A "living drug" that could change the way we treat cancer | Carl June

121,252 views ・ 2019-10-02

TED


Please double-click on the English subtitles below to play the video.

00:12
So this is the first time I've told this story in public,
0
12952
2906
00:15
the personal aspects of it.
1
15882
1911
00:19
Yogi Berra was a world-famous baseball player who said,
2
19056
5077
00:24
"If you come to a fork in the road, take it."
3
24157
2322
00:27
Researchers had been, for more than a century,
4
27069
3499
00:30
studying the immune system as a way to fight cancer,
5
30592
2742
00:34
and cancer vaccines have, unfortunately, been disappointing.
6
34482
3460
00:37
They've only worked in cancers caused by viruses,
7
37966
2810
00:40
like cervical cancer or liver cancer.
8
40800
3217
00:45
So cancer researchers basically gave up on the idea
9
45129
2810
00:47
of using the immune system to fight cancer.
10
47963
2856
00:52
And the immune system, in any case, did not evolve to fight cancer;
11
52127
3996
00:56
it evolved to fight pathogens invading from the outside.
12
56147
3382
00:59
So its job is to kill bacteria and viruses.
13
59962
2919
01:03
And the reason the immune system has trouble with most cancers
14
63479
3344
01:06
is that it doesn't invade from the outside;
15
66847
3444
01:10
it evolves from its own cells.
16
70315
3004
01:14
And so either the immune system does not recognize the cancer as a problem,
17
74337
4207
01:18
or it attacks a cancer and also our normal cells,
18
78568
3285
01:21
leading to autoimmune diseases like colitis or multiple sclerosis.
19
81877
4560
01:26
So how do you get around that?
20
86991
1799
01:28
Our answer turned out to be synthetic immune systems
21
88814
4834
01:33
that are designed to recognize and kill cancer cells.
22
93672
3175
01:37
That's right -- I said a synthetic immune system.
23
97609
3400
01:42
You do that with genetic engineering and synthetic biology.
24
102978
4190
01:47
We did it with the naturally occurring parts of the immune system,
25
107780
3152
01:50
called B cells and T cells.
26
110956
1930
01:52
These were our building blocks.
27
112910
2267
01:55
T cells have evolved to kill cells infected with viruses,
28
115522
3674
01:59
and B cells are the cells that make antibodies that are secreted
29
119220
4139
02:03
and then bind to kill bacteria.
30
123383
2595
02:07
Well, what if you combined these two functions
31
127012
4343
02:11
in a way that was designed to repurpose them to fight cancer?
32
131379
4071
02:15
We realized it would be possible to insert the genes for antibodies
33
135474
3627
02:19
from B cells into T cells.
34
139125
2181
02:21
So how do you do that?
35
141854
1468
02:24
Well, we used an HIV virus as a Trojan horse
36
144109
4046
02:28
to get past the T cells' immune system.
37
148179
2820
02:32
The result is a chimera,
38
152464
1587
02:34
a fantastic fire-breathing creature from Greek mythology,
39
154075
4113
02:38
with a lion's head, a goat's body and a serpent's tail.
40
158212
3690
02:42
So we decided that the paradoxical thing that we had created
41
162720
3659
02:46
with our B-cell antibodies, our T cells carrier
42
166403
4193
02:50
and the HIV Trojan horse
43
170620
2068
02:52
should be called "Chimeric Antigen Receptor T cells," or CAR T cells.
44
172712
4865
02:58
The virus also inserts genetic information
45
178538
2983
03:01
to activate the T cells and program them into their killing mode.
46
181545
3732
03:05
So when CAR T cells are injected into somebody with cancer,
47
185915
4079
03:10
what happens when those CAR T cells see and bind to their tumor target?
48
190018
4338
03:14
They act like supercharged killer T cells on steroids.
49
194688
3706
03:19
They start this crash-defense buildup system in the body
50
199197
3396
03:22
and literally divide and multiply by the millions,
51
202617
3060
03:25
where they then attack and kill the tumor.
52
205701
2295
03:28
All of this means that CAR T cells are the first living drug in medicine.
53
208550
5055
03:34
CAR T cells break the mold.
54
214375
1464
03:35
Unlike normal drugs that you take --
55
215863
2254
03:38
they do their job and get metabolized, and then you have to take them again --
56
218141
4174
03:42
CAR T cells stay alive and on the job for years.
57
222339
3704
03:46
We have had CAR T cells stay in the bodies of our cancer patients
58
226530
4559
03:51
now for more than eight years.
59
231113
1877
03:54
And these designer cancer T cells, CAR T cells,
60
234196
3238
03:57
have a calculated half-life of more than 17 years.
61
237458
3968
04:01
So one infusion can do the job;
62
241450
1948
04:03
they stay on patrol for the rest of your life.
63
243422
2503
04:06
