 Okay, well thanks for having me today. I think I saw in the, I was billed as an MD-PhD, so while I appreciate the honorary degree, only a PhD and an MS, and I'm basically a bench scientist who does a lot of translational research. So that's my perspective. I'm going to talk a lot about molecular pathways and that sort of thing today. So anyway, let me launch in. I'm going to talk about pharmacogenetics today. And I think probably one of the best compelling stories for pharmacogenetics is this paper right here. It's a case report about a two-year-old boy who went, underwent a tonsillectomy. After his surgery, everything went fine. He was an outpatient. He went home, took codeine to manage the pain, and died a couple of days later of respiratory depression. So didn't really understand why this had happened according to the paper because he had taken the correct amount of pills. There was nothing, no overdose due to the pills. But somebody got smart and genotyped him and found out that he has, instead of two copies of a gene that activates codeine and demorphine called CYP2D6 right here, he has three copies of this gene. So everybody inherits one chromosome from mom and dad. In general, you have two genes. This kid had a duplication on one of his chromosomes that gave him three copies. So he was considered an ultra-rapid metabolizer of codeine and demorphine. And while there's probably about 5% of the U.S. population has this ultra-rapid metabolizer genotype, this probably indicates that this kid had some other confounding issues. It wasn't just that, nonetheless, had he been genotyped, codeine would have been avoided and he probably would still be alive today. On the other side of the coin, people go to the dentist. They get dental work done. They are given codeine to manage the pain when they get home. They go home. Sometimes they take the codeine and it doesn't really have much of an effect. This is because there's a lot of people in the population who are deficient in CYP2D6 and cannot turn codeine into morphine. Codeine has very little analgesic effect. It's really the morphine conversion that is needed for that. So the same gene can cause inefficacy and it can cause severe toxicities. So I work at the NCI, so a lot of my slides have cancer drugs on them, so this is no different. There's a lot of variation in most drug therapies, especially in cancer. But you can see three to 50-fold variation in certain drug therapies and this variability is partially oftentimes attributed to genetics but not always, which leads to the next slide. A lot of people in this room can probably think of more sources of variability, but I'm just going to go through them each here. So drug-specific dose, schedule, the dosage form, how the drug is formulated, et cetera can affect the variability, body size, body composition. Demographic variables such as age, race, sex can affect drug therapies. Physiologic, especially disease states, hepatic and renal function can affect how drugs are handled in the body. Environmental interactions like drug-drug interactions, drug-food interactions, these sorts of things can affect. In genetics is just one of these many variables that will affect drug therapy. So we see this more as a useful tool and not the end-all be-all of determining variability in drug therapies. Now sometimes the genetics is extremely important and sometimes it's not important barely at all. So today I'm going to be primarily talking about cases where the genetics really contributes a lot to the variability and is actually useful for making clinical decisions. There's several types of pharmacogenetic endpoints that we use at the NCI. Like I said, I'm more of a wet bench kind of guy, so I've been handling a lot of the – mining a lot of the samples in our clinical pharmacology program, primarily from cancer patients. And we will notice from time to time that there is an association between a gene SNP and some sort of clinical outcome that we can then go and figure out why this is happening. So here we had a group of patients with prostate cancer treated with dosetaxel. We found that a polymorphism in a gene, CIP1D1, was related to the outcome. So men carrying the wild type, Star-1 SNP, had a double overall survival compared to people carrying the Star-3 SNP. This gene does not metabolize dosetaxel, so we had to do a little investigative work to figure out what was going on. We found out that estradiol is actually metabolized by CIP1B1. CIP1B1 is also up-regulated in almost every single prostate tumor. Those carrying the Star-3 allele turn estradiol into a very reactive metabolite that binds to dosetaxel and adducts it. And this form of dosetaxel is not very potent at all. It also interferes with microtubular polymerization because this reactive form of estradiol will bind to practically everything in the cell and it really likes the sulfhydro groups on tubulin. So we never would have found this interaction without the use of pharmacogenetics. So we use it in a discovery capacity. We're also doing a lot of clinical trials at the NIHs, I'm sure you will know. And so we're often looking at variation in phenotype. So there's a molecular pathway that feeds into a variation in phenotype. So here we were studying an investigative drug that was shown to cause QT prolongation. We knew the drug was handled by a transporter that existed in the heart and basically the transporter functioned so that when the drug got into the heart it was pumped back out. Patients who were not able to pump the drug out as effectively because of a genetic polymorphism are shown here. They had QT prolongation whereas patients who were more effectively able to pump the drug out had barely any at all QT prolongation. So here we're looking at variation in phenotype. We had the molecular pathway sort of characterized. Now both of these feed into clinical trial inclusion and exclusion criteria. You can take people who are responders, non-responders or