"Each of these things is a little tiny thing, but you add them all up and they work, in my opinion," he says.
Wheelwright wants to live as long as he can, and says
a lifespan of 120 years is within reach for most people of the next generation. According to a growing number of health researchers, pharmaceutical executives and futurists, that's not such a crazy idea. Key therapies and technologies such as gene editing, stem cell therapy and 3D bio printing are fundamentally altering modern medicine in ways that could lead to much longer human lifespans and possibly put a century of life well within reach for most people.
“The potential of these treatments is huge,” says Phil Vanek, general manager of cell therapy technologies at GE Healthcare.
The possibility of an extra-long life is striking a cultural chord, even if it's not yet scientific reality. Dr. Craig Venter, one of the United States' leading geneticists, has launched a company and raised $70 million on the prospect of extending life, while venture capitalist Peter Thiel has already declared his intent to celebrate his 120th birthday. The concept of living to 120 even has its own Wikipedia page and nutritional regimen.
Today, the average American lives to be about 79 years old -- an age that Wheelwright expects to exceed by many years. Until recently, the process of tacking on more years through better health has been slow-moving. A person born in 1970 in the U.S. could expect to live to be about 70 years old and one born in 2007 could count on seeing about 78 years.
"When I was in college in the 50s, people died of heart attacks when they were 50 years old -- lots of people," Wheelwright says.
No one says expanding life by 42 more years to 120 will be easy, but experts now say it might be possible within two generations.
“The lifespan is going to continue to increase,” Eytan Abraham, head of cell therapy research at Lonza, says. “I think that's quite clear.”
This isn’t the first time that humanity has harbored grand ambitions to prolong life. Hope flourished in the mid-1990s when genetically-modified food hit the market, the first stem cell was isolated from a human embryo and Dolly the sheep was successfully cloned. Each new technology soon ran up against controversy or scientific limitation, though, and hopes of curing cancer or creating genetically-engineering flawless offspring were tempered by both technical reality and ethical concern.
But experts say this time feels different.
Precision Medicine And Targeted Pharmaceuticals
Back in the mid-'90s, an international effort to map the human genome was underway but incomplete. Scientists released their first draft of the human genome in 2001 and ever since, this fast-growing field has stirred up hope that physicians may soon be able to leverage genetics to cure diseases.
Wheelwright signed up for a genetic analysis through 23andMe at the ripe age of 76. His wife signed up for one, too. When their results came back, he was impressed to learn that he was likely to overreact to a blood thinner called Warfarin and susceptible to an irregular heartbeat. Unfortunately, he had already discovered both of those issues on his own over the course of a long life.
"If I had had that information 10 years earlier, it might have made a difference in my life," he says.
Worldwide, about 7.6 million people die from cancer each year. Since 5 to 10 percent of all the types of cancers that these patients die from are inherited, fixing or modifying DNA could provide a potential cure, or at least a highly-effective treatment.
"Some types of cancer are actually very treatable and even curable today because we understand the genetics of the cancer and we've been able to develop targeted therapies for that type of cancer," Emily Burke, biotechnology advisor at Biotech Primer, said in a presentation during last week’s Interphex convention in New York City.
So far, developing new medicines that act on specific genes or proteins has proven more fruitful than using techniques to directly edit, or replace, genetic defects. Genentech, for example, has already started selling an intravenous drug called Herceptin for patients with breast cancer caused by an overabundance of HER2 genes. The drug blocks receptors in the HER2 gene, preventing them from multiplying into more.
Doctors at the Cancer Genome Institute at Fox Chase Cancer Center in Philadelphia can scan the genetic profile of patient’s tumor for mutations for which a specialized treatment may be available. Others have taken a tumor sample from a cancer patient and implanted that sample into a “mouse avatar” as a way to safely test experimental treatments.
“What you've essentially done is created a personalized mouse model for your particular type of cancer,” Burke says.
Gene Therapy And Gene Editing
Gene editing and gene therapy techniques don’t just act on genes, they physically alter them to fix mutations or replace defective sections. Patients with sickle cell anemia have two defective copies of the hemoglobin gene that prevent them from generating a normal amount of red blood cells.
"Wouldn’t it be great if we could just replace their defective copy of the hemoglobin gene with a new copy?” Burke says.
One way to do this would be to engineer a virus to do what it does best -- infect a cell and in the process insert a flawless copy of the hemoglobin gene. But until about five or six years ago scientists didn’t have a safe viral agent that could transport a gene in this manner without infecting the body. However, the EU approved a viral agent called Glybera in 2012 and last year the FDA granted “breakthrough status” to Celladon’s Mydicar therapy for severe heart failure, which is on track to be approved in 2015.
"I think most people are expecting that within the next few years, we'll see many more on the market not only in Europe, but also in the U.S.," Burke says.
