Alternative Testing or Testing Alternatives?

Posted: November 5, 2007

page 3 of 4

Heylings had worked extensively on the SIFT model; he already had published on it at the IFSCC in 2000 in Berlin, Germany. He concluded that of the five methodologies that went into the pre-validation study, only three passed ECVAM Phases I and II. And none of them fully met the management team criteria for a Phase III blind study, which made him wonder how good the in vivo data actually was. Now eight years later, ECVAM finally picked two alternative assays. Guess which ones? EPISKIN and EpiDerm--the two reconstituted human epidermal models. My alternative predictive testing, also known as scientific gut-feel, could have predicted that one with a high probability.

On the ECVAM website (http://ecvam.jrc.it/index.htm) you can find a statement on the validity of in vitro tests for skin irritation. I quote: “Of these [EpiDerm and EPISKIN], the EPISKIN method showed evidence of being a reliable and relevant stand-alone test for predicting rabbit skin irritation, when the endpoint is evaluated by MTT reduction, and for being used as a replacement (…) for the Draize skin irritation test.”

Let’s now go back to what Ulmer wrote. He stated that “...ECVAM showed an ability to balance risks, such as public safety, with the benefits of eliminating unnecessary animal testing by stepping in as the first group of government regulators to actually move a segment of the industry toward in vitro testing.” But I am not that sure whether the ability to balance risks is coming at too high a price.

First of all, Episkin is owned by L’Oréal and some other manufacturing companies may not want to give money to the competition. Tough, bad luck; those can still use EpiDerm. Secondly and more importantly, what alternative test methods always do is predict the values obtained with a previous test. The Draize test was a test on rabbit skin to predict the irritancy of chemicals on human skin but was performed on rabbit skin, so what it really told us was rabbit skin irritancy. As you could read in the statement of ECVAM’s Scientific Advisory Committee, the new test alternatives are tests that predict rabbit skin irritancy. Rabbits don’t use cosmetics--now that is what I call an alternative, folks!

Instead of spending all that time, money and effort on finding a replacement for an animal test, should we not calibrate it against true human in vivo skin irritancy data? Heylings already wondered how good the in vivo data actually was and rightly so. Our alternative tests should measure or predict the best and not a surrogate. Is that alternative testing or a testing alternative? Nothing can replace the real thing. Think of breast firming and you know what I mean. ...