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DOW JONES NEWSWIRES
December 17, 2004 3:49 p.m.
IRVINE, Calif. (AP)--A University of California neurobiologist may become the first to treat humans with embryonic stem cells.
Hans Keirstead, who is making paralyzed rats walk again by injecting them with brain cells derived from embryonic stem cells, hopes to apply his therapy to humans by 2006.
" I have been shocked, thrilled and humbled at the progress that I have made," Keirstead, 37, said in an interview in his University of California-Irvine office. " I just want to see one person who is bettered by something that I created."
Keirstead has been turning stem cells into specialized cells that help the brain's signals traverse the spinal cord. Those new cells have repaired damaged rat spines several weeks after they were injured.
For the last two years, he has shown dramatic video footage of walking healed rats to scientific gatherings and during campaign events to promote California's $3 billion bond measure to fund stem cell work, which passed in November.
Keirstead and his colleagues are continuing to experiment with rats to ensure the injected cells do what they're supposed to without any side effects.
" You don't want toenails growing in the brain," he said.
Meanwhile, Keirstead and his corporate sponsor - Menlo Park-based Geron Corp. (GERN) - are designing the initial human experiments, which will test for safety and involve just a handful of volunteers. The volunteers likely will be patients who have been recently injured.
Keirstead's work was at first met by derision and disbelief at the Society of Neuroscience's annual meeting in 2002.
We upset a lot of people," said Dr. Gabriel Nistor, who was the first researcher to join Keirstead's lab five years ago. " No one believed us at first." Keirstead and Nistor were stars at the same gathering in October, and their research will be published next month in a scientific journal.
Kierstead is as close as anyone in the stem cell research world could be to celebrity, and reporters have beaten a well-worn path to Keirstead's lab. The fact that he's wealthy only adds to his growing luster.
Keirstead recently sold a biotech company he co-founded, unrelated to his stem cell work, in a deal that could be worth as much as $8 million.
" We all love Hans - for various reasons," said Karen Miner, whose advocacy organization helps fund Keirstead's work.
Miner and her colleagues at Research for Cure, based in Escalon in California's Central Valley, have contributed $170,000 over the last four years to the Reeve-Irvine Research Center where Keirstead works. The center is named for its founding donor, actor Christopher Reeve, who died in October of complications related to his paralysis.
SG Cowan 5th Annual Global Health Care Conference 2004
The Hilton, Geneva, Switzerland November 16-17th 2004
//www.talkpoint.com/viewer/starthere.asp?pres=108232
Okay. Good afternoon. I want to thank everyone for sticking it out toward the end of the day here. I think you'll be well rewarded with a very interesting presentation from our next company, Geron, who's front and center and certainly leading the charge in a couple of very exciting areas of science - stem cell research and telomerase inhibition and it's, in fact it's on cancer. So it's my pleasure to turn it over to the company's chief executive officer, Tom Okarma. Tom.
DR. OKARMA: Thanks Eric, and thank you for coming today. Like everyone else, I'll be making some forward looking statements so we call your attention to our risk factors in our SEC filings.[Slide 2]
[Slide 3] Let's start with who we are and sort of what the game plan is going forward. Historically it's important to understand that both therapeutics platforms evolved from our original core competence which is telomerase biology. In the case of oncology, telomerase is the pan cancer target against which our products are directed. In contrast, the normal expression of telomerase in human embryonic stem cells enables the scalable production of multiple cell therapy products from that starting material. Our strategy in terms of business development on the oncology side is to build a cancer business by developing and commercializing our inhibitor drugs and our vaccine and by licensing oncolytic virus and diagnostic rights to others. On the embryonic stem cell side, the objective is to build a cell therapy company by first demonstrating in man safety and efficacy of the spinal cord injury product and then co-developing with partners other cell therapy products for heart failure, diabetes, musculoskeletal and neurologic diseases. So today Geron is a therapeutic product development company with our first product, the telomerase vaccine, having finished a very successful Phase I/II at Duke; our second cancer product, the telomerase inhibitor drug, scheduled to enter the clinic in the first quarter of next year; and our first product on the embryonic stem cell side, glial cells for spinal cord injury, scheduled to enter the clinic in ‘06. So let's now dive down a little more deeply, first on the oncology program, and then on some of the embryonic stem cell programs.
