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  • So this is the first time I've told this story in public,

  • the personal aspects of it.

  • Yogi Berra was a world-famous baseball player who said,

  • "If you come to a fork in the road, take it."

  • Researchers had been, for more than a century,

  • studying the immune system as a way to fight cancer,

  • and cancer vaccines have, unfortunately, been disappointing.

  • They've only worked in cancers caused by viruses,

  • like cervical cancer or liver cancer.

  • So cancer researchers basically gave up on the idea

  • of using the immune system to fight cancer.

  • And the immune system, in any case, did not evolve to fight cancer;

  • it evolved to fight pathogens invading from the outside.

  • So its job is to kill bacteria and viruses.

  • And the reason the immune system has trouble with most cancers

  • is that it doesn't invade from the outside;

  • it evolves from its own cells.

  • And so either the immune system does not recognize the cancer as a problem,

  • or it attacks a cancer and also our normal cells,

  • leading to autoimmune diseases like colitis or multiple sclerosis.

  • So how do you get around that?

  • Our answer turned out to be synthetic immune systems

  • that are designed to recognize and kill cancer cells.

  • That's right -- I said a synthetic immune system.

  • You do that with genetic engineering and synthetic biology.

  • We did it with the naturally occurring parts of the immune system,

  • called B cells and T cells.

  • These were our building blocks.

  • T cells have evolved to kill cells infected with viruses,

  • and B cells are the cells that make antibodies that are secreted

  • and then bind to kill bacteria.

  • Well, what if you combined these two functions

  • in a way that was designed to repurpose them to fight cancer?

  • We realized it would be possible to insert the genes for antibodies

  • from B cells into T cells.

  • So how do you do that?

  • Well, we used an HIV virus as a Trojan horse

  • to get past the T cells' immune system.

  • The result is a chimera,

  • a fantastic fire-breathing creature from Greek mythology,

  • with a lion's head, a goat's body and a serpent's tail.

  • So we decided that the paradoxical thing that we had created

  • with our B-cell antibodies, our T cells carrier

  • and the HIV Trojan horse

  • should be called "Chimeric Antigen Receptor T cells," or CAR T cells.

  • The virus also inserts genetic information

  • to activate the T cells and program them into their killing mode.

  • So when CAR T cells are injected into somebody with cancer,

  • what happens when those CAR T cells see and bind to their tumor target?

  • They act like supercharged killer T cells on steroids.

  • They start this crash-defense buildup system in the body

  • and literally divide and multiply by the millions,

  • where they then attack and kill the tumor.

  • All of this means that CAR T cells are the first living drug in medicine.

  • CAR T cells break the mold.

  • Unlike normal drugs that you take --

  • they do their job and get metabolized, and then you have to take them again --

  • CAR T cells stay alive and on the job for years.

  • We have had CAR T cells stay in the bodies of our cancer patients

  • now for more than eight years.

  • And these designer cancer T cells, CAR T cells,

  • have a calculated half-life of more than 17 years.

  • So one infusion can do the job;

  • they stay on patrol for the rest of your life.

  • This is the beginning of a new paradigm in medicine.

  • Now, there was one major challenge to these T-cell infusions.

  • The only source of T cells that will work in a patient

  • are your own T cells,

  • unless you happen to have an identical twin.

  • So for most of us, we're out of luck.

  • So what we did was to make CAR T cells.

  • We had to learn to grow the patient's own T cells.

  • And we developed a robust platform for this in the 1990s.

  • Then in 1997, we first tested CAR T cells in patients

  • with advanced HIV-AIDS.

  • And we found that those CAR T cells survived in the patients

  • for more than a decade.

  • And it improved their immune system and decreased their viruses,

  • but it didn't cure them.

  • So we went back to the laboratory, and over the next decade

  • made improvements to the CAR T cell design.

  • And by 2010, we began treating leukemia patients.

  • And our team treated three patients

  • with advanced chronic lymphocytic leukemia in 2012.

  • It's a form of incurable leukemia

  • that afflicts approximately 20,000 adults every year in the United States.

  • The first patient that we treated was a retired Marine sergeant

  • and a prison corrections officer.

