Buyer Beware: Are You Reducing the Risk of Adventitious Agents in your Raw Materials?

Dr. Barbara J. Potts, Senior Consultant, Potts and Nelson Consulting, joins Pharma IQ ahead of the Ensuring Adventitious Agent Safety in Biologics Conference, taking place 17 to 19 October in Munich, Germany, to discuss the biggest threats to the safety of biologics and which contaminants present the most problems. Potts also shares her insights on common myths surrounding mycoplasma and why they persist, developments in PCR kits and how to ensure the safety of raw materials. To listen to the interview in full go to The Biggest Threats to the Safety of Biologics.

Pharma IQ:
To make a start, what do you consider to be the biggest threat to the safety of biologics?

B Potts:
Probably it’s the lack of knowledge of the risks and I’d say at the senior management level.

Pharma IQ:
And which contaminants present the most problems, either because they’re hardest to mitigate or because they’re more likely to occur?

B Potts: Of course, right now, with the various virus contaminations that have become apparent with GlaxoSmithKline and Merck, with the vaccine and then also with Genzyme, with their product, the viruses seem to be on the forefront, but probably also mycoplasma contaminations. Quite often the mycoplasma contaminations get detected before the product gets put into a vial and put into people, whereas a virus that was in the rotavirus vaccine wasn’t caught until it had already been put into people. So I’d say viruses and mycoplasma probably right now are the biggest risk.

Pharma IQ:
You’ve written a report about the common myths surrounding mycoplasma. Could you just tell us a little bit about that? As you’ve mentioned, what are the most prevalent misconceptions out there and why do they persist?

B Potts:Curious, I’m not a mycoplasmologist; my expertise is in virology and I sort of fell into the mycoplasma problem because of a problem that we had at Genentech when I worked there and it was assumptions that were made about the mycoplasma’s ability to be removed by filtration, I think is the biggest myth out there.

I think we all thought that sterile filtration, which is for bacteria, worked for mycoplasma and it just doesn’t, unless it’s done right. And then the other problem, the other myth, was that all mycoplasma have special growth characteristics that are not present in media; they have no cells. There was this myth that all mycoplasma needed to replicate in the presence of cells. It was a silly myth because to isolate it, you grow it in the absence of cells and when the industry switched over to plant peptones, they picked up a mycoplasma, E. coli plasma, that can grow in sewerage water, anything, and then it showed up in a lot of media cells. And that just sort of blew the myth all to hell.

I think the reason for the myth is that – and I see this in virology, too – is that the biopharm industry is a little separated and segregated from the basic science. They have their own world and you get contaminations in such infrequent times that  it doesn’t, make business sense to have basic scientists on your staff and so then these myths sort of come up that are incongruent with the science. And I’ve seen that both with virology, but specifically with mycoplasmology.

The other thing is probably until recently probably the early 80s was the last time anyone had done any serious mycoplasma research and so these myths they were started back then and then as information grew, it didn’t get into the biopharm field. But I think the fact that filtering… a 0.1 micron filter will remove mycoplasma and that mycoplasma have a special growth characteristic, so the two biggest myths that got the industry into a lot of trouble.

Pharma IQ: Do you think that the industry has done enough to go about correcting those?

B Potts: It’s curious, we had our first workshop, a Parenteral Drug Association workshop, in the US in 2005 and finally got it into proceedings in 2007 and then had two more workshops in 2008 and 2009 and then, we had publications, a series of publications, in biologicals in 2010. So I think in our little group, our task force of about 70 people, 40% international, the other 60% US, we thought everybody just knew that all these myths were myths and so we did a survey.

It’s an audience-response survey where you ask a question and get an immediate answer right there on the spot. And we found is that, you know, about up 50-60% of the audience still believed in the myth. So we were sort of dumbfounded. We realised that, you know, even though there had been this real effort since 2006, 2005, that it hadn’t really gotten into the industry enough. And so we’ve been trying to do is have people give talks, and try to get it out there, but I think we all were a little dumbfounded when we found out that our message hadn’t gotten out there as much as we thought it should have been. So that’s why I think Ensuring Adventitious Agent Safety in Biologics is going to be really good. It’s going to be with a different audience and hopefully we’ll be able to spread the word a little bit more.

Pharma IQ: Great I am looking forward to it too. You said that a lot of regulators don’t really understand what goes on in a company and therefore maybe aren’t well situated to create the guidelines. Do you have any ideas for how this situation can be fixed?

B Potts:The way that the rules are set up for the US regulators versus the European regulators, the US, the FDA is by law really segregated from collaborating with just about anybody unless they have these elaborate creatives they call them. It seems to me they’re more isolated than the European regulators who always have committees that involve a lot of academics and also scientists from industry. So I thought the European regulators seem to be a little more up on the science and it’s just how the governments have chosen to control the interactions between the regulators and the people that they’re regulating.

