FDA Approves Embryonic Stem Cell Trial In Humans Biotech company Geron Corp. will conduct a human clinical trial on patients with spinal cord injuries, using a federally approved line of embryonic stem cells. The approval is the first of its kind in the world. Stem cell experts discuss the significance of the decision.
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FDA Approves Embryonic Stem Cell Trial In Humans

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FDA Approves Embryonic Stem Cell Trial In Humans

FDA Approves Embryonic Stem Cell Trial In Humans

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This is Science Friday. I'm Ira Flatow. News today that the FDA - the Food and Drug Administration - has given the green light to the world's first clinical trial of an embryonic stem cell-based therapy in humans. Geron Corporation, based in California, will conduct a safety trial on patients with spinal cord injuries, using a federally approved line of embryonic stem cells. President Bush banned the use of federal money to create new embryonic stem cells after August 2001, but Geron has been conducting their research with their own money and money from investors. And many people now are expecting President Obama to reverse the restrictions on embryonic stem cell research. But before that possible executive order, this is a first step ahead towards stem cell therapy.

So, we're going to start the hour by talking about this very interesting, late-breaking story. And if you'd like to get in on the discussion, our number is 1-800-989-8255, 1-800-989-TALK. And if you're on Twitter, you can reach us, the "at" sign, @SciFri - S-C-I-F-R-I - and in Second Life, you go to Science Friday Island. Let me introduce my guests. Dr. Thomas Okarma is the president and CEO of Geron Corporation. He joins us by phone today. Welcome to Science Friday, Dr. Okarma.

Dr. THOMAS OKARMA (President and CEO, Geron Corporation): Thank you for having me.

FLATOW: You're welcome. Sean Morrison is director of the University of Michigan Center for Stem Cell Biology in Ann Arbor. He joins us also today. Welcome back to Science Friday, Dr. Morrison.

Dr. SEAN MORRISON (Cell and Developmental Biology, Director, Center for Stem Cell Biology, University of Michigan): Thanks, Ira. Nice to talk to you again.

FLATOW: Thank you. Dr. Okarma, tell us about the study - what you're studying here. Dr. OKARMA: Well, one of the cells we've learned how to make from embryonic stem cells is called a glial cell. This is a cell that supports and insulates the nerve fibers in our central nervous system. In spinal cord injury, that is the cell that is destroyed by the inflammation, and that is what causes the blockade of nervous transmission across the site of the injury. We have shown in animal models of spinal cord injury that when we inject these human cells directly into the injured cord, we get permanent regeneration of the injury site that leads to stable return of function in the animal's hind limbs. So, studies like that were compiled in a 22,000-page application to the FDA, filed in the first quarter of last year, seeking permission to take this therapy into patients with acute spinal cord injury. And today, we announced that we have finally gained permission to do that.

FLATOW: And how many patients are we talking about here?

Dr. OKARMA: We've asked permission for up to 10, which we think will be enough patients to demonstrate safety for sure and possibly, some clinical utility. The primary end point of the study is safety, and we are using a very low dose of cells to begin with, but we are using secondary end points that will seek to determine if we improve locomotor function, bladder control or sensation to the skin.

FLATOW: So, this is what - it's called a phase-one study?

Dr. OKARMA: That's correct.

FLATOW: Just to see if it's safe to go ahead to the next phases.

Dr. OKARMA: Well, the primary end point, the designation of the purpose of the study is safety. Exactly. But we are also capturing efficacy endpoints. You see, even though this is a low dose of cells, these are living cells, and after they're injected, they multiply. And they can move through the volume of the lesion. So, even though it's a low dose, there's actual living amplification of the effect after the cells are injected, which is why we are hopeful we actually might see some hints of efficacy.

FLATOW: Dr. Morrison, what's your take on this?

Dr. MORRISON: Well, I think it's a really exciting development. It's obviously a milestone in the field to have the first clinical trials moving forward with embryonic stem cells. I think you have to give Geron a lot of credit for investing enormous resources and, you know, taking a lot chances developing this program. It's not a foregone conclusion that it will work, but if Geron can show that these cells are safe to implant in patients, then I think that will be a really important landmark in itself for the field, because it will really encourage future trials using cells derived from embryonic stem cells.

And if Geron can find any evidence of a therapeutic benefit to the patients, it could really be an important thing to stimulate research in this area. You know, even if these patients never walk again, if they're able to restore some partial restoration of spinal cord function in these patients - for example, restoring bladder function to a subset of patients - that could really have enormous quality of life benefits for the patients, and it would be a huge success.

FLATOW: Dr. Okarma, why did you use embryonic stem cells here?

Dr. OKARMA: Well, embryonic stem cells are nature's master stem cell. We do not have to genetically modify the embryonic stem cell or ask it to do anything other than what it's been programmed naturally to do. So, all of the cells that we make from embryonic stem cells, including heart muscle, liver cells, cartilage, islet cells for diabetes - we are simply utilizing mother nature's genetic tape of how she makes a human body, one cell type at a time. So, the point is, this is a natural process.