  • He had only weeks to live

  • and had, in fact, already paid for his funeral.

  • The cells were infused, and within days, he had high fevers.

  • He developed multiple organ failures,

  • was transferred to the ICU and was comatose.

  • We thought he would die,

  • and, in fact, he was given last rites.

  • But then, another fork in the road happened.

  • So, around 28 days after the CAR T cell infusion,

  • he woke up,

  • and the physicians finally examined him,

  • and the cancer was gone.

  • The big masses that had been there had melted.

  • Bone marrow biopsies found no evidence of leukemia,

  • and that year, in our first three patients we treated,

  • two of three have had durable remissions now for eight years,

  • and one had a partial remission.

  • The CAR T cells had attacked the leukemia in these patients

  • and had dissolved between 2.9 and 7.7 pounds of tumor in each patient.

  • Their bodies had become veritable bioreactors for these CAR T cells,

  • producing millions and millions of CAR T cells

  • in the bone marrow, blood and tumor masses.

  • And we discovered that these CAR T cells can punch far above their weight class,

  • to use a boxing analogy.

  • Just one CAR T cell can kill 1,000 tumor cells.

  • That's right -- it's a ratio of one to a thousand.

  • The CAR T cell and its daughter progeny cells

  • can divide and divide and divide in the body

  • until the last tumor cell is gone.

  • There's no precedent for this in cancer medicine.

  • The first two patients who had full remission

  • remain today leukemia-free,

  • and we think they are cured.

  • These are people who had run out of options,

  • and by all traditional methods they had,

  • they were like modern-day Lazarus cases.

  • All I can say is: thank goodness for those forks in the road.

  • Our next step was to get permission to treat children with acute leukemia,

  • the most common form of cancer in kids.

  • The first patient we enrolled on the trial was Emily Whitehead,

  • and at that time, she was six years old.

  • She had gone through a series of chemotherapy

  • and radiation treatments over several years,

  • and her leukemia had always come back.

  • In fact, it had come back three times.

  • When we first saw her, Emily was very ill.

  • Her official diagnosis was advanced, incurable leukemia.

  • Cancer had invaded her bone marrow, her liver, her spleen.

  • And when we infused her with the CAR T cells

  • in the spring of April 2012,

  • over the next few days, she did not get better.

  • She got worse, and in fact, much worse.

  • As our prison corrections officer had in 2010,

  • she, in 2012, was admitted to the ICU,

  • and this was the scariest fork in the whole road of this story.

  • By day three, she was comatose and on life support

  • for kidney failure, lung failure and coma.

  • Her fever was as high as 106 degrees Fahrenheit for three days.

  • And we didn't know what was causing those fevers.

  • We did all the standard blood tests for infections,

  • and we could not find an infectious cause for her fever.

  • But we did find something very unusual in her blood

  • that had never been seen before in medicine.

  • She had elevated levels of a protein called interleukin-6, or IL-6,

  • in her blood.

  • It was, in fact, more than a thousandfold above the normal levels.

  • And here's where yet another fork in the road came in.

  • By sheer coincidence,

  • one of my daughters has a form of pediatric arthritis.

  • And as a result, I had been following as a cancer doc,

  • experimental therapies for arthritis for my daughter,

  • in case she would need them.

  • And it so happened that just months before Emily was admitted to the hospital,

  • a new therapy had been approved by the FDA

  • to treat elevated levels of interleukin-6.

  • And it was approved for the arthritis that my daughter had.

  • It's called tocilizumab.

  • And, in fact, it had just been added to the pharmacy at Emily's hospital,

  • for arthritis.

  • So when we found Emily had these very high levels of IL-6,

  • I called her doctors in the ICU and said,

  • "Why don't you treat her with this arthritis drug?"

  • They said I was a cowboy for suggesting that.

  • And since her fever and low blood pressure

  • had not responded to any other therapy,

  • her doctor quickly asked permission to the institutional review board,

  • her parents,

  • and everybody, of course, said yes.

  • And they tried it,

  • and the results were nothing short of striking.