I said that our oncology platform is based on telomerase, which remains today the only clinically validated, universal and specific cancer target. [Slide 4] All cancer cells depend upon continued expression of telomerase. [Slide 5] Telomerase enables cellular immortality by maintaining the telomeres or ends of chromosomes. Normal cells erode the chromosome end each time they divide until a critical short length is reached and then the cell goes into apoptosis. Tumor cells escape that by this mechanism I'm about to show you. So telomerase, shown here as a ribonuclear protein, binds to the telomere end and in the presence of nucleotide triphosphates they add the canonical T2AG3 repeats to the end of the single strand three prime overhang. At the end of that reaction the enzyme can either translocate and begin that process again continuously on ad infinitum or it can dissociate and find another telomere. So telomerase is the fountain of youth for cells. It operates by maintaining the length of telomeres. [Slide 6] Now the first program I'll talk about is our telomerase inhibitor drug, which as you might expect, because of the ubiquity of telomerase, is literally active against all major human cancers in vitro and it's safe and effective in xenograft models of a growing list of common human cancers. [Slide 7] The drug is based on this molecule here called GRN 163, which is a 13 mer oligonucleotide that is a specific competitive inhibitor of telomerase. This molecule has no antisense activity whatsoever. It does not activate RNA's H. It utilizes a chemistry that our people actually invented, which is critical to the affinity of the drug for the enzyme. So here is the list of tumor types for which this drug is active in vitro – literally all of the major human tumor types of man and the shorter list, but growing, of efficacy and safety in animal models of human cancer. We of course, since we were the first to clone both genes for the protein and RNA component of telomerase, have solid IP protection for the drug itself, the chemistry we use to make it, the target, and of course, the clinical use. Now the way this drug works is very simple. [Slide 8] Here is the mechanism slide I showed a moment ago. The drug fits right in here at the active site. It has a tm of 70 degrees, that means you almost have to boil it to dissociate the drug from the enzyme complex. It shuts the enzyme down and it prevents it from binding the telomere. [Slide 9] Now the clinical formulation of the compound is called 163L because we learned that by lipidating it, putting in a C16 lipid on the five prime end of the molecule, we dramatically alter it's bioavailability and pharmacokinetic characteristics. This is the drug that will enter the clinic early next year. We've received from Dow, our manufacturer, GMP material for the Phase I/II trial and we're about finished now with the in life phase of our IND enabling studies in primates.
Now the reason we are going with 163L over 163 is shown on the following few slides. [Slide 10] First, in vitro cells that express telomerase of various kinds of cancers, and in general the 163L molecule is anywhere from two to 10 fold more potent at inhibiting telomerase in tumor cells than the parent 163. That increased potency in vitro is also expressed in vivo. [Slide 11] Here we're looking at an animal model of human multiple myeloma and we're comparing a high dose of 163, 125 mgs per kilo per week, versus a lower dose of 163L, 75 mgs per kilo per week. And the data are rather striking. It shows first of all that a lower dose of 163L is much more effective at inhibiting telomerase in these cells in the animals. Moreover, that inhibition is translated into a robust loss of telomeric length. So again, less is better than more of the 163L. This is also true from the perspective of the bioavailability. [Slide 12 ] Here's a different model done in Germany of liver cancer. An aggressive tumor that untreated grows to about four sonometers in about four weeks. The point of this slide is to compare again the high dose of 163 in the squares with a much lower dose of 163L in the green triangle and the inhibition of those two curves is indistinguishable. So again a 70 percent reduced dose of 163L in the animal is as effective as a full dose of 163, whether you're measuring reduced tumor growth as shown here, decreased telomerase activity, or decreased tumor cell proliferation. [Slide 13 ] Now the pharmacokinetics of the compound are also markedly different and better. Here we're looking at the degree of telomerase inhibition after a single IV dose of this drug. So again, a high dose 163 is good inhibition initially, but then it wanes over the course of 8 days, compared to the lower dose of 163L which maintains therapeutic inhibition of telomerase after a single injection for over 8 days. [Slide 14] Now we've done a lot of pharmacokinetic modeling. These are the data from rodents, but we've gone through dogs and through monkeys and the difference between 163 and 163L is rather dramatic in terms of tissue half-life. This is a compound that we think will have a half-life