Tuesday, October 22, 2013

Unnecessary Testing in cGMP World

In the world of soaring medical costs, we have unnecessary medical tests and procedures sapping precious healthcare dollars.

The thing about these medical tests is that they are necessary for someone under some circumstances, just not for most people under most circumstances.

So is the case in the world of GMP biologics manufacturing. There are
plenty of tests that need to happen to produce a releasable lot. There are in-process tests; there of Certificate of Analysis (CofA) tests.  There are analytical tests you for engineering runs; there are tests you perform on contaminated lots, but not others.

But regardless of what test you are performing, the litmus test for performing the test or analysis is:
Does the result of the test help me make a decision?
Consider the following snippet from a computer program:

   if ( testResult == PASS )
   {
      forwardProcessBatch();
   }
   else
   {
      forwardProcessBatch();
   }

In this case, if I run a test and pass, I get to forward process the batch. If the test fails, I still get to forward process the batch. So if in either case, I get to forward process the batch, why should I bother doing the test? The result of the test does not do anything to serve the outcome!

Another good way to approach the question of whether or not to perform a test is to see if you can write down a plan for what to do with the test result. If you can write down a reasonable plan and stick with the plan prior to getting the test results, then there's a good reason to perform the test; otherwise, you're simply on a fishing expedition and making it up as you go along.

FIO Samples

There exists "For Information Only" samples that are specified into the process.  For example, concentrations of ammonium (NH4+), sodium (Na+), pO2 and pCO2 are measures of cell culture metabolism that are useful for long-term process understanding.  They likely never be used to make a forward-process decision, though they can be used for retrospective justification of discrepancies or as variables during multivariate data analysis.

In my experience, these routine FIO samples are contentious.  On one hand, they serve the purpose of long-term, large-scale process understanding as well as sporadic justification for discrepancies.  On the other hand, if FIO samples get used enough to close discrepancies and release lots, over time the FDA and other agencies will pressure you into making these FIO tests into in-process or lot-release tests.

Defensibility

In the end, your actions in deciding to perform a test need to be defensible.  You need to defend the costs to do the test to management.  You need to defend not doing the test to the FDA.  And your situation may be different than the biologics manufacturer down the street.

That defense ought to rest on whether or not you can do something with the result of the test.


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