you're going to get significant toxicities. You could take them out of your population and treat them with other sorts of drugs and subset your population for people where you think the drug is going to be more effective. And all of this of course leads into actual translation of these findings into clinical practice. So today the objectives are to review the molecular and physiological basis for drug-drug and our gene-drug interactions to appreciate the impact on drug therapy to discuss the future of pharmacogenetics and drug development and treatment. So basically I'm going to sort of give you a bird's eye view of pharmacogenes and what they do. I'm going to talk about how the molecular pathway will alter phenotype which will then alter drug therapy. And then at the very end of the talk the NIH has instituted a pharmacogenetics program where a patient comes into the hospital, they're genotyped and that genotype follows them around the hospital in our computer system. So if a doc wants to give them a drug they will have to put it into this system. The system will flag if there is a genetic issue with administering that particular drug. So I'm going to talk about the drugs that we've flagged as important at the NIH at the end. So just launch in with the types of pharmacogenes. So probably when people think of pharmacogenetics they tend to think of these sorts of interactions where you have phase one metabolism which tends to be just redox reactions that oxidize drugs, sorry the arrow got scooted over there. So here you just have a drug that's oxygenated and it becomes more polar. Now this can have two effects. One it can activate drugs like with codeine but in general it deactivates drugs and makes them more soluble, readily excretable. Phase two metabolism is also the chemical modification of a drug. Here you take a polar R group and add it onto the drug so you have drug, drug R, the R is polar it's more soluble and easier to detoxify the drug. Before I go into the SIPs that I'm going to talk about it's helpful to think about what are the major SIPs that metabolize most of the pharmaceutical armamentarium. In general it's SIP 3A4, 3A family probably metabolizes 40 to 60 percent of the drugs that are available right now. This is an old slide but little has changed in the last 13, 14 year. This gene really does not have very many genetic polymorphisms that are very predictive. So I'm not really going to talk about SIP 3As today, however the next two most frequent metabolizers of drugs SIP 2C9 and SIP 2D6 do have some very important genetic variants that will alter their activity so I'm going to talk about those today. These two metabolizing enzymes tend to be the UGTs. You have these UGTs in the liver that glucuronidate drugs and make them more readily excretible in the bile and urine. Then your sulfal transferases and then a host of others that are more or less important in the major metabolism of multiple drugs. I'm going to talk about TPMT today, even though this is a very small sliver this particular gene is quite important in pharmacology. So I'm going to give you the first example here, SIP 2D6 and Tamoxifen. So I already mentioned CIP 2D6 will activate codeine, SIP 2D6 actually also activates Tamoxifen. When Tamoxifen was developed people were thinking I believe that the NDM or the 4-hydroxy were the major metabolites that were actually active. Relatively recently some studies at Georgetown proved that it was endoxifen. It's really the active compound of Tamoxifen. It's formed through endosmethyl Tamoxifen which I'm going to call NDM and it forms this compound which is 3 to 100 fold more active than Tamoxifen or NDM alum. Also when Tamoxifen was being used people noticed that SSRI actually inhibited the hot flashes that people would experience when they were undergoing Tamoxifen therapy and I don't think people really understood why until recently when they found that really what they were doing was inhibiting the enzyme that formed the active metabolite so you had less active metabolite and less hot flashes due to that. So it's kind of useful to think about how does the population break down in terms of 2D6 genetics. We would expect just to back up that people who were deficient in this would have more endosmethyl Tamoxifen to endoxifen ratio. People who were very rapid would have more endoxifen to NDM. The poor metabolizers who do not form as much of the active metabolite comprise probably about 10% of the population roughly and they're at the top right here. On the bottom right you'll see about another maybe 5 to 10% who are ultra rapid metabolizers. They form a lot of endoxifen and the drug is actually probably more effective in these people especially. When the drug was developed though these two extreme ends of the genetic spectrum here were not the general population. The drug was really developed for people sort of in the middle and the people at the ends unfortunately don't benefit as well for the drug or they have more hot flashes, more toxicity to deal with. So you know this is how the population breaks down. Go ahead and talk about the plasma concentrations of the drugs now. So if you look at the endoxifen to NDM ratio and you take the population, you look at their plasma concentrations, you put it on a normative plot which is sort of the statistical method to figure out what groups of people comprise this population. You'll find four bell shaped curves that are very distinct of endoxifen to NDM ratio. These people on the left end here have little endoxifen to NDM, these have high endoxifen to NDM. So what you would expect then that if CYP2D6 was really an important genetic predictor of endoxifen concentration that you would see this curve enriched for poor metabolizers and this one enriched for rapid metabolizers. And that's exactly what you see. Draw your attention to the right hand side of the table here. The poor metabolizers over here are the major constituents of group one which