Before 2002 adverse events:• 10+ year experience

– no adverse events (800 patients)– no malignancies– no replication competent retroviruses

– FDA has dropped requirement for lifetime monitoring of patients

Adenoviruses• Advantages

– capacity for large genetic insert– high level of expression– can also infect non-dividing cells– does not integrate into host genome

• Disadvantages– potential recombination with host adenovirus– inflammation, immune response

Adenoviruses

• Last decade– minimal viral shedding from subjects– standard precautions adequate (replace isolation

practices)– consideration of using replication competent

vectors with adequate isolation and monitoring of subjects

Liposomal Vectors

• Positive charged lipid particle– Advantages

• capacity for very large genetic insert

• safe

• ease of mass production

– Disadvantages• low efficiency

• poor specificity

Other Vectors

• Lentiviral vectors (HIV) can infect non-dividing cells

• Vaccinia (HGT vaccines)

• Baculovirus (insect virus)

• Salmonella

• No bounds on imagination of investigators

Oversight of HGT Research

• Food and Drug Administration (FDA)– Sole authority of approval of HGT protocols– Center for Biologics Evaluation & Research

(CBER)• drugs/biological products intended for use in human

subjects

– Investigational New Drug application (IND)• 21 CFR Part 312 Subpart B

Oversight of HGT Research

• Objectives of the FDA– ensure safety/rights of research subjects– ensure scientific quality of clinical

investigations– safeguard public health while promoting novel

therapies

Oversight of HGT Research

• National Institutes of Health (NIH)• applicable to entities that receive NIH funding

– DHHS Office of Human Research Protection (OHRP)

• regulations that protect human subjects/control research risks

– Office of Biotechnology Activities• mandatory registration of HGT Protocols

• national repository

Oversight of HGT Research• NIH

– Recombinant DNA Activities Committee (RAC)

• public notification/participation in discussion

• review 10% of submitted HGT protocols

• NIH Guidelines for Research Involving rDNA, Appendix M

• Points to Consider for Human Gene Therapy

Oversight of HGT Research

• History of NIH RAC Involvement– 1990 - 1996: Approval authority– 1996 - 2000: can recommend RAC review to

FDA– October, 2000: RAC review prior to local

institutional approval to ensure public notification and adequate risk assessment

Local Oversight for HGT

• Institutional Review Board (IRB)– Ensure compliance with FDA and NIH OHRP

requirements to protect human subjects. Federally mandated for any work with humans.

– Informed Consent• risk/benefit evaluation on behalf of subject

• conflict of interest (financial implications)

• ethical issues (false hope)

• review of adverse effects

Local Oversight for HGT

• Institutional Biosafety Committee (IBC)– NIH Requirement (funded locales)– safety– acute/chronic effects– risk to patient, contacts– exclusion criteria– adverse effects (stopping rules)

HGT Protocol Pathway

• PI submission to IRB, IBC and NIH OBA

• OBA/NIH RAC filter: public review?

• RAC comments to IBC, IRB, FDA, OHRP

• IBC/IRB approval

• PI application for FDA IND

• Final FDA approved protocol to NIH OBA, IBC, IRB

• Adverse Effects reported

HGT Risk Assessment

• IBC Review Process– NIH Guidelines, Appendix M– Composition of IBC

• molecular biologists

• infectious disease experts

• immunologists, relevant expertise as needed

• biosafety/containment representation

• occupational health

• community representation

HGT Risk Assessment

• Can your existing IBC efficiently review the HGT protocol?– @ Yale - HGT Subcommittee

• Melanoma Trial– oncologists, hematologists, immunobiologists

• Canavan’s Disease – pediatric neurologists

– neurosurgeons

– ethicists

HGT Risk Assessment

• IBC HGT Review Team should also include:– IRB members– hospital pharmacy– infection control representatives– clinical virologists– legal– ethicists

HGT Risk Assessment

• IBC Questions to the PI:– why is disease a good candidate for HGT?– objective/quantitative disease measures

present?– alternative therapies?– what cells have been targeted for HGT?– describe methods, reagents, full sequence of

inserted DNA, steps to derive construct

HGT Risk Assessment• IBC Questions for the PI:

– preparation of the vector in compliance with FDA 21 CFR Part 211 (Good Manufacturing Practices)?