in man of about 13 days in certain tissues - a very long half-life. So we've been able now to model through the monkey studies pharmacokinetics for man which clearly show that we can achieve therapeutic tissue levels of this compound with a single IV dose per week. So going forward we have presented this data at the AACR meeting a few weeks ago in San Francisco. We are extending the data in terms of efficacy by demonstrating other tumor types like lung cancer which succumb to this drug in animals as a single agent. We are also publishing combination studies where we're showing synergy between 163L and Taxol in ovarian cancer where we're actually curing animals. We show synergy between 163L and Melfolan in myeloma and melanoma and synergy with Doxirubicin in hepatocellular carcinoma -- in all of those cases, without extending the toxicity of the established compound. Of course the major upcoming news is the filing of our IND which again is scheduled for first quarter of next year.
Second program, already in the clinic, having finished the Phase I/II at Duke, is our telomerase vaccine. [Slide 15] Now our data as you'll see demonstrates that this platform has strong and we think efficacious activity in prostate cancer. Other academic centers using different platforms, but experimenting on telomerase vaccination are showing activity against renal cancer, breast, colon, lung, melanoma and hematologic cancers. So the point here is that telomerase vaccination is beginning to have a long list of tumor types against which it's active, much like the story with the telomerase inhibitor drug, which all turns on the ubiquity of telomerase in cancer. Now our platform is based on autologous dendritic cells - a platform that we in-licensed from Argos Therapeutics earlier this year and the data I'm now going to show you is a combination study in hormone refractory prostate cancer using the platform we licensed from Argos and our telomerase. [Slide 16] So we studied about 20 patients with advanced hormone refractory metastatic prostate cancer. After determining eligibility and obtaining informed consent, patients were leukapheresed once – and one blood collection provides enough cells for from 12 to 20 individual vaccinations. So it is individual, it is ex vivo, but the process is very efficient and provides enough cells for a long course of therapy. The patients were then randomized into one of two arms - either getting RNA of telomerase, plain telomerase RNA, or a LAMP construct that contains sequences that signal the telomerase RNA to be processed by the lysosome system. The objective was to try with LAMP to induce not only CD8 killer T cells, but also CD4 helper cells which you'll see in a moment.
Patients either got 3 weekly doses or 6 weekly doses depending on which dose schedule they were randomized into. [Slide 17] Let's first look at the results for the low dose group, three weekly injections. Well 11 out of 12 patients responded immunologically. We actually think all 12 did and the one who didn't was a lab failure and there were absolutely no adverse reactions. The data look like the following. Here are the 6 patients who received the TERT RNA and on the top line in yellow you see the CD8 response that is specific to telomerase and in the bottom green panel for each patient you see their CD4 counts. And the simple story is in the gray bar here which is before vaccination, the yellow bar here taken two weeks after the third vaccination, you see the enormous uptick in CD8 cells that are specifically responsive to telomerase, and you see that pretty much across the board except for this subject who didn't respond. In contrast, the CD4 levels are very very low in the TERT group. Now when we looked at the LAMP TERT patients, we also saw very good CD8 killer T cell responses, but now we're getting the CD4 helper response that we know to be critical for actually creating memory T cells in these patients which is the objective for the vaccine. So, no adverse reactions, we think virtually everybody responded, and in the LAMP group, both CD8 and CD4 telomerase specific T cells were generated. [Slide 18] Now the story got interesting when we moved to the high dose group, patients who got 6 vaccinations. Again, absolutely no adverse reactions, but now the levels of T cells that we're building up over time - these are the 6 injections here - in two subjects who got telomerase - this is a very different scale - we're now inducing between 1 and 2 percent of the total T cell pool to be telomerase reactive. No one in the oncology vaccine space has ever gotten levels of T cells that high. This is the kind of level that you see in infectious disease vaccination that results in clearance of the infectious particle. Again, when we looked at LAMP in the high dose group, we saw very good, robust CD8 levels and now robust CD4. Again, these are different scales that are in the low dose group. Most significantly, in the manuscript that's about to be published, these CD8s in the LAMP group have a memory phenotype which is what we want to do when we start moving to the boost strategy.