has low endoxifen. The ultra rapid or extensive metabolizers are those that comprise group four which have high endoxifen. Here's another way to look at the data and I wanted to point something out here. The poor metabolizers tend to cluster low on the endoxifen to NDM ratio whereas the extensive metabolizers are high on it. However, you'll notice how much the data really spread here. There are several extensive metabolizers that look like poor metabolizers. This is because this gene is not a perfect predictor of anything. However, it is still a very useful predictor. So if you look at patients with extensive metabolizing versus poor metabolizing, how long it takes them to have recurrent breast cancer, you'll see this where patients with extensive metabolism are benefiting much more from tomoxifen than patients who are poor metabolizers. So basically, we think that the poor metabolism group here really is not benefiting as much from tomoxifen. They should probably be given another drug such as an aromatase inhibitor or something else whereas people who are extensive metabolizers probably benefit more from tomoxifen than they do from other drugs. So when you think about this issue in terms of how does tomoxifen stack up with one of these aromatase inhibitors, for example, tomoxifen is causing a little bit more recurrence. However, this part of the Kaplan-Meier analysis here is composed of a lot of poor metabolizers who are sort of dragging down the efficacy of tomoxifen. And right now, studies are really trying to compare these two curves to see if taking poor metabolizers out of here and moving them to here will actually improve this curve. And some early data from one of these trials is indicating that poor metabolizers that are switched to anastrosol after two years of tomoxifen experience no increase in breast cancer recurrence. So the poor metabolizers who were switched are actually doing better than they would have done on tomoxifen is really the idea. So I talked about a phase one metabolizing enzyme, C2D6. Now I'm going to switch gears and talk about phase two metabolizing enzymes. And I'll talk about thiopurine methyltransferase and six more captopurine and its analogs. So thiopurine methyltransferase just simply methylates drugs and deactivates them through methylation. Sixth bicarbicaptor purine and its analogs are used to treat ALL, inflammatory bowel disease and autoimmune disorders. They're fairly heavily used in the transplant community as well, especially azothioprine in the transplant community. I'll mention that in a minute. These drugs basically just incorporate cytotoxic thiogwani nucleotides into the DNA which causes the cell to die. However, they also do a second thing. They inhibit de novo purine synthesis. So the cell is not as able to synthesize DNA and divide as it otherwise would be. So they're very good drugs. Sixth bicarbicaptor purine was heavily used in childhood ALL. And some of the initial pharmacogenetic studies actually were very concerned with this drug because this drug can cause severe hemotoxicity in childhood patients, can cause death. So St. Jude was very interested in it and it was heavily developed at St. Jude. So the TP-MT, which basically functions to take azothioprine which is converted into 6MP, right? And then it goes to either one of two fates inhibiting de novo purine synthesis or incorporating it into DNA and leading to cytotoxicity. But before they can do that, it will see a lot of TP-MT in the blood and other tissues where it just gets methylated and inactivated. So when the drug was developed, the dosing was based off of people who were very able to metabolize rcaptopurine through TP-MT and inactivate it. So the metabolism of these rcaptopurine drugs is decreased with polymorphic TP-MT variation by up to 200-fold. So 200-fold is a very large number in any therapy and it has a lot of cytotoxicity in patients who are not able to methylate it and get rid of it. And these are the kids that are really experiencing some very severe toxicity from 6MP. So I'll talk about the SNPs in a second. The rapid metabolizers are resistant to the drug. The slow metabolizers are at risk. So the rapid metabolizers are these wild type individuals who have functionals of TP-MT. They're about 80 to 98 percent of the population depending on which population you're looking at. The intermediate metabolizers, they carry one wild type allele and one allele that's not functional. And they're about 65, they need about 65 percent of the dose. But they have some toxicity, but it's not nearly as severe as this group down here of slow metabolizers who carry two copies of these two TP-MT deficiency alleles. And they require about 10 to 15 percent of the original dose. And if you're talking about kids, these people are also at risk for secondary malignancies. So if you give them these drugs in childhood, they can develop cancers later on because they were just administered too much for what they needed. I've just got some results back from the largest pediatric cohort treated with azothioprine. And the results are very positive. The exact same thing is going on with azothioprine as it is with 6MP. And the results should be published within the next year. So it's not only 6MP that's affected, it's these other drugs as well. And it's not just pediatric patients. It's also adult patients. Oh, by the way, I wanted to mention one other thing. The genetic variation in TP-MT explains 95 percent of these hemotoxicity issues with the 6MP. So all of this information is high level of evidence. I'll talk about levels of evidence in a minute. But it's made it into the package insert of 6MP, at least. And the package insert says substantial dose introductions may be required to avoid the development of life-threatening bone marrow suppression in these patients. Now, I'm not a clinician, but I have heard that there is not a lot of genotyping in these patients going on. And this is something that probably