Pharma IQ: You helped develop one of the first PCR kits, how did that come about? What has been the subsequent response and also what would you have done differently?

B Potts:When I was at Genentech, and I first joined them in 2000 and I had come from an academic environment at the University of Minnesota where I was director for the Center for Xenodiagnostics and this was developing new assays for detecting animal infectious agents that might get into humans if they were going to use primarily porcine tissue in humans. And so I had developed three PCR assays and three peptide-based ELISA assays for three viruses so I was sort of pretty well primed to facilitate an assay for mycoplasma and when I joined Genentech, it was an old project that had sort of lost steam.

I was very fortunate to have a person working for me, Joyce Eldering, who is really excellent in the lab and so I took all of her other responsibilities away from her and just set her up and gave her lots of guidance and help and told her, let’s not reinvent, let’s see what’s out there that we would use and maybe tweak it, to make it useful in a QC setting. For a QC setting, you need to have something that’s fast and fairly easy to do. So actually I have to give Joyce Eldering all the credit for getting the assay going. And basically what she did is, and I’ve added in a few suggestions, too, we took techniques that were in there for mycoplasma PCR from the early 90s, but it was developed in the research field where your sensitivity doesn’t have to be very low. You can have it at a 50, or 100 colony-forming units per mil and that’s good enough. But in the pharmaceutical industry, you have to be down to 1 colony-forming unit per mil. And so the research message had never, you know, taken it down that low, so she was able to tweak it and we were able to add a few things in it from my past experience and we had the assay wrapped up by 2003.

I presented it at Well Characterized meeting in Philadelphia which was 50% US regulators and 50% biopharmaceutical. And I have to admit that at that point, I was surprised at how much resistance there was to switching from a tried and true culture method to a PCR method. There was a lot of resistance, so much so when I came back to Genentech, I told them I didn’t think that that the regulatory agencies were ready for it and so we put the assay to bed for a year and then brought it back up in 2005 and then started to try to get it approved in the US. And one of the strategies that I was encouraged to do by the senior management at Genentech – it was deemed not a patentable assay because we just had tweaked existing methods – was to get the assay out to as many companies as possible, so there would be, you know, a lot of people asking for acceptance for the assay rather than just one company.

So I transferred the assay with Genentech’s help to, I’d say, almost 15 companies. And Roche, at the time, was only a partner at Genentech and not owner of Genentech, and there was Sven Deutschmann from Roche in Germany, picked it up and was able to transfer it to his company really fast and so did David Varnau from Bayer. And they were the two that were the most successful. And the key there was that they had a real strong basic science background, but they were in quality control, so they knew what was needed to move an assay into a quality control setting and to get it approved. And actually, Bayer got approval in Europe and Australia and Japan way before Genentech did because Genentech chose to try to go to the FDA route where we ran into more resistance again it was just lack of understanding and myth about what culture method can and cannot do and PCR, had a bad rep basically from the research methods earlier. And then Roche also got approval in Europe for the assay and it’s about this time Roche acquired Genentech and then they took the method and then turned it into a kit and they changed very little. It’s basically the same assay, so much so that it was approved along with the, we called it the homebrew assay, by the EMA, European Medical Authority.

The kit is really the problem with PCR assays it’s easy to fiddle with it in the lab and you can’t. You have to be for QC assay, you have to have everything be really tightly controlled. So the beauty of having a kit where all the raw materials are quality controlled, and everything is done ahead of time is just the perfect vehicle for a lot release test. So that was sort of the story. At Genentech, we took a different route. We asked for approval before we submitted the validation and so we got approval for using the PCR assay in late 2009 and then I left Genentech in 2009. And sort of some of the steam went out and they are still working on trying to get it validated.

Pharma IQ: You’ve emphasised the need to ensure the safety of raw materials, what do you see as being the biggest challenges in sourcing raw materials and ensuring their purity?

B Potts: In the biopharm field, you know, 99% of the product purification has nothing to do with adventitious agents, but when that 1% comes up, it really bites you hard and that’s the same with the raw materials. There’s a lot of science behind, sourcing raw materials and testing them and so the testing for adventitious agents generally has only been for bacteria and then quite often, you can’t expect a sterile raw material. There’d usually be a bioburden limit on raw materials, such as peptones. But the viruses and the mycoplasma are there and I think the biggest challenge is educating the public that they can’t expect the raw materials to not have those.

It’s like people walk around with bacteria and mycoplasma and viruses on them all the time and they don’t cause any disease and so there’s sort of this unrealistic expectation for raw material purity when it comes to adventitious agents and this was another subgroup that we had with the mycoplasma, the PDA mycoplasma task force was on the peptone sourcing. And so we had a really good group of leaders from the raw material industry and academia, not so much academia, but biopharm group and again we met, during the different workshops, we had different talks and we thought that we’d really educated the public that, it’s buyer beware.

