Reanalysis for PK Reason: Gone with the Wind [Bioanalytics]

posted by ElMaestro  – Belgium?, 2020-07-16 21:19 (133 d 23:15 ago) – Posting: # 21726
Views: 2,342

Hi Obi,

» Besides non-BE studies, I also noticed that reanalysis to confirm the presence of the analyte in a pre-dose sample is allowed by some BE assessors. Do you think those group of BE assessors are inconsistent? I ask this because, the same assessors will not accept reanalysis of post-dose samples to correct an irregular PK profile.

What I was enforcing back in my day (roughly 200 million years ago), and what I think it still widely accepted, is not so complicated but perhaps convoluted: PK-repeat analysis may be used as part of a lab investigation, but it still requires a root cause to report a repeat value. A root cause is not a statistical figure but something tangible that proves that the original value is not indicative of the concentration in the sample. Whatever the result of a repeat sample is, that in itself is not a root cause.
Some CROs/labs have elaborate schemes with samples being flagged for repeats if they are out of expectation by some objective or subjective measure, and then three repeats are done, and we enter a decision scheme involving a comparison of the original value with the mean or median of the three repeats in the absence of a root cause. That is not at all universally agreed upon as ideal, I think.

I could be wrong, but...

Best regards,
ElMaestro

No, of course you do not need to audit your CRO if it was inspected in 1968 by the agency of Crabongostan.

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