| Comment Record|
Mr. Guillermo (Bill) Martinez ||
2002-06-04 16:19:11 |
LifeSouth Community Blood Centers, Inc. |
| Comments for FDA General |
1. General Comments
I think NAT enhances the safety of transfusable products by detecting a significant proportion of donors during the viremic phase of primary infection.
The FDA, kit manufacturers, and blood-banking organizations did a good job conducting the large-scale clinical study necessary to demonstrate the efficacy of NAT.
Please accept my comments under four general categories
§ Lack of Universal Availability of NAT
§ Donor Management Issues
§ Gen-Probe’s post approval commitments as stated in the product approval letter of February 27, 2002.
§ Lack of third party information about BLAs
Lack of Universal Availability of NAT
I estimate that fewer than 15 laboratories are currently using the licensed NAT technology, and less than 20 more will have the technical and financial ability to implement the licensed NAT. The limited number of these “NAT” labs, makes it is logistically difficult and expensive to ship, by commercial air carrier, blood donor samples from many areas of the country. Samples that must be shipped by air, because of the distance form the collecting site and the NAT lab, have a significantly higher chance of being lost or delayed whenever connecting flights are required to get them to their intended destination.
I can offer no single answer for making a licensed NAT more universally available, but I think the availability of NAT would be much improved if more than one kit manufacturer was licensed.
Donor Management Issues
What role if any, will NAT have as a confirmatory test?
FDA’s draft guidance of March 13, 2002, advises sites using some, but not all of the licensed components of the technology, to continue their existing INDs. The problem I see with this approach is that the INDs do not offer complete guidance for donor management in the absence of HIV-1 p24, and most blood banks using the licensed NAT reagents have discontinued the use of HIV-1 p24.
The interpretation of results section, from the package insert of the licensed NAT, requires follow-up testing of donors whose samples are positive by pooled testing, whether positive or negative by discriminatory testing, and also negative by serology. I am concerned that the number of donors who are likely to be involved in follow-up (mostly false-positives) will require more resources and expertise than we currently have for this purpose. Please provide guidelines for follow-up testing. Please provide suggestions for what to say to blood donors enrolled in follow-up.
Please provide guidance on invalidating NAT results due to contamination. What would constitute conclusive evidence of contamination?
Please provide re-entry criteria.
Gen-Probe’s Post Approval Commitments
From an outsider’s perspective, Gen-Probe’s post approval commitments seem significant and complex. What will happen if Gen-Probe comes up short on its commitments?
Lack of Third Party Information about BLAs
Our blood center uses the Roche NAT. Roche told us they submitted their BLAs on certain dates, and they are generally reassuring us that they are making good progress towards licensure. My comment is that we have no way of verifying this information, or of knowing if FDA raises significant questions about their BLAs.
We believe that it is not prudent for an organization to make decisions on faith/trust. We could use information from FDA about the status of submitted BLAs.