Clinical trials are the statistical testing of new drug molecules in human patients to determine safety and effectiveness. You frequently hear about drugs having “promising results after Phase II clinical trials” and you may not know exactly what that means.
First, to be clear, a great deal of development effort goes into a candidate molecule before it ever enters a person. There will have been extensive lab tests, tests in animal models (an animal, such as a rat, which has a condition that mimics the human disease of interest) as well as toxicity tests in animals. In general, perhaps 1 in 1000 molecules makes it all the way to phase 1 trials. In biotech, the ratio is probably higher, but that should give you an idea. And once you enter into clinical trials, the majority (perhaps the great majority) of candidate drugs fail at each phase.
A quick summary is:
- Phase I - is it safe?
- Phase II - does it work?
- Phase III - fully, statistically define the drug
Continue reading ‘What are clinical trials?’
A pretty cool development here for fans of gene therapy. The essence of gene therapy is that if a person is born with a defective copy of some gene you can insert a good copy into a critical set of cells in that person and restore the broken functionality. In this case the researchers injected therapeutic viruses into 12 patients brains and saw therapeutic benefits for parkinsons sufferers.
The reason you use viruses for gene therapy is that a virus has evolved to attach to a cell and inject it’s own genes to force the cell to make copies of the virus. It’s possible to gut the virus and insert your own genes of interest, so when the virus infects a cell, all it does is inject your genes. There’s no replication, no spreading viruses, etc. Gene therapy has had a pretty rocky history though, and not a lot of medical success.
Continue reading ‘Gene therapy for parkinsons has successful phase 1 trial’
I came across a short piece in the New York Times recently that’s worth pointing out. It’s about a particular startup in the Bay Area that’s focused on using metabolic engineering to produce anti-malarial drugs and the next item on their agenda is fuel.
For the layperson, metabolic engineering is a step beyond genetic engineering. Metabolic engineering involves creating a new network of complementary reaction pathways within a cell, essentially creating whole new ways of making biological products. In a big picture sense, metabolic engineering treats the cell as a factory, and adds or optimizes structures within the cell for some design purpose.
Continue reading ‘Metabolic engineering as path to medicine and energy’
I’m a researcher in a pharmaceutical biotechnology company, and I’m concerned by the lack of public understanding about what it is we do. In this article I’ll explain some of the process of pharmaceutical manufacture at a biotechnology company, and how you go from a cell stored in liquid nitrogen to a vial of drug for injection. This is intended to be a readable, layman’s explanation of the process. My perspective is fermentation-centric, so apologies to the areas I can’t fully represent. In a later article I’ll discuss more of the research process, where I am involved. I’m also going to sprinkle the article with links to references that have more detail and explanations of technology or equipment.
The master cell bank
The basic concept in biotech is that you identify a molecule that you want, and the sequence of DNA that could be used to produce that molecule. Then you genetically engineer a cell line (CHO or E. coli) to produce it and come up with the correct bioreactor conditions so that they can grow and produce it. Once you have settled on this combination of cell and DNA you place that “master” cell line in liquid nitrogen for permanent storage. This is your gold standard copy from which all drug production starts. You probably have more than one master cell bank to protect you from things like fire and earthquake, since if you lose the master cell line you will have no FDA certified source of cells to produce your product! That would be bad.
The first step in production is to take some of your master cell bank and carefully grow it up in a bioreactor. The goal here is not to make any product, but just to make some more cells, which can then be frozen as a “working cell bank.” Because the master cell bank is so important you try to avoid accessing it as much as possible. Every now and then you take some master cells and create a new working stock.
Continue reading ‘How biotech drugs are produced’