Guest: Dr. Stephen Shrewsbury
Guest Bio: Dr. Shrewsbury was most recently Senior Vice President, Preclinical & Clinical Development and Chief Medical Officer of AVI BioPharma (now Sarepta Therapeutics). From 2005 until 2009, he held similar roles at Adamas Pharmaceuticals and MAP Pharmaceuticals. While at MAP, Dr. Shrewsbury lead four inhaled drug programs and took two lead candidates (in asthma and migraine) from preclinical stage to Phase III in 18 months. Prior to his experience in biotechnology, Dr. Shrewsbury spent 10 years with Glaxo and Chiron launching notable respiratory programs such as Seretide in Europe and Flovent and Advair in the US. Dr. Shrewsbury received his medical degree from the University of Liverpool, UK and spent 13 years working in the UK National Health Service before entering the pharmaceutical industry.
Dr. Steve Shrewsbury discusses his experience while researching the Ebola Virus with the U.S. Military.
HPR – Health Professional Radio
Neal: Hello and welcome to Health Professional Radio. Thank you so much for listening with us today I’m your host, Neal Howard. The Ebola Virus seems to be a non-stop health care issue. The CDC and other organizations worldwide are reporting that the virus is beginning to spread even more so than we thought in the early days of the outbreak in Western Africa. It has reached the United States, Dallas Atlanta, Spain and other places are reporting instances of the virus. It’s so prominent that there even have been pranksters already claiming that someone that they know has Ebola and does pranks haven’t gone unanswered with full scale investigations. Our guest in studio today, Dr. Stephen Shrewsbury, he’s a DNA gene patch expert. Also the author of “Defy your DNA.” He’s here to talk about the Ebola Virus and how it can spread, how it has spread and how maybe the further spread can be prevented. How are you doing today Steve?
Stephen: I’m doing very well. Thank you Neal.
Neal: As the author of “Defy your DNA”, Ebola was just one of the many diseases that you were working with several pharmaceutical companies and other organizations to develop gene patch defenses against these viruses. Could you explain to us how your book covers how DNA can affect viruses once they’ve already taken hold or how it can prevent them from taking hold in the first place?
S: Well Neal, the book is primarily focused on how we can beat some of the really nasty genetic diseases by manipulating the message that comes from our gene to the rest of the cells. So it’s doesn’t actually alter the gene but by changing the message. Once that blueprint leaves the gene and gets to the rest of the cell, a different message is received and a protein can be made that has been missing so the program that I was working on was on Duchenne Muscular Dystrophy and that’s the one that’s probably been most advanced and it’s very exciting because never before have we been able to replace missing proteins and in this case, the protein is dystrophin which happens to be a large protein and the suggestion is that this technology can replace this protein and there are other diseases also, as you mentioned, far along in development and it’s very exciting. But another branch of these gene patches was actually aimed at blocking the message that comes from viruses and also possibly from bacteria and in the case of viruses, traditional small molecule anti-viral drugs have not been terribly successful. We’re way behind where we were are for instance with antibiotics so there are lots of different antibiotics for defeating bacteria but not many anti-viruses for defeating viruses so they’ve been very tricky. So there are some gene patches that have been developed for these anti-virus. Now the exciting thing is, at my last company, you can actually take a virus and you can actually do a genome sequence on it as you can do it with human beings and you can actually find the exact sequence and then you can build a treatment to it. So in fact we took dengue fever and we took other diseases and within a week, you can build a drug that would will against that. That is amazing.
Neal: You are talking about a gene patch, some type of drug to prevent the message that comes from the virus. That message tells our cells to, I guess, accept it or to replicate it or whatever in order for the virus to grow. So am I correct in that?
S: Yes. So that basically blocking that message will stop the virus dead in its tracks. Now the exciting thing is, as I’ve said, you can develop that treatment in a week. So unfortunately, we are on this planet and there are many, many viruses that currently we’re not exposed to or aren’t harmful to us but as we go along, probably, some of these some viruses will mutate. So for instance in the case of the Ebola, that was really first discovered in 1976, and as you’ve mentioned early on, it has been causing outbreaks in Africa in the last 30 to 40 years but they’ve been very sporadic and they really sort of burn themselves out very quickly and it so disappears back in to the animal host. But there are probably other viruses in Africa, in South America, in North America, in Asia that are currently in animals and are not causing too much harm but if they jumped host and got into humans they possibly could be very harmful. For instance, bird flu and swine flu are both probably viruses circulating in animals. When they get into humans, they have catastrophic consequences. So when that happens, and it will happen again in the future it’s almost inevitable, we need to be ready to develop a treatment for them. And really, gene patches are the ideal treatment to develop rapidly in that scenario because they can be built in a week. Nothing else can be built in that time frame. You can’t get vaccines, you can’t get small molecules drugs but you can build this gene patches and then you could use them potentially to effectively treat some of these new emerging viruses. So even though we’re sort of only in the early days of talking about gene patches potentially for treatment in these lethal diseases. I’m sure in the future they will become a much more important opportunity. In this current Ebola outbreak, you’ve heard of another company called Tekmira based in, very close to where I’m working now in Vancouver there in Burnaby, very close to Vancouver, they are developing (they have gotten) Ebola treatment and they have been working with the FDA and the health care organizations to provide some of their test material for treating Ebola patients.