So what have we done that's useful for the disease? [Slide 19] Well, there are two surrogate clinical responses that we think are noteworthy. First, clearance of circulating tumor cells. This is evidence directly that these cells in the blood are active. So there were 10 patients at the beginning of the study who had elevated levels of prostate cancer cells in their blood measured by an RT PCR assay and 9 out of those 10 reduced or completely cleared circulating tumor cells in a kinetic manner that paralleled the induction and wane of the CD8 T cells against telomerase. So here are two subjects that lost a thousand fold of their circulating tumor cells coincident with the induction of CD8 T cells and as those T cells waned, if you remember the kinetics in the prior slide, the tumor cells come back. [Slide 20] So good evidence of correlation of effect. A more traditional measure of efficacy is PSA doubling time, the time it takes for the PSA to double. In the low dose group we saw no significant effect, but in the high dose group, a highly statistically significant prolongation of the PSA doubling time, from 2.9 months pre-vaccination, to over a hundred during the time the T cells were present in the group that got 6 injections. So, next steps here are, we have started a series of small pilot studies at Duke that are exploring slight modifications to the technology we licensed from Merix, now called Argos – they include the use of [onpac] to reduce T regulatory cells, a boosting strategy to maintain higher levels and longer duration of the anti telomerase T cells and we're also looking at a different tumor type that might be a little faster for approval than prostate cancer. You will also hear of the manuscript that we think will be a milestone in cancer vaccination -- it should come out over the next months -- that describes the study in great detail. We are currently now bringing in house the manufacturing process for the vaccine and are beginning to make it into a closed system. Finally, we will select a CMO who will be the manufacturer of the vaccine on contract to us when we move into our own Phase II study.
Just briefly, the two programs in cancer that are outlicensed. The oncolytic virus which is being developed by Cell Genesys under license from Geron. A paper in Cancer Gene Therapy this summer is a good index of what we expect to see here. [Slide21] First, on the left, a model of prostate cancer in a xenogenaic animal. A single IV injection of this virus which contains a telomerase protein promoter was curative of this prostate cancer model. Secondly, in a model of liver cancer, a dose of the virus is shown here, a maximally tolerated dose of doxirubicin is shown here, and the combination is again, curative. Single injection of the virus. And in both of these studies the only place we found live virus was in the tumor cell, testifying to the specificity and power of the promoter. So we do expect Cell Genesys to put one of these constructs into development over the next few months.
[Slide 22] Lastly, telomerase diagnostics. We do commercialize 12 research kits around the world and our partner for clinical diagnostics is Roche who has developed with us a bladder cancer diagnostic that in a 300 patient study in Europe, had a positive predictive value of 84 percent. That means 84 out of 100 people with telomerase in their urine in fact have bladder cancer. This we expect to be marketed under a CE mark in Europe as early as ‘06.
And of course as I mentioned, we have on the telomerase side of the house a controlling intellectual property estate because we were the creators of this field. It covers all of these programs; there are over 200 patents that are issued around the world protecting telomerase.
Let's segue to the other side of the telomerase coin, where telomerase is now the asset that enables embryonic stem cells to divide and live forever. We've surprised everyone, including ourselves, with the amount of progress that we have made. We've learned how to make 8 different therapeutic cell types, differentiated cells, from our embryonic stem cell lines – all of them have normal in vitro function. Six of them are now in preclinical animal testing. Two of our embryonic lines are fully qualified for human use and our first clinical program will be in spinal cord injury and our IND enabling studies for that IND are currently underway. That is scheduled to enter the clinic in ‘06.
