I-010974-P-0008

February 27, 2006

U.S. Geological Survey
Upper Midwest Environmental Sciences Center
Attention: William H. Gingerich, Ph.D.
Interim Registration Officer
2630 Fanta Reed Road
La Crosse, WI 54603

Re: Target Animal Safety technical section for Chloramine-T

Dear Dr. Gingerich:

By letter dated May 11, 2005, you submitted information to complete the Target Animal Safety technical section of the Investigational New Animal Drug (INAD) file for Chloramine-T. The drug is proposed for the control of mortality in freshwater-reared salmonids due to bacterial gill disease associated with Flavobacterium spp. and for the control of mortality in walleye due to external columnaris disease associated with Flavobacterium columnare (Flexibacter columnaris). The submission requested our review of a draft Freedom of Information (FOI) Summary section for supplemental target animal safety data in hybrid striped bass and draft label language associated with the two claims stated above.

Based on the information in this submission and the information contained in INAD 004000, INAD 010974, and PMF 005637, the Division of Therapeutic Drugs for Food Animals considers the Target Animal Safety technical section for all freshwater-reared finfish to be complete. This technical section complete letter represents our finding that the laboratory studies essential to determining target animal safety are complete and accepted. We also evaluate target animal safety in our review of other technical sections, particularly the effectiveness and all other information technical sections.

A final decision on the approval of the application will be made when all the data for all technical sections are viewed as a whole and it is determined that:

1) the information contained in and referenced by the application supports approval;
2) the GMP status of each manufacturing facility is current and satisfactory;
3) if a claim for categorical exclusion was made, conditions for the categorical exclusion are still applicable; and
4) there is no new information that would preclude the approval of the application.

In addition, we have the following comments.

Draft Label Comments

1. The Indications for Claim #1 should read, “For the control of mortality in freshwater-reared salmonids due to bacterial gill disease associated with Flavobacterium spp.”
2. The last sentence of the Directions for Use for Claims #1 and #2 should read, “Treatments should be administered once daily on alternate days for a total of three treatments.”
3. The Indications for Claim #2 should read, “For the control of mortality in walleye due to external columnaris disease associated with Flavobacterium columnare (Flexibacter columnaris)”.
4. Comments to the Environmental Safety section of the labeling will be provided after we have completed our review of the Environmental Assessment.

Freedom of Information (FOI) Summary Comments

1. We did not include the study in channel catfish fingerlings as part of the Effectiveness section because this study was not submitted for our review. We note the absence of adverse reactions related to treatment at 10 mg/L and 20 mg/L and considered this as part of the All Other Information (AOI) related to target animal safety. You do not need to resubmit this study as part of a future AOI submission for approval of chloramine-T.

2. The Effectiveness and Target Animal Safety sections of the FOI Summary pertaining to the future approval of chloramine-T for the control of mortality in freshwater-reared salmonids due to bacterial gill disease associated with Flavobacterium spp. and for the control of mortality in walleye due to external columnaris disease associated with Flavobacterium columnare (Flexibacter columnaris) have been revised. A copy of the revised sections of the FOI Summary is enclosed. CVM will prepare the final version of the FOI Summary, and will provide you a copy when the last technical section is complete.

If you submit correspondence relating to this letter, you should reference this letter by date and the principal submission identifier found at the top of this letter. If you have any questions about this letter, please contact me at 301-827-7571 or Dr. Donald Prater, Leader, Aquaculture Drugs Team at 301-827-7567.

Sincerely,

/s/
Joan C. Gotthardt, D.V.M.
Director, Division of Therapeutic
Drugs for Food Animals
Office of New Animal Drug Evaluation
Center for Veterinary Medicine