Document text
COVID-19 Vaccine (BNT162, PF -07302048)
BLA125742/0
Response to 04 Aug 2021FDA IR –Regarding potency assay for determination of IVE by flow cytometry
PFIZER CONFIDENTIAL
Page 1INTRODUCTION
The review team has two questions for y ou regarding the potency assay for determination of
in vitro expression (I VE) by flow cytometry . The review team has requested a response b y
Friday, August 6, 2021.
The following comments pertain to the Report for Co -validation of Test Method
TM100010380 –Determination of the In -vitro Expression of PF -07302048 (BNT162b2
Construct, Drug Product) by Flow Cytometry (VAL100147509).
QUERY1
You reported an overall percent relative standard deviation (%RSD) of in
Table 12- 5 on Page 14 of the report. However, our calculation results in an overall %RSD
using the Mean S1+% data from this table. Please explain how y ou
calculated the overall %RSD for
RESPONSE 1
The overall percent relative standard deviation (%RSD) was calculated using individu al
standard deviation values rather than using the mean S1+ (%) expression results, in error.
The correct %RSD value is equal to using rounded mean S1+
(%) expression values
instead This calculation error has no impact on
the validation since no acceptance
criteria was required as this is a limit test. The validatio
n report has been updated to correct
this error along with 3.2.P.5.3 Validation of Analytical Procedures – Cell-based Flow
Cytometry.
Literature References
None
SUPPORTING DOCUMENTATION
New or Replaced Supporting Documentation
3.2.P.5.3 Validation of Analytical Procedures –Cell-based Flow Cy tometry–replaced
Previously submitted supporting documentation
None
090177e197c05aa9\Approved\Approved On: 06-Aug-2021 15:31 (GMT)
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FDA-CBER-2021-5683-1149502
COVID-19 Vaccine (BNT162, PF -07302048)
BLA125742/0
Response to 04 Aug 2021FDA IR –Regarding potency assay for determination of IVE by flow cytometry
PFIZER CONFIDENTIAL
Page 2QUERY 2
We note that, in Tables 14 -1 and 14- 2 on Page 21 of the report, the mean S1+ (%) results
from compared to the results from . This trend
becomes more , which may indicate some
systematic difference between . Please comment and explain
why you consider repro ducibility to be acceptable given this observation.
RESPONSE 2
090177e197c05aa9\Approved\Approved On: 06-Aug-2021 15:31 (GMT)
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FDA-CBER-2021-5683-1149503
COVID-19 Vaccine (BNT162, PF -07302048)
BLA125742/0
Response to 04 Aug 2021FDA IR –Regarding potency assay for determination of IVE by flow cytometry
PFIZER CONFIDENTIAL
Page 3Literature References
None
SUPPORTING DOCUMENTATION
New or Replaced Supporting Documentation
None
Previously submitted supporting documentation
None
090177e197c05aa9\Approved\Approved On: 06-Aug-2021 15:31 (GMT)
(b) (4)
FDA-CBER-2021-5683-1149504