Neal: Now as far as changing the message in our DNA, if you could pin point the specific strand of DNA in the virus, why not attack the virus rather than have the body reject the virus’ attack? Why not develop something to manipulate the virus’ DNA?
S: I’m no expert on this Neal. The trouble is, viruses mutate fairly frequently and actually if you develop something against a specific part of the virus, if it’s a key component – is that component going to change? Viruses are mutating all the time, as in the case of influenza and unfortunately, you know, our ability to keep up with them is not great so we’ll always be out-paced by mutations and as they mutate you need to be able to then answer very quickly this new mutated version of that virus and that really gene patches are going to be the only way that we could develop quickly enough a treatment to a new mutation.
Neal: Okay so what about when it comes to preventing the disease from taking hold in its animal host? If the virus is mutating and jumps from its animal host to a human host there’s devastation, the villages wiped out, the viruses back now into the jungle. why not begin a campaign of changing the DNA of fruit bats in the area is it because of the mutation or because of the inability to capture these animals in mass. What in your opinion is the reason that that approach hasn’t been a possibility?
Steph: Well that’s a good question Neal, I’m certainly not completely current on tracking the virus down but it’s still, as you point out, rightly believed to be that the reservoir is supposed to be the fruit bats in West Africa but I don’t believe it is categorically been determined, that is the case. And you know, trying to catch the fruit bat population of Africa and vaccinate them – that would be an unimaginable undertaking and I think quite outside the scope of any possibility so you know I just don’t think that’s going to happen. It’s gonna be hard enough to even look after the human population in that part of the world and of course doing that with an effective treatment that is expensive. And even general nursing care and rehydration of fluids and barrier nursing is very, very difficult. So I think there are so many levels of difficulty that trying to get to manipulate the reservoir, the fruit bat, is not realistic.
Neal: So as far of the patch technology, there is nothing in place or even on the experimental side, that could infect, for lack of a better term, one of the fruit bats who in turn gives birth to fruit bats that don’t carry the Ebola virus, that can’t carry the virus because of their gene manipulation. Is that a possibility, and then within time fruit bats will not be able to be carriers of the Ebola virus. I mean is that the same thing that were trying to do to us to make it so that the Ebola virus, although it exists, is unable to affect our physiology. Is that what we are trying to do, we can do that with them as well?
S: Well, several questions there Neal. You’re right in some cases we are trying to manipulate natural hosts to reduce their ability to provide refuge to these pathogens. So for instance, we’re doing that with malaria where we’ve been trying, over the last few generations, and malaria of course is rampant in Africa. It causes a lot more problems than Ebola does. Currently, Ebola’s obviously in the headlines but with Malaria we’ve been, I believe, working to try and sterilize mosquitoes so they can’t breed so they then can’t carry the malaria micro in their gut and then re-inject it back into humans. So we are trying to interrupt this life cycle and many of these microbes, be they, in the case of malaria, it’s actually a small animal – all viruses, they go to a cycle where they go to human host, into an animal or mosquito or insect and then back, you know, it’s a cycle around. We’re trying to interrupt that cycle as you suggested. It’s really a good strategy and I think in some cases we could do that but I think with Ebola we don’t fully understand it yet. It’s a young disease, we’ve only really discovered it in the 1970’s and I don’t think as yet we’ve been able to track down exactly where it resides in the animal reservoirs and what species is carried by, that does not harm and how they harbor it or where they harbor it within their bodies. So I don’t think we know enough about it yet and of course trying to uncover that is the work of a large number of people – epidemiologists and doctors working in Africa, and you know I take my hat off to the amazing work they’ve done over the last few decades but with Ebola only appearing every now and then, it’s been difficult to sort of really study it. Now, is the huge opportunity to study it, sadly, because of this terrible outbreak at the moment and you did mention about numbers and I don’t know if you have seen but the Word Health Organization, the CDC have actually estimated that this has affected eight thousand people so far.
S: By the end of this year, so that’s in two months’ time, it could have affected one point four million people.
N: That is the figure that I’ve used, yeah.
S: That is a staggering thing.
S: You know, to think that is the rate at which it could potentially explode in West Africa. Now that it’s in these cities, it’s really a frightening thought.
N: You’ve been listening to Health professional Radio, I’m your host Neal Howard. We’ve been in studio talking with Dr. Stephen Shrewsbury, author of “Defy your DNA.” We’ve been talking about the Ebola outbreak and how it has affected West Africa, some of the ways that Ebola could be prevented through gene patch therapy. We’ve also been discussing a little bit of Dr. Shrewsbury’s book “Defy your DNA.” It’s been great having you here with us today doctor.
S: Thank you Neal, I’ve enjoyed it.
N: I’m hoping you’ll come back in the future and have another conversation with us.
S: I would be delighted to.