PPTA FDA West Nile Virus Working Meeting

1
PPTA FDA West Nile VirusWorking Meeting

• April 29, 2003

2
Agenda

• Introduction and Overview
• Risk Assessment 0.5 hrs
• Presentation of worst case WNV challenge to
  plasma therapies.
• Verification Studies 1.5 hrs
• Presentation of individual company research on
  WNV inactivation/clearance studies (Aventis,
  Baxter, Bayer)
• Donor Screening and Surveillance 0.5 hrs
• Presentation on challenges of donor screening for
  WNV and discussion of opportunities to conduct
  surveillance.
• Discussion/Next Steps 0.5 hrs
• Discussion of open questions/issues and upcoming
  BPAC agenda.
• Close of Meeting

3
Point to Consider

• Policy Questions
• What is the threshold of risk for testing for
  this and future agents?
• How will the blood system deal with the economics
  of screening for this and future agents?
• (J. Goodman, 6th Annual FDA and Changing the
  Paradigm for Blood Regulation, New Orleans, LA
  2003)

4
New Paradigm

• Rationale
• Risk and science-based approaches dictate
  measured responses to minimal risks.
• WNV testing would require more refined
  technological advances than in place for HIV and
  HCV.
• No proportionate public health benefit for WNV
  testing.
• WNV testing adds no meaningful margin of safety
  for plasma derivatives.
• Offers an opportunity to get ahead of the curve
  anticipating new threats

5
New Paradigm

• Three Part Approach for Addressing WNV
• Risk Assessment
• Assessment of relevant epidemiologic factors and
  worst case challenge to plasma therapies.
• Verification Studies
• Studies demonstrating efficacy of virus reduction
  with relevant model or target viruses.
• Donor Screening and Surveillance (DSS)
• Continued surveillance of WNV epidemic and
  sentinel parameters for evaluating industry
  actions.
• Uses blood screening as public health sentinel
  system for natural . . . disease.

6
Surveillance

• Focus Areas
• Prevalence
• Monitored and reported by CDC
• Significant changes may require reevaluating risk
  assessment worst case assumptions
• Viremic Titers
• Coordination with other industry sectors will
  allow monitoring via sampling plan
• Significant changes in anticipated titers may
  require reevaluating risk assessment and
  inactivation/removal capacity.

7
Conclusions

• The Model virus concept has proven to be
  predictive!
• Three part approach is comprehensive and
  appropriate for WNV.
• Surveillance will provide a safety net in case
  underlying circumstances change.
• No public demand exists for WNV donor screening
  for plasma derivatives.