
Email - 125300 Comment and Question, January 27, 2009 - Menveo

 

 
From:                     Valenti, Elizabeth
Sent:                      Tuesday, January 27, 2009 5:21 PM
To:                         'Webster, Christopher'
Cc:                         Valenti, Elizabeth; Fiore, Cara
Subject:                 125300 Comment and Question

Chris,

CBER has the following comments regarding BLA 125300:

In your submission of January 15, 2009, you provided results generated by --b(4)---------------- to re-assess the accuracy over the entire working range of the pertussis ELISAs.  The pre-specified acceptance criteria for accuracy—that the fold-difference between the measured and nominal concentration be within -b(4)--—was satisfied for the PT and FHA assays over their entire working range.  The pre-specified accuracy for the PRN assay was met at nominal values of ---,   -b(4)-; however, the ratio of the measured value to nominal value was --b(4)-----------------------------------------------  You judged this level of accuracy exhibited at -b(4)----------------- to be acceptable given the assays intended purpose of quantitating antibody titers to PRN for study V59P18 clinical samples.  Nonetheless, you indicated that you intend to temporarily reset the lower limit of quantitation (LLQ) for the PRN assay to be -b(4)--------- pending improvements in the assay’s accuracy in this range and re-establishment of the LLQ at --b(4)--.  You also indicated in this submission that, as a consequence of the upward revision of LLQ for PRN from -b(4)-, you propose to rerun the statistical analyses for PRN that were presented in the interim V59P18 Clinical Study Report using the new LLQ and to include these revised results in the final version of the Clinical Study Report.  CBER concurs with this decision.

CBER supports --b(4)----------------- commitment to conduct further work to improve the accuracy of this assay in the lower range of quantitation and reminds both Novartis and ---b(4)---------------- that, while the PRN assay—as it currently stands—is deemed acceptable for the intended purposes of evaluating clinical samples from Study V59P18, it may not be deemed acceptable for other clinical studies that involve different study populations, different end points, etc.

There was some confusion with my previous email, will the data from the proposed re-analysis of the PRN ELISA be included in the Amendment you are planning to submit next week?

Thank you, Betsy