needs to be translated clinically to avoid some of these severe toxicities, especially in children. So I'm going to switch gears again. We'll talk about UGT-1A1. This is also a phase 2 metabolizing enzyme. Very important. It is involved... First, let me talk about the SNPs. These TA repeats in the promoter of UGT-1A1. Normal functioning UGT-1A1 has 6 TA repeats. A gene that carries 7 TA repeats is expressed much less effectively in the liver. And if people carry two copies of this allele called UGT-1A1 star 28, they have a decreased expression in function of UGT-1A1. UGT-1A1 is the primary glucuronidator of bilirubin. So these patients have a slight jaundice phenotype known as Gilbert syndrome. And this is about 10% of the U.S. population has this deficiency. There's some other SNPs also that are predictive. I'm not going to go through them, though. These SNPs explain about 40% of the variability in glucuronidation reactions as a whole. Glucuronidation is absolutely key in arenothekin toxicity. So arenotheking is administered IV. It goes into the blood. These carboxyl esterases cleave certain groups off of arenothekin that turn it into its active metabolite called SN38. SN38 is rapidly glucuronidated by UGT-1A1 and is completely detoxified when that happens. If a patient's unable to glucuronidate their SN38, the drug becomes very toxic and you can see some severe ADRs again. However, this is very dependent on the arenothekin dose. This is really what I wanted to bring up. At high dose, almost 100% of the patients who carry this SNP get severe hemotoxicity. Whereas, you know, a moderate amount of patients with wild type alleles get the hemotoxicity. However, if you go down to 125 megs per meter squared, this SNP no longer really matters at all. So this is a very dose-dependent situation. And so sometimes when we think of pharmacogenetics association, we have to consider other issues other than just the gene. Yeah, let me go ahead. So arenothekin toxicity through glucuronidation reactions is made its way to the package insert of the drug. The package insert, this one says that the glucuronidation of Billy Rubin, such as those with Gilbert syndrome, people with that, will be at a greater risk of myelosuppression. I think the updated one actually does list UGT1A1 star 28 now. Switch gears from phase two metabolizing enzymes to transporters. I'm going to talk about one transporter in particular that's been very highly studied in the past five years and I think is on its way to making it into pharmacogenetics directed therapy. It's this OATP1B1 here. So a patient receives a statin, it goes into the gut, goes through the gut wall into the portal blood. It can be metabolized in the gut wall by CIP3A4 or pumped back into the gut wall by MDR1 and MRP2. Once in the portal blood, it basically needs to see an OATP. OATP1B1 is the primary transporter of simvastatin. There are some other OATPs that are very important. But unless this statin sees an OATP, it does not very effectively get into the liver cell. Once in the liver cell, it's metabolized and eliminated. Some of it makes it into the bloodstream and you have varying levels of AUC exposure in these patients. What happened there? Here's a slightly more complex version of what's going on in the liver cell. There's a SNP in this gene, a single-nucleotide polymorphism SNP in this gene that affects how much statin actually gets into the liver cell. The SNP is what's called a non-synonymous transition. In most people, it's the wild type allele. A position 130 gets changed to a D. And this actually has a great effect on AUC exposure of statins. We knew this back in 2006. A very good paper was published showing that this thing is heavily linked to the AUC of statins. Now, greater exposure to statins can lead to statin-induced myopathies. So in patients carrying the SNP that can't get their statins into the liver cell as well, you worry that they're overexposed and they're going to get a myopathy. Another study was published more recently looking at 500,000 alleles in the genome. I love this study. It shows that only one polymorphism was associated with statin-induced myopathy, and not only was it associated, it was several orders of magnitude over the association threshold, which is denoted by that brownish line there. This SNP is almost in 100% complete linkage, meaning it's co-inherited with that N130D SNP. So this SNP is probably just a passenger that's riding along with the N130D SNP causing overexposure to statins and statin-induced myopathies. This group also took these data into a validation cohort where they had cumulative percentages of myopathy, and they found that, again, they see the same SNP is about 20% of the patients are getting statin-induced myopathy, and about 60% of statin-induced myopathy cases could be attributed to this SNP. So this is a very predictive allele. And the present SNP has a 15% representation in the U.S. population. So this is a very frequent SNP. There's a lot of people getting statins that are probably at risk for myopathy just due to this issue alone. At this point, the FDA has not really weighed in on whether or not we should genotype for this one yet, but I think it's coming soon. And at the NIH, we are genotyping for this. I'm going to talk about targets today as well. So, you know, drugs are designed to bind to something in the body, and, you know, these are drug targets. Most people, when they think of drug targets, think of, you know, you're a mat nibs of the world where it's targeted to a somatic mutation and something like BCR-Able. I'm not only going to talk about that today, because I'm really concerned more with the germline variation, the DNA that mom and dad gave us, not mutations in tumors. There are other types of targets that are subject to germline variation. And I'm going to talk about that instead. So, before I get to the targets, here are two cytochromes P450 that take warfarin and convert it into an inactive