[Slide 24] I can't emphasize enough that the expression of telomerase in embryonic stem cells is one of the key factors that separates this platform from all other stem cells. This enables the--expression of telomerase enables us to create scalable manufacturing banks and as you'll see at the end of this part of the talk, manufacturing differentiated cells from embryonic stem cells is much like monoclonal antibody production or biological drug production because of the scaleability of these cells. It's very different from the old world of cell therapy. Let's look at some of these cell types one by one. [Slide 25] The first one is the oligodendrocyte or glial progenitor that we make over a series of weeks from the starting material, undifferentiated embryonic stem cells.
We are working with an animal model of spinal cord injury. [Slide 26] A rat under anaesthesia is given a reproducible blow to the spine and without any treatment is permanently weakened in terms of its lower extremities. I'll show you a movie in a moment to illustrate where the control animals lie. Animals given fibroblasts are really no better than the controls, but animals that are given within a week human glial cells right into the injury have a statistically significant improvement - this is a logarithmic scale - that is stable. Let me show you now a movie of, first, the control animal about 8 weeks after the injury and then a clip of an, one of the animals in the treatment group, about at the same time after the injury. [Slide 27] So, first, here is the animal with no transplant. It's walking by pulling itself on the front paws; the left lower extremity cannot bear weight at all; the right is weak; and the tail is dragged along the bottom of the cage. You see the scar here where the injury was left. And this animal cannot stand on its hind legs. Right. That's the best the control animals get. In contrast, animals who get – sorry, this is the same film – [Slide 28] animals who get the cells support weight on all four extremities and their tail is held off the cage floor and at the very end you can see the animal can support its weight on its two hind legs – right there. That's a pretty dramatic difference, and that's stable.
So the question is why, what have we done? [Slide 29] So when we – sorry – when we sacrifice the animals and look at the lesion site we see two things. First, new neuron growth, which we can quantify to be very dramatic, right at the site of where we've injected these cells. So the glial cells are trophic, they enable new nerve growth at the site of the injury. Second, they create exuberant myelination. [Slide 30] So here are your control animals with very little myelin; here are the animals that received cells – all these little circles are human myelin surrounding the rat axons which could also quantify in both dorsal and ventral lateral column. So these cells are fundamentally re-engineering the injured site, and in a dramatic example of that, [Slide 31] shown here, first the cartoon illustrates that oligodendrocytes can myelinate multiple axons -- in humans 50, 60, 70. Here's an actual picture from one of the animals receiving the cells. Here's the glial cell and here are multiple axons, of the rat, being myelinated by the same cell. So this illustrates generally what this platform is able to do to injury or chronic disease – fundamentally restore tissue architecture and function. [Slide 32] So we're now at the point where we are in IND enabling studies. We have begun our GMP production of the master cell bank from which this product will be made for clinical testing. We're looking at a protocol in which we take patients with lesions anywhere from T2 to L1 first, who require surgical stabilization, at which time the cells will be injected right into the site of the injury. It's an escalating dose study of up to 2 times 10 the 7th cells. There'll be a control group who refuse to get cells. After we do this a few times and establish safety, we're thinking now about moving up into cervical injuries whose patients are on respirators which means a much more objective endpoint than the validated measures we use from motion, locomotor power and sensation. So this is scheduled to begin in ‘06.
