The recent Ebola outbreak in western Africa has been something that has captured the world's attention, especially with its high death toll. The question has been how to treat the disease as currently there is no vaccine and the drugs are experimental. On Tuesday, the World Health Organisation met to discuss the ethical implications of using experimental drug treatments on ebola patients. The BBC shared an article earlier this week explaining some of the issues.
If you need a bit of a refresher on how pharmaceuticals are produced, check out an earlier blog I wrote on how pharmaceuticals are produced. There are a lot of regulations to go through and only about 1% of the compounds that make it successfully through the animal trials (such as the ebola drugs) are likely to make it through the human clinical trials.
The other huge challenge with these experimental drugs is that there are limited supplies. Canada has committed 1000 doses of the experimental vaccine.
But why only 1000 doses when so many people are affected? Why can't we just give out more doses? Well this all goes back to how these compounds are produced and the regulations that surround their production.
Early in the testing cycle of pharmaceuticals, you don't need tens of thousands of kg of product, so only about 1-10 kg of product are produced. While clinicians are testing the efficacy of the drug on patients (or animals-depending on phase), process chemists are testing the synthetic pathway. This pathway has to be cost efficient, it has to follow the regulations of good manufacturing practices, and it has to be scalable. Of course, all of this has to be safe. What works on a research lab bench is not always safe or practical on the large scale of production in the pharmaceutical industry.
Finding a drug/vaccine, making sure it works, making sure it works in human trials are only part of the testing that happens. The synthesis is also important. Every synthetic reaction has by products. Not only do you have to test the safety of the product that you want, you also have to test the safety of the by-products of the reaction. You have to demonstrate that they are being removed effectively. This process also needs to be approved by the regulatory bodies. The process is continually optimised during the life time of the drug.
Synthesis also takes are really long time. I remember teaching a postdoc in the lab I did my PhD in how to do a simple esterification reaction. (He was not from a synthetic background.) I remember him being shocked at how long making the compound took, even though it was one step. He figured it would be a couple hours of work and it ended up taking him 2 days to synthesise, isolate, and purify the compound. This is why I found it funny when people figured that the H1N1 flu vaccine circumvented proper testing and regulation when, during the mass outbreak, all of the sudden the vaccine was available for that strain within a couple weeks. It wouldn't have even been physically possible to come up with a new vaccine in two weeks, but let's save influenza for another blog entry in this vaccine series.
But why only 1000 doses when so many people are affected? Why can't we just give out more doses? Well this all goes back to how these compounds are produced and the regulations that surround their production.
Early in the testing cycle of pharmaceuticals, you don't need tens of thousands of kg of product, so only about 1-10 kg of product are produced. While clinicians are testing the efficacy of the drug on patients (or animals-depending on phase), process chemists are testing the synthetic pathway. This pathway has to be cost efficient, it has to follow the regulations of good manufacturing practices, and it has to be scalable. Of course, all of this has to be safe. What works on a research lab bench is not always safe or practical on the large scale of production in the pharmaceutical industry.
Finding a drug/vaccine, making sure it works, making sure it works in human trials are only part of the testing that happens. The synthesis is also important. Every synthetic reaction has by products. Not only do you have to test the safety of the product that you want, you also have to test the safety of the by-products of the reaction. You have to demonstrate that they are being removed effectively. This process also needs to be approved by the regulatory bodies. The process is continually optimised during the life time of the drug.
Synthesis also takes are really long time. I remember teaching a postdoc in the lab I did my PhD in how to do a simple esterification reaction. (He was not from a synthetic background.) I remember him being shocked at how long making the compound took, even though it was one step. He figured it would be a couple hours of work and it ended up taking him 2 days to synthesise, isolate, and purify the compound. This is why I found it funny when people figured that the H1N1 flu vaccine circumvented proper testing and regulation when, during the mass outbreak, all of the sudden the vaccine was available for that strain within a couple weeks. It wouldn't have even been physically possible to come up with a new vaccine in two weeks, but let's save influenza for another blog entry in this vaccine series.
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