form of warfarin. So, these, more hydroxylation through 2C9 and CYP4F2 leads to less active warfarin in the bloodstream. But I'm not going to really focus on the CYP story. I'm going to focus over here. Warfarin is designed to bind the vitamin K-oxidoreductase C1. By doing so, it reduces the amount of reduced vitamin K, which reduced vitamin K is pro clotting function. So, warfarin binds to this target. There's a snip in this target gene, VK or C1, that causes the expression of the gene to go down by many fold. So, if a patient lacks sufficient expression of VK or C1, warfarin will bind it all up and cause bleeding events. Brief aside on CYP4F2, it was fairly recently discovered using a platform I'm going to talk about in a minute called the DMET platform. Here's the association. It's very strong. The FDA has again not weighed in on this one, but I think it's going to be up and coming. So, here's the incidence of warfarin sensitivity. I like this paper a lot, showing basically what causes warfarin sensitivity in the general population. And you can see this sort of red-pink piece of the pie chart and this yellow piece of the pie chart correspond to CYP2C9 and VK or C1. So about 40% of warfarin sensitivity in the general population can be attributed to these polymorphisms alone. Incidentally, the CYP2C9 polymorphism, which metabolizes warfarin, is about 1 to 15% of the U.S. population. VK or C variants are more frequent, especially in Caucasians, about 40% of us carry these SNPs that lower VK or C1, and it's about 12% in African-Americans. If you look in the package insert, you'll find this little table, which gives you a warfarin starting dose based on these two SNPs in... Actually, it's three SNPs in VK or C1 and CYP2C9. There's even a neat little iPhone app that allows you to put this information in and get a warfarin starting dose. It's pretty neat. In this case, if the warfarin was already... Dose was already decided upon based on INRs, then obviously you don't need this information, but it still is useful as a starting dose to decide on a starting dose. Okay, I'm going to switch gears again. So I talked about targets. Now I'm going to talk about genes that have effects that are not necessarily related to the target but are sort of ancillary targets themselves. Okay, so I'll show you what I'm talking about in a second if that doesn't make sense. So you have tumor lysis syndrome. You have cellular breakdown, which spills out a lot of DNA. This DNA is catabolized into a lot of purines. These purines can cause hyperuricemia. This uric acid can precipitate in renal tubules and cause renal failure. So this is known as tumor lysis syndrome. A drug is given to avoid this. Actually, two drugs, alpurinol and raspiricase can be used. Raspiricase here takes uric acid and converts it into a readily excretable form of uric acid called allantoin. Here is the actual reaction up here. When urate is converted into allantoin, it produces a lot of hydrogen peroxide. This hydrogen peroxide is cleared by glucose-6-phosphate dehydrogenase. Now there's a group of people that do not have functional G6PD. They tend to be Mediterranean in origin and it's the same group that cannot eat fava beans, which is why I have the broad bean up here, because the toxin in fava beans will actually cause the exact same thing to happen. They'll get severe hemolysis due to too much hydrogen peroxide. Just an interesting aside, it's thought that this population has this deficiency because they want to produce a lot of peroxide in the bloodstream to combat malaria. It's kind of an interesting idea. So anyway, genotyping for G6PD is a very, very good predictor of G6PD function, and so this is a genetic test as well. And the last type of gene-drug interaction I'm going to talk about are these hypersensitivity reactions, which are becoming increasingly important, I think, in pharmacotherapy. So a drug like abacavir goes into a antigen-presenting cell where it sees one of these major histocompatibility complexes. These MHC proteins are encoded by human leukocyte antigen, which is called HLA. These are the genes in the genome, so I'm going to say HLA referring to these proteins here. The genes for these proteins, anyway. These proteins will bind to your drug, go out and start to amount an immune response to the drug itself, which causes hypersensitivity. And it's a Stevens-Johnson syndrome in general. And here's a kid with Stevens-Johnson. This is really considered... It's starting to be considered malpractice to not genotype for this before you give some certain drugs, especially abacavir. There are similar results with carbamazepine and allopurinol. It's still only recommended by the FDA, but it's still extremely predictive of hypersensitivity reactions. Just a simple genotype test can really tell you who's going to get it and who will not. About 5% of patients get a back of your hypersensitivity. If they have one of these HLA loci, you can have up to 103-fold odds ratio of risk of getting hypersensitivity reactions. It's 100% positive predictive value. If a patient has this genetic background, they're almost certain to get a hypersensitivity. It also has a 97% negative predictive value. If they don't have the SNP, you can be 97% sure that they're not going to get hypersensitivity. Here's a conclusion of one of the seminal papers investigating this. I'm just going to read it. In our population, Australians, withholding abacavir and those with HLAB star 5701 or these other HLA should reduce the prevalence of hypersensitivity from 9 to 2.5% without inappropriately denying abacavir to any patient. I think that's really a very good summation of the power of these HLA genotypes. So, I'm sort of giving you the bird's eye view of all the pharmacogenes that are currently out there and are probably moving towards the translation side. Now I'm going to just briefly mention one of the platforms that we use to actually get the genotypes in these