Basically when people buy the raw materials, they have to then take some steps to reduce the risk for viruses and mycoplasma. And then we did again this audience response questionnaire and we found out we hadn’t made any dent in the public. They still thought that the raw materials were responsible, which they are they’re probably responsible for most of the contaminations. But that they felt that it was the raw material vendors’ responsibility and not the customers’ responsibility to control that. So that was another kind of myth that kind of got blown apart. But that one, I think the education is just not there. And we’re sort of stalled on how to get the education out to people because there are some task forces on raw materials now, but 99% of it is not about adventitious agents.

So I’d say that that’s still a standing problem. It’s like with the Circovirus contamination of the GSK and Merck rotavirus vaccines came from porcine pepsin and this virus had been identified in the early 70s and those of us in academia, even myself, we published PTR tests about it, but XJ Meng was the person who really took the lead on that in the late 90s and yet when the contamination came up just – it’s been what, a year and a half, two years ago – the biopharm field and regulators particularly acted like it was something brand new and actually the knowledge of the risk had been out there for a long time. It just somehow hadn’t gotten the decision makers at companies.

I have to emphasise is that the decision makers quite often are senior management who don’t get this education. It doesn’t bubble up to them until it becomes a problem. If the senior management were saying, tell us what your risk is for these raw materials for adventitious agents and what is the plan on mitigating them before you use them, then people would go back and go through journals and open up books and figure it out. But since they’re not being pushed by senior management, mistakes get made. Because 99% of the people in the biopharm field are not adventitious agent experts they’re not needed that often.

Pharma IQ: Do you think it’s this resistance to change from senior management and the lack of people being able to get buy-in from their managers that’s holding the industry back?

B Potts:
I think it’s just the information of the managers at the QC level, where it all lands, most of them are really excellent scientists and have warned and tried to warn, senior management about risks, but for the most part, at least in my field I know in virology and mycoplasmology, the scientists are not Type-A people. They aren’t the kind going around beating drums. They’re good serious scientists and so they’re not politically inclined to raise the red flag to senior management. So I think it has to come from the top down, rather than from the bottom up.

I think senior management needs to have some training and then also I think the regulatory agencies, you know, need to have on-going training and I had proposed actually that we have proficiency panels and I had proposed it for virology, but it could be for mycoplasmology, too, but that proficiency panels, prepared by the international public health agency, be set out to the companies. And, just like you do in clinical testing and human clinical testing, this is done for labs to keep their certification. So it keeps them on their toes, so they aren’t just seeing a contamination once every ten years. They have an opportunity to do some good science right from the get go and then have senior management ask, what were your results? How did you do on that proficiency panel? Or what do we need to do? But senior management needs to have some education on this, I think.

Pharma IQ:
Returning to Ensuring Adventitious Agent Safety in Biologics, what would be your key take-home message from your presentation?

B Potts: On the mycoplasma myth, I think that sterile filtration does not automatically mean that mycoplasma will be removed. One of the task forces of the Parenteral Drug Association, mycoplasma task force, and I’m the chair of that, we have a subgroup on developing a consensus method for removing mycoplasma with a 0.1 micron filter, but it’s, you know, how to validate it and how to control for it, but it’s not a guarantee that it’s a sterile step.

So I think that that’s the big one that has to still be out there, but the other new information that emerged over the last five years is that mycoplasma formed biofilm and a lot of the biofilm, basically they build up and protect themselves so they can protect themselves from heat that would normally inactivate mycoplasma and especially the peptone companies have run into this, where they way they make their peptones, both from animal and plant sources, in this spray ball method is that there are biofilms building up and then, you know, little lumps of mycoplasma are breaking off that are not killed and then they run it through a 0.1 micron filter which is not retaining it, so then you end up with mycoplasma in your media. And so I think that that, especially for the media companies, and then also for biopharm companies that use the media, is a real risk, I think. So biofilm and then the 0.1 micron filter myth are the two big myths.

The other is just to continue to educate the industry on the use of PCR for detection of the mycoplasma in the biopharm setting because, as it is now the assay takes 28 days, so by the time you get a positive result with the culture method, your contaminated product has gone all the way through your recovery line and has contaminated your entire recovery line and, you know, so having an assay that only takes maybe eight hours that you could have as a whole step before you put your product through the recovery line it’s just a really wise business step to take.

So I think if we get the education out there for the method, but then also senior management needs to push for that also to make better business decisions and the more rapid assay you have, the faster decisions you can make and it’s just a better business decision.

Pharma IQ: Thank you so much. We look forward to hearing much more from you at the Ensuring Adventitious Agent Safety in Biologics Conference.

B Potts: Yes, I’m looking forward to it. Hopefully 40% of my task force there from Europe, I’m letting them know about the meeting and hopefully a lot of them will come and especially be able to contribute to the discussion that we’re going to have about what to do after a mycoplasma contamination. I think that hearing the worst stories from companies that have already had it and how they controlled, I think will be really valuable.

Interview conducted by Andrea Charles.


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