The second cell type behind the glial cell is the cardiomyocyte, heart muscle cells. [Slide 33] They make all of the right proteins to show they are in fact bonafide cardiac cells. [Slide 34] They also respond to drugs which illustrates the second general point here, that not only will these cells restore function of the organ, but they will restore pharmacologic responsiveness of that organ because these new cells have drug receptors. So whether it's a calcium channel blocker, an alpha or beta agonist or a phosphodiesterase inhibitor, these cells have the right receptors and respond appropriately to those drugs. [Slide 35] They have normal electrophysiology, they are all ventricular cells and their ventricular depolarization rate–depolarization is proportional to their contractile rate. That's what a normal cardiomyocyte does. When we put them into animals, [Slide 36] you see exuberant engraftment of the human cells in, in this case the rat, which line up and integrate in terms of the sarcomeric myosin. In our first experiments at Stanford in an infarct model where the animal is given a massive infarct, the human cells are injected right into the left ventricle and a month later we come back and do an animal MRI, these are on mice, and what you see is that the cell–the animals that get the cardiomyocytes have actually a fractional shortening [Slide 37] that is normal for the animal compared to BJ fibroblasts or cells, or animals that get no cells whatsoever. So it's a similar kind of story to the spinal cord injury story. We are restoring functional activity in an injured, in this case, myocardium.
Third cell type are islets. And here, in contrast to our other programs, there is no proof of concept required, because the Edmonton Protocol has already demonstrated that cadaveric islets have some utility in treating Type 1 diabetics when those cells are put into the liver. So we have now in fact derived islet cells from embryonic stem cells. They express glucagon and insulin and C reactive peptide and they express insulin in dose response to glucose as a normal islet would. The animal studies are now in progress at Edmonton and I'm pleased to announce that our early results show dramatic prolongation of the diabetic animal's life and human C reactive peptides in the blood of the animals that received these cells.
[Slide 39] What about graft rejection? Well two, two points. First, we are using, we will use low dose immune suppression because the embryonic stem cells are immune privileged. I'll show you that in a moment. Secondly, we have a permanent way to induce immune tolerance to these cells by the use of another cell type called the hematopoetic cell. [Slide 40] This is a mixed lymphocyte reaction. If we mix two different people's blood together, one responds to the other, that's normal. In contrast, if we put undifferentiated, or even differentiated cell types from embryonic stem cells into an MLR, there's no reactivity. In fact, the undifferentiated cell, if added to an active allo MLR inhibits it. These cells contain the same sort of factors that the blastocyst has which prevents the mother from rejecting the implanting 3 day old embryo. These cell types have retained that property.
[Slide 41] The hematopoetic cells we make from embryonic stem cells at low doses actually create stable chimeras in animals. That enables us to do the following. [Slide 42] For any patient, first, they get the hematopoetic cell which makes them immunologically tolerant to any therapeutic cells made from the same embryonic stem cell line. Because all our lines are pluripotent, we can do this with all of our lines. This has been actually worked out in man at Stanford with bone marrow transplantation and renal allografts.
[Slide 43] We are working in the UK on hepatocytes, not for therapy but for drug discovery. These cells have inducible Phase I/II drug metabolizing enzymes and as such are a novel in vitro way to predict hepatic tox and to quantify hepatic metabolism of drugs. [Slide 44] The scaleability of these cells I referred to earlier. We have a culture system now that is completely defined. There is no serum, there is no conditioned medium, all of the additions are recombinant with master files and we have two qualified ES lines. To demonstrate the scaleability, most master cell banks, including ours, have about 200 vials of cells in the bank. At today's efficiency, if we converted all of them to glial cells for our spinal cord injury, we'd have enough cells for 1.3 million doses – that's 5 times the prevalence of spinal cord injury in the United States.
[Slide 45] Our IP is solid behind us. There are 20 issued patents and over 200 in progress, including composition of matter claims for the differentiated cells we make from our lines.
[Slide 46] So that's the Geron story today, a powerful proprietary product pipeline. We have $130,000,000 in cash, a debt free balance sheet. We are the recipient of I think a nice gift from Prop. 71 in California where we are located, which is a $300 million per year for 10 years program to fund California research in embryonic stem cells which we, I think we will benefit from.
So that's the story of Geron. We've moved from a company steeped in science to a company that's now manufacturing three products: the drug, the vaccine and our first cell type from embryonic stem cells.
Thanks very much.
Geron in der Presse !!!
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