patients. Just talk to you a little bit about it. This chip, it's an array-based technology called DMET, which stands for Drug Metabolizing Enzymes and Transporters. It has 2,000 variants and 235 PKPD genes. So, you can see all of these Phase I enzymes. You'll see the ones that I mentioned in there, the Phase II enzymes. You'll see the ones I mentioned in there. Transporters, you'll see the ones, again, the SLC01B1 is in here. And then these other genes that can have effects on PKPD. So, here's G6PD, for example. Cytodine deaminase, which is important for certain other drugs, et cetera. This chip is actually, it only costs about $500 to do the chip. And if you batch a lot of samples, as we've learned, it actually costs only about $50 a patient. So, it's not some outrageously costly thing to do. However, it does have one major deficiency that we've identified. And that is that it takes three days to actually get data out of this. And that's a fast turnaround time. So, for a lot of these drugs, if you need the information right away, you cannot get it. It's just not possible. This isn't CSI Miami. We can't just genotype something in 15 minutes. So, basically, what we've done at the NIH to combat this issue is we have made a policy where a patient gets admitted and then they get this genotyping test done. The information follows them around so that if a clinical decision has to be made rapidly, that this information is there and available and will be flagged to the clinician who is going to give them the drug. We've based the... So, now I'm talking about our experience with PG testing at NIH. We've sort of used this website called FarmGKB, which is run by a lot of the pharmacogenetics experts in this country. They're all part of a network called PGRN. And they have really curated the pharmacogenetics literature very well. So, if you're interested in this, FarmGKB is an excellent resource for learning more. They've published levels of evidence. So, we have only selected those that have the highest levels of evidence that are available. Published control studies of good quality relating to phenotype and or genotype patients, healthy volunteers, having relevant pharmacokinetic and clinical endpoints. Pretty much everything I'm going to discuss today has that high of a level of evidence. It also has a very high level of clinical relevance. So, even though maybe you have a high level of evidence that a SNP is associated with some outcome, that outcome may not be that clinically important. So, they've also curated the clinical importance of this. And all of these genes I'm about to talk about have a high level of clinical importance as well. So, I'm just going to go through the list, because I think you may see some of your favorite drugs on this list, and keep it short so that I don't keep here for too long, but here we go. Abacavir, I already mentioned this one, HLAB5701. This one is recommended, so if an investigator will get flagged, this says you really need to get this genotype before you can administer abacavir. And even though it says the test as TBD, our laboratory medicine branch actually runs this test all of the time. So, we're currently processing this SNP through that branch. Anybody treated with abacavir. Allopurinol, another drug with hypersensitivity reactions. Same story. It's recommended and can be run through the lab right now. Azathioprine or any of these mercaptopurine drugs. I already mentioned these, so I won't go through the mechanism. This is also a very, very highly strongly recommended SNP to test before administering any of these drugs. And we can actually use the DMET platform to do so. Carbamazepine is another HLA. The FDA recommends testing this in Asian populations. Now, this is an issue here. So, I have a friend, I'm from California, I have a friend whose grandfather was one of the original Japanese immigrants to the United States. He doesn't look at all Asian, but he has a significant part of his genome that is Asian. He wouldn't identify himself as Asian, he would identify himself as a Caucasian. If he was treated with this drug because he wasn't Asian and we decided not to genotype him, then he could potentially experience some severe reaction here. So, we've decided that really looking at a person's self-identified race is not the way to go about this. We really need to actually genotype a SNP or not. So, this one is actually very recommended. The test is again through the laboratory branch. Clopidogrel, Plavix, the poor metabolizers have non-responsiveness to clopidogrel. Hyrodosis may be needed in these patients or there's new, there's new anti-platelet agents out that can be used instead of clopidogrel. This one we consider optional available, but we assume that since the information is already available in the clinician that they will just opt for one of those other anti-platelet agents. Coding, I already mentioned it. We don't use a lot of coding at the NIH. This one still is optional or available. The DMET will give you the information. Fluoroprimidines metabolized by DPYD. Patients with deficiencies of DPYD will have some potentially fatal toxicities. So, this test is recommended and it's already available to the clinician via the DMET chip. Irinterferonone-alpha has an association with an IL-28 beta SNP. This is, one SNP is very predictive of who is going to respond well to this drug and another is predictive of who will not respond well to the drug. We consider this optional or available. We have to go outside of the NIH to lab core to really do this one. Renathekin already mentioned it. DMET chip already test UGT-1A1. So, this one's already being used. Isonizid with NAT2. NAT2 is a phase 2 conjugating enzyme that acetylates isonizid and gets rid of a very reactive intermediate metabolite. If people are slow acetylators, they have a three-fold increase in drug-induced liver injuries. This one is considered optional or available. The DMET tests it. CYP2E1, similar story. It's