The embryonic stem cells have two qualities that make them unique in the world of stem cells. One is that they're immortal. They make an enzyme called telomerase that enables us to numerically expand these cells indefinitely, and the cells don't age in culture or degrade. The second characteristic is that they're pluripotent. They literally can be turned into any cell in the human body. So, they're extraordinarily useful and unique. And another element of the technology is that we can, for the first time, scalably produce the cells, much in the same way that drug companies make pharmaceuticals or biological proteins. So, that is important for quality control of the product, as well as to keep the cost of goods down. So, this is really a platform with profound implications for treating chronic disease.

FLATOW: And do you see, if President Obama does reverse President Bush's ruling, that you'll be helped by this, or would it not make much difference now?

Dr. OKARMA: Well, certainly, it would be a step in the right direction. It would help level the playing field between monies made available for adult stem cells versus embryonic. But if that's all that happens, I'm afraid you're correct that there won't be much impact. So, we have called for the establishment of a presidential commission on stem cell policy for the United States. This would be a board that would be empowered to do two things. First, leverage what has been accomplished by industry and academia using private sources of money, and then second, to devise a blueprint of a plan to specifically repair the eight or 10 problems that are serious and long-lasting that have occurred from eight years under the Bush administration. The panel would be composed of representatives from industry, academia, the FDA, NIH and even the venture capital industry.

FLATOW: Dr. Morrison, how do you feel about this? Do you think that - should we be expecting President Obama to reverse the decision soon?

Dr. MORRISON: Well, I do expect that there'll be an announcement sometime within the next month from the Obama administration reversing the restrictions that the Bush administration placed on embryonic stem cell research funding. I think Tom's idea is an interesting one. You know, over the past eight years, the biomedical research infrastructure in this country has withered under reduced funding and the kinds of research restrictions that were put in place under the Bush administration. And so, it will be important in order to jump start this work in particular to reinvest in the biomedical infrastructure in the country. There's obviously exciting opportunities created by stem cell research, and where that kind of research has particularly been restricted under the Bush administration, what you've seen is a patchwork of regulations arise in the states as the federal government abandoned its traditional leadership role in this area. So...

FLATOW: But we've also seen, you know, work where they've been able to reverse skin cells and turn them back into stem cells, and people were saying, we don't need to do embryonics anymore.

Dr. OKARMA: Well, let's talk about that a little bit. First of all, what spurred that work was the unavailability of funds to do normal embryonic stem cell research. These so-called IPS cells, or induced pluripotent stem cells, are actually abnormal cells. They're mutants. They are being induced to do something that nature did - never intended for them to do. So, taking a skin cell and moving it back in the developmental time frame to give that cell the capacity to differentiate into other cell types is an interesting biological experiment. But we now have evidence from a number of labs that the differentiated cells made from IPS cells are abnormal. Because you really need to do this in a natural way, allowing the master stem cell that nature has created to perform its normal function.

FLATOW: Dr. Morrison, do you agree?

Dr. OKARMA: That science is forcing the cells to go backwards.

Dr. MORRISON: I think IPS - the reprogramming of adult human skin cells to pluripotency - is a very exciting discovery and will certainly be part of the answer, in terms of how stem cell research changes the future of science and medicine. What Geron is proposing to do today with embryonic stem cells is not something that could currently be done with reprogrammed cells, because it's still necessary to use viruses that would pose serious safety hazards. But I do expect that research will continue, that the reprogramming process will be improved, and it remains to be seen which cells are going to be most useful for which applications. And so, the one thing that everybody agrees on is that research would continue with all types of stem cells. And particularly given that embryonic stem cells are ready for clinical use, based on the announcement yesterday, I'm sure that patients with spinal cord injuries appreciate the fact that Geron is going forward with trials of embryonic stem cells now, rather than waiting to use reprogrammed cells later.

FLATOW: Dr. Okarma, I just have about a minute left. But based on your work with mice and the success you had in mice, if it is successful in humans, how much time do you think we'll need to pass before we see anything in your test?

Dr. OKARMA: Well, that depends on exactly what happens in the trial. As Sean rightly said, this is a safety trial first and foremost. But if we do see, in half or so of this small group of patients, durable and real clinical improvement, we might actually change course and petition the agency for a registration trial in that small subset of spinal injured patients, namely complete thoracic, which is what is the - which are - the injury that these first patients will have, rather than wait for the normal development of the therapy to impact cervical patients and patients with incomplete lesions.

FLATOW: All right. Sounds very promising. We'll keep our eyes peeled and our hopes up. Thank you both for taking time to be with us. We've run out of time.

Dr. OKARMA: You're welcome.

FLATOW: You're welcome. Dr. Thomas Okarma, president and CEO of Geron, and Sean Morrison, director of University of Michigan Center for Stem Cell Biology in Ann Arbor. We have to take a break. We'll come back, switch gears and talk about, well, how much research is enough? Stay with us. We'll be right back after this break. I'm Ira Flatow. This is Science Friday from NPR News.

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