  • Within hours after treatment with tocilizumab,

  • Emily began to improve very rapidly.

  • Twenty-three days after her treatment,

  • she was declared cancer-free.

  • And today, she's 12 years old and still in remission.

  • (Applause)

  • So we now call this violent reaction of the high fevers and coma,

  • following CAR T cells,

  • cytokine release syndrome, or CRS.

  • We've found that it occurs in nearly all patients who respond to the therapy.

  • But it does not happen in those patients who fail to respond.

  • So paradoxically,

  • our patients now hope for these high fevers after therapy,

  • which feels like "the worst flu in their life,"

  • when they get CAR T-cell therapies.

  • They hope for this reaction

  • because they know it's part of the twisting and turning path

  • back to health.

  • Unfortunately, not every patient recovers.

  • Patients who do not get CRS are often those who are not cured.

  • So there's a strong link now between CRS

  • and the ability of the immune system to eradicate leukemia.

  • That's why last summer,

  • when the FDA approved CAR T cells for leukemia,

  • they also co-approved the use of tocilizumab to block the IL-6 effects

  • and the accompanying CRS in these patients.

  • That was a very unusual event in medical history.

  • Emily's doctors have now completed further trials

  • and reported that 27 out of 30 patients, the first 30 we treated,

  • or 90 percent,

  • had a complete remission

  • after CAR T cells, within a month.

  • A 90 percent complete remission rate in patients with advanced cancer

  • is unheard of

  • in more than 50 years of cancer research.

  • In fact, companies often declare success in a cancer trial

  • if 15 percent of the patients had a complete response rate.

  • A remarkable study appeared in the "New England Journal of Medicine" in 2013.

  • An international study has since confirmed those results.

  • And that led to the approval by the FDA

  • for pediatric and young adult leukemia in August of 2017.

  • So as a first-ever approval of a cell and gene therapy,

  • CAR T-cell therapy has also been tested now

  • in adults with refractory lymphoma.

  • This disease afflicts about 20,000 a year in the United States.

  • The results were equally impressive and have been durable to date.

  • And six months ago, the FDA approved the therapy of this advanced lymphoma

  • with CAR T cells.

  • So now there are many labs and physicians and scientists around the world

  • who have tested CAR T cells

  • across many different diseases,

  • and understandably, we're all thrilled with the rapid pace of advancement.

  • We're so grateful to see patients who were formerly terminal

  • return to healthy lives, as Emily has.

  • We're thrilled to see long remissions that may, in fact, be a cure.

  • At the same time, we're also concerned about the financial cost.

  • It can cost up to 150,000 dollars to make the CAR T cells for each patient.

  • And when you add in the cost of treating CRS and other complications,

  • the cost can reach one million dollars per patient.

  • We must remember that the cost of failure, though, is even worse.

  • The current noncurative therapies for cancer are also expensive

  • and, in addition, the patient dies.

  • So, of course, we'd like to see research done now

  • to make this more efficient

  • and increase affordability to all patients.

  • Fortunately, this is a new and evolving field,

  • and as with many other new therapies and services,

  • prices will come down as industry learns to do things more efficiently.

  • When I think about all the forks in the road

  • that have led to CAR T-cell therapy,

  • there is one thing that strikes me as very important.

  • We're reminded that discoveries of this magnitude don't happen overnight.

  • CAR T-cell therapies came to us after a 30-year journey,

  • along a road full of setbacks and surprises.

  • In all this world of instant gratification

  • and 24/7, on-demand results,

  • scientists require persistence, vision and patience

  • to rise above all that.

  • They can see that the fork in the road is not always a dilemma or a detour;

  • sometimes, even though we may not know it at the time,

  • the fork is the way home.

  • Thank you very much.

  • (Applause)

So this is the first time I've told this story in public,

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TED】カール・ジューン。がんの治療法を変える「生きた薬」 (がんの治療法を変える「生きた薬」|カール・ジューン) (【TED】Carl June: A "living drug" that could change the way we treat cancer (A "living drug" that could change the way we treat cancer | Carl June))

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    林宜悉 に公開 2021 年 01 月 14 日
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