available. Finitoin, difficult drug to dose. There are some variants in CYP2C9 which affect the toxicity and efficacy. This information will be available for dosing of finitoin. Finitoin also causes some hypersensitivity reactions and there's an HLA that's predictive. So, this one's strongly recommended and the test is done through the laboratory branch. Razburacase, which I already mentioned. G6PD genotyping is already available through DMET. Statins and OATP1B1 mentioned it. The test is available through DMET. Tamoxifen, 2D6, test is available through DMET. Warfarin, same snips, DMET test. And then we have the molecular pathology laboratory who is already doing all of the somatic mutations for these targeted agents. So, just run through the targeted agents and not mention much about them. Tristuzumablopatinib, disatinib and nalatinib. Anatmatinib also affects kit so we have the molecular pathologies test kit for us. Jafitinib or latinib and these others. BRAF inhibitors, EGFR inhibitors, RAT inhibitors, alkylating agents. And that's it. So, those are all the drugs that we have implemented at this point at the NIH and the PG testing arena. So, just a couple of final thoughts. How many drugs have pharmacogenetic markers in the label? Well, at this point there are 114 of these drugs and if you go on to this website at the FDA, you can look at all of these drugs. How many drugs have FDA recommendations that are actually actionable? Seven have boxed warnings where the testing is very important. 29 have indications in usage information and 24 will give you information about the dosage. So, a subset of those are actionable. And the last slide here is just considering the prevalence of use of pharmacogenetically affected drugs. There's about 24 million people. This was in 2008 using drugs that have pharmacogenetic information that's available that you can just genotype them and know what, you know, no more information anyway about what to do, make clinical decisions. There's a lot of people using these drugs. This number is just ever increasing and eventually they think this stuff is really going to be important in clinical medicine. And Doug Fig, my boss, always ends his talk by saying, at one day he envisions a child is born. The child gets a DMET chip-like genetic test and that test can be carried with them through life on a thumb drive and they can go and it's their doctor one day, put it into a database, it'll tell them don't give this drug, do give this drug. That seems to be the way that things are going. And so that's all I have to say and thank you very much. Comments or questions? Yes. Could you paraphrase the question? Yeah. So the question was how do you find out if a patient is at risk for clopidogrel in efficacy? And you can use a few options. The first option is you can send it off to have it genotyped by a private company. There are several private companies out there right now doing this. The test really needs to have I think three different alleles and each one of those alleles can cost a certain amount of money. We found that it's actually cheapest to just have the DMET chip run on people. You can take the blood sample, you can send it to the Coriel Institute, they will give you the information back. The guy named Norman Jerry, the guy we run through, he's doing all the NIH studies. You can send the information back and then make the decision based on that. Yes. Thank you for a great talk. You raised a lot of important issues. I'm sure I see at least one patient with either a slow or rapid metabolizer that's not doing well clinically. There was a Dr. Flockard in private practice who used to do consults. So how can we get a consult in terms of private practice to help us? One is a specific drug, but one is metabolizers slower that might affect many, many drugs and that might be beyond the expertise of a private practice doctor. I know there's some agencies that are springing up that offer pharmacogenetic consulting to clinicians. It's a very new thing. You can Google search it. I know that Doug Figg was approached by one of these agencies. I can't really get the name of it. But we're also at the NIH and I'm sure we can direct you in the right direction. I think my email is up here. If we can't help you, I'm sure we can put you in touch with somebody who can at this point. Those of you who are entrepreneurs, it sounds like that's an opportunity. It is, definitely. I want to reiterate the excellence nature of this program Interestingly enough, just from an historical point of view, the 6MV Discoverer is one of the Nobel Prize and you may be aware of that. But to take that a step further, there have been some recent guidelines that have been published by our national organization suggesting that HLA B5801 profiles be obtained and certain groups of patients who are going to be administered in Alapurano. That happens to be the Ham Chinese and certain Thai subgroups. But getting back to your California story, you wonder how many of these particular groups may be here and vulnerable because this is so important for the Alapurano Hypersensitivity Syndrome. So from bench to bedside, this is recommended for looking at the economics of this as we speak. And for the practicality and bench to bedside we are told that this HLA B5801 is now available commercially. Is this an area that you have studied more than your slides? I'm not an expert on HLAs by any stretch of the imagination. But I do know the Alapurano story and I agree with the sentiment that we really need to genotype everyone. So I'm not sure exactly is there... Did that answer your question? Well, it was a statement. Yeah, so yeah, I think that this needs to be genotyped in clinical practice. It absolutely needs to be done because it's so predictive of who's going to get these toxicities. It's very important. That's true. I looked up what came here. I always look to see if there has been yet a lawsuit from Alpractice about one of these