– clean room facility requirements met?– Trained personnel?– Documented/validated SOP’s and equipment?– QA/QC program in place?– Sterility testing (RCV/adventitious agents)?

HGT Risk Assessment

• IBC Questions for the PI:– adequacy of pre-clinical studies (best animal or

cellular model)?– observed toxicity/efficacy?– chronic effects (time followed after treatment)?– accuracy/efficiency of delivery system?

• affect target cells only (spread to reproductive cells)

• transient of stable infection

HGT Risk Assessment

• IBC Questions to PI:– determination that sequences have been

expressed?– expected benefits or adverse effects– length of follow-up for subjects– post-mortem studies?

HGT Risk Assessment

• IBC Questions for PI:– can DNA spread from subject to contacts or

environment?– required precautions to prevent dissemination?– safety protocols for pharmacy, healthcare staff?– adequacy of clinical facilities?– informed consent/clear communication of risks

to subjects

HGT Risk Assessment

• IRB Considerations:– risk/benefit of protocol– protect subjects from coercion/undue influence– confidentiality/disclosure of information– verification or informed consent process– verify eligibility/withdrawal criteria– ongoing monitoring of subjects– annual renewal of protocol

Adverse Effects

• Serious Adverse Effect (SAE)– FDA

• report immediately if related to study drug

– NIH• ANY SAE reportable immediately to all related

compliance groups

– Annual Data Report• includes SAE’s and AE’s to related compliance

groups

Approval of HGT Protocols

• IRB/IBC Coordination– NIH OBA registration/FDA IND approved

• PI sign-off/acceptance of responsibilities– contingencies outlined on approval letter

• oversight/monitoring– informed consent/eligibility, adverse events,

stopping criteria

HGT Report Card

• “The efficiency of gene transfer and expression in human patients is, however, still disappointingly low.”

• W. French Anderson, Nature, 1998

HGT Report Card

• Not really therapy (treatment)

• Few clinically significant results

• Don’t sell false hope– Human Gene Transfer RESEARCH– SUBJECTS not patients– may or may not gain information

Success Stories

• US ADA 1990 (Anderson)

• French ADA 1999

• Cancer (marker gene) Deisseroth, 1993

• Herpes TK, brain tumor, 1993 (Blaise)

• SHH (activator), heart disease, hair growth (Crystal)

Conclusion

• HGT a promising field

• Human genome project will feed fire

• build on successes, share information

• Goal– cost-effective approach– improved delivery and expression of gene– sustained expression of therapeutic gene

Conclusion

• Responsibility of Regulators:– ensure adequate process of review– approve only sensible, valid projects– ensure the ethical conduct of research– protect human subjects, healthcare workers, and

public

2007 Investigation of Serious Adverse Event

• Death of patient enrolled in study involving an AAV vector (Adeno-Associated Virus)– Focus of NIH OBA Meeting– AAV not a known human pathogen?– Dose?– AAV as cause of event indeterminable

Institutional Approval of HGT Protocols

• Review of location, personnel

• Infection control

• SAE notification

Institutional Approval of HGT Protocols

• Certificate of Analysis to institution from sponsor or designated lab

• GMP Compliance statement from sponsor

• FDA approval letter on file

• Copy of final FDA authorized protocol

Institutional Approval of HGT Protocols

• Data Safety Management Board

• Periodic review of patient safety information

• Report to IRB and IBC

• Annual Renewal of HGT Protocol

• Report changes in protocol

Additional NIH Requirements

• < 20 days post initiation of HGT Protocol– copy of final protocol– NIH Grant # (if applicable)– copy of IRB and IBC approvals– written response to RAC recommendations– date of initiation of trial