If the idea that a virus can improve health still seems a bit far-fetched, know that viruses aren’t the only solution, though the alternatives have yet to make it through clinical trials and some are experiencing setbacks. Scientists may also use tools such as zinc-finger nucleases or Crispr. Both methods can cut a strand of DNA in two, remove a problematic base pair, and insert a new section, but neither of these methods has passed clinical trials. Sangamo BioSciences in Richmond, California, is currently testing zinc-finger nucleases as a way to interrupt a protein that HIV relies on to attack immune cells. Meanwhile, scientists in China reported a major setback just last week in the first test of Crispr's ability to edit human embryos. Only 28 of 86 embryos in their experiment were successfully spliced.
Cell Therapy
Lately, companies have been branching out to find new ways to use cell therapy to treat cancer and promote recovery from heart attacks and stroke. Though gene therapy and editing provide useful ways to target sections of DNA, the human body is not simply a sum of all its genes. Cell therapy, therefore, inserts new live human cells into a patient to replace or strengthen parts that have been injured or lost – blood transfusions and bone marrow transplants are both forms of cell therapy.
“It's going to become another pillar of the healthcare industry,” Richard Grant, global vice president for cell therapy at Invetech, says.
A team at the University of Pittsburgh has learned to extract cells from the thigh of a patient with urinary incontinence, grow extra muscle cells from the sample in a lab, and insert the new cells back into the patient as an added source of muscular strength to help them to regain control over their bladder.
Vanek at GE Healthcare says that while hopes are high for new forms of cell therapy, companies have yet to figure out how to produce these treatments en masse. “Biologically and clinically, these medicines are having a huge impact,” Vanek says. “The question is -- can we manufacture and distribute them?”
Stem cells are one form of cell therapy that are experiencing a resurgence. These cells have the ability to develop into any other form of cell required in the human body. NeuralStem Inc. is currently completing the second of three phases of clinical trials necessary to earn FDA approval to use stem cells taken from a spinal cord to treat ALS patients, who have suffered a loss of motor neurons in their brains and spinal cords.
Burke estimates that within five years, there will be FDA-approved stem cell therapies that are in use, and she thinks they will be particularly helpful in making new cardiac cells and nerve tissue, since people have a hard time regenerating those on their own.
3-D Bio Printing
No matter what critics have said about the 3-D printing craze that has given the world futuristic high heels and lackluster side dishes, medical researchers are taking it seriously. They see 3-D printing as a way to build healthy tissues or organs from cells, or to design medicines containing precise dosages or personalized devices that work best for a specific patient.
On Wednesday, a team of doctors from the University of Michigan’s C.S. Mott Children’s Hospital announced that a baby named Kaiba Gionfriddo, who once suffered from a fatal respiratory condition that caused his windpipe to periodically collapse, is doing well, three years after doctors implanted a splint in his trachea that was created by 3-D printing. The team has since printed and implanted tracheal splints for two more infants, and both are steadily improving after a year or more.
"We were pleased to find that all of our cases so far have proven to improve these patients' lives," Dr. Glenn Green, an associate professor of pediatric otolaryngology at the University of Michigan who led the effort, said in a statement. "The potential of 3-D-printed medical devices to improve outcomes for patients is clear, but we need more data to implement this procedure in medical practice."
The University of Michigan researchers want to pursue FDA approval to bring their tracheal splint-printing skills to mainstream medicine. And this is only one way in which researchers and biotech companies are hoping to use 3-D printing to significantly extend human life. The Armed Forces Institute of Regenerative Medicine, a project of the U.S. Department of Defense, is working to develop a method to print skin to replace the layers lost when a soldier sustains a burn, which cause 10 to 30 percent of deaths on the battlefield.
Burke estimates that “within a year or two,” it could become routine for clinicians to print heart valves, a urethra or blood vessels. She estimates that we’re still decades away from printing fully vascular, complex organs.
The Methuselah Foundation, at least, isn’t waiting around. The organization has created the New Organ Liver Prize – a $1 million award to the first group to bioengineer a liver replacement for a large animal. One way to win would be to print it.
Quality counts
These developments are likely to take decades to break into the world of practical medicine -- through hospitals and consumer drug cabinets. But that doesn’t mean the potential of these transformational therapies feels any less tantalizing to those who are working on the therapies today.
It’s legitimate to question whether it’s prudent to focus limited scientific resources on extending life when researchers could be improving the health of today’s patients. Furthermore, the final decades of life also tend to be some of the most miserable due not only to deteriorating health, but loss of social support and the sense of meaning that many people associate with employment. And what if doctors save a patient from organ failure and heart disease but in turn sentence them to a decades-long struggle with Alzheimer’s disease, for which there is no cure?
“We are going to be extending lifespans but we don't want to do so at the expense of quality of life,” Abraham of Lonza says.
When asked if he would like to live to be 120 years old, Grant of Invetech says, “Only if I can have quality of life to go along with it.”
Vanek at GE Healthcare says even if researchers miss the mark of living until 120, sharing that goal helps to focus the field of biomedical research in a way that will inevitably lead to valuable new treatments for today’s patients.
“I think longevity has that moon shot element. It's big and interesting but I think quality of life is really why we do what we do,” Vanek says. “If you're targeting longevity, and you fall short of it, you're still going to end up improving quality of life.”
And maybe that has really been the true goal all along.
No comments:
Post a Comment