things popping up. Nobody has yet sued anybody in one as far as I can tell from Google for not doing one of these HLA tests. However, I have found you mentioned Alapurano. A woman was misdiagnosed with gout, was given Alapurano, got Stevens Johnson sued and won $6 million. So clearly it is something that needs to be addressed clinically. Well, you'll see it. It's on television very quickly on its matter, I think. Boyers are entrepreneurs too. I have a point. I'm reminded that Marlon Seanaway in response to a congressional question that a hearing made the observation that none of us are purebred. That's definitely true, especially in America. We are very ad-mixed. Yeah, thank you. By the people at St. Jude who came up with the TPMT observation and they talked about genetic excellence. The genetic tests are held to a higher standard than your standard clinical assays just because people want them to be so predictive of everything, although they never really will meet that benchmark. So I think that there is a lot of resistance out there right now to implementing a lot of this stuff because of that issue. Similarly, the CYP-2D6 tamoxifen story has been recently stalled by two published studies that came out at the San Antonio Breast Cancer Suposium showing no relationship between CYP-2D6 and tamoxifen outcome. Now, these two studies were fundamentally flawed. There is an editorial by Mark Retain in Cancer Letters talking about how these two studies both violate a fundamental law of nature, the random sorting of alleles amongst populations. And the reason for this is that these folks genotyped tumors and did not genotype the germline DNA. The tumors get mutated and it's not an accurate reflection of what's going on in the liver, how much endoxifen is actually being formed. So these studies have a lot of impediments to them that are outside the control of a lot of us who are doing the science. I think that our group would be partially interested in it. Doug Price here has come for some moral support. He's a fellow staff scientist in our lab so I think we could probably talk to Doug Figg about that, maybe doing some of those studies. Juan Lertora is the guy that runs the PG program right now at NIH and I think you could definitely approach him and ask he's always interested to talk about this sort of information. Would you comment on the role, the traditional role of pharmacists in protecting patients and how you see that role? Well I mean for this I think pharmacists are not geneticists and I know that very well because I am a geneticist and I have to deal with pharmacists all the time. I think that what needs to really happen here on the pharmacy side is that we need to have some very good curated databases where you can just put in genotype information and the people who are experts in genetics and all the other fields that are needed to understand this information. This database just spits out a clinical decision that should be made rather than having the pharmacists do it all. So in fact at the end of the day one could conceive of a system that doesn't lead to alarm fatigue which happens now a lot in pharmacies. They have a bunch of interaction messages and eventually the pharmacist ignore them. It's going to take a lot of work it seems. I don't know of any but I am more of a cancer researcher so I can't say that there is not. I was actually recently diagnosed with psoriatic arthritis and my doc actually mentioned that to me when I went to him. Oh I'm sorry the question was basically there is secondary malignancies in certain cases and there is a secondary malignancies in certain diseases like arthritis inflammatory bowel disease and the question was do you see secondary malignancies that are related to those diseases I think is basically what you are saying right? Or a genotype that is predisposed so that's more of a risk allele less of a pharmacogenetic allele I could see maybe that if you were treated with azathioprine for inflammatory bowel disease that you might see secondary malignancies in patients with certain variants but the disease alleles I just don't know much about. You raised an important issue in terms of clinical trials and that is you know maybe we should lower the patient population to the people most likely to benefit one example that I see every day is leucosmic and jointing works in a subset of the population it's said ineffective when you look at the whole population are we any closer to using genetics and clinical trials to make those more effective? There are several out there in the literature right now that are finally doing this which is exciting I mean we really needed the prospective side of this now I know that there is some resistance to drug companies to do from drug companies to do these sorts of studies because they want their drug to work in the whole population and want to subset it so often times you'll see these prospective studies already being done on approved drugs I'm not aware of any drugs that are being developed at this point with pharmacogenetics in mind but I also don't work for drug companies so I don't really know for sure I don't think anybody has ever done a study like that I think we primarily assume that a generic and an on label or I'm sorry I forget the name a drug that's produced by a drug company are the same compound so I don't think we ever look at generics versus the drug companies drugs I think that a I think that this is a really important field for the future practice of medicine and b felt very incompetent in being able to use it and it seems to me that revolves around competency rather than knowledge and one of the reasons we were very interested in having a pharmacogenetics talk here is that this one is very very close to the clinic on the bedside and it seems like maybe we ought to do some more of this what do you think I see hands mounting maybe we should do a little bit more but I want to thank you very much thank you very much yeah hi