This is the beginning of a new paradigm in medicine.
64
246403
2744
04:10
Now, there was one major challenge to these T-cell infusions.
65
250173
4644
04:15
The only source of T cells that will work in a patient
66
255903
4267
04:20
are your own T cells,
67
260194
1167
04:21
unless you happen to have an identical twin.
68
261385
2288
04:24
So for most of us, we're out of luck.
69
264234
2163
04:28
So what we did was to make CAR T cells.
70
268440
3845
04:32
We had to learn to grow the patient's own T cells.
71
272309
3048
04:35
And we developed a robust platform for this in the 1990s.
72
275381
3983
04:39
Then in 1997, we first tested CAR T cells in patients
73
279831
4032
04:43
with advanced HIV-AIDS.
74
283887
1849
04:46
And we found that those CAR T cells survived in the patients
75
286268
3098
04:49
for more than a decade.
76
289390
1584
04:50
And it improved their immune system and decreased their viruses,
77
290998
3015
04:54
but it didn't cure them.
78
294037
1366
04:55
So we went back to the laboratory, and over the next decade
79
295427
2841
04:58
made improvements to the CAR T cell design.
80
298292
2857
05:01
And by 2010, we began treating leukemia patients.
81
301173
3847
05:05
And our team treated three patients
82
305663
2357
05:08
with advanced chronic lymphocytic leukemia in 2012.
83
308044
3738
05:11
It's a form of incurable leukemia
84
311806
2668
05:14
that afflicts approximately 20,000 adults every year in the United States.
85
314498
4285
05:19
The first patient that we treated was a retired Marine sergeant
86
319887
5034
05:24
and a prison corrections officer.
87
324945
1926
05:26
He had only weeks to live
88
326895
1309
05:28
and had, in fact, already paid for his funeral.
89
328228
4199
05:33
The cells were infused, and within days, he had high fevers.
90
333450
4147
05:37
He developed multiple organ failures,
91
337621
1777
05:39
was transferred to the ICU and was comatose.
92
339422
2349
05:41
We thought he would die,
93
341795
1564
05:43
and, in fact, he was given last rites.
94
343383
2452
05:45
But then, another fork in the road happened.
95
345859
4839
05:50
So, around 28 days after the CAR T cell infusion,
96
350722
2984
05:53
he woke up,
97
353730
1157
05:54
and the physicians finally examined him,
98
354911
2254
05:57
and the cancer was gone.
99
357189
1268
05:58
The big masses that had been there had melted.
100
358481
2300
06:01
Bone marrow biopsies found no evidence of leukemia,
101
361823
2397
06:04
and that year, in our first three patients we treated,
102
364244
3000
06:07
two of three have had durable remissions now for eight years,
103
367268
3256
06:10
and one had a partial remission.
104
370548
2266
06:13
The CAR T cells had attacked the leukemia in these patients
105
373230
3300
06:16
and had dissolved between 2.9 and 7.7 pounds of tumor in each patient.
106
376554
6780
06:24
Their bodies had become veritable bioreactors for these CAR T cells,
107
384649
4833
06:29
producing millions and millions of CAR T cells
108
389506
2857
06:32
in the bone marrow, blood and tumor masses.
109
392387
3787
06:36
And we discovered that these CAR T cells can punch far above their weight class,
110
396511
4285
06:40
to use a boxing analogy.
111
400820
1556
06:42
Just one CAR T cell can kill 1,000 tumor cells.
112
402718
4159
06:47
That's right -- it's a ratio of one to a thousand.
113
407697
2902
06:50
The CAR T cell and its daughter progeny cells
114
410623
3018
06:53
can divide and divide and divide in the body
115
413665
2436
06:56
until the last tumor cell is gone.
116
416125
2135
06:58
There's no precedent for this in cancer medicine.
117
418284
2549
07:01
The first two patients who had full remission
118
421379
3180
07:04
remain today leukemia-free,
119
424583
3076
07:07
and we think they are cured.
120
427683
1590
07:09
These are people who had run out of options,
121
429297
2475
07:13
and by all traditional methods they had,
122
433106
2677
07:15
they were like modern-day Lazarus cases.
123
435807
2667
07:18
All I can say is: thank goodness for those forks in the road.
124
438870
3694
07:23
Our next step was to get permission to treat children with acute leukemia,
125
443196
4510
07:27
the most common form of cancer in kids.
126
447730
2665
07:30
The first patient we enrolled on the trial was Emily Whitehead,
127
450419
3023
07:33
and at that time, she was six years old.
128
453466
2048
07:35
She had gone through a series of chemotherapy
129
455538
2626
07:38
and radiation treatments over several years,
130
458188
2540
07:40
and her leukemia had always come back.
131
460752
1850
07:42
In fact, it had come back three times.
132
462626
2271
07:45
When we first saw her, Emily was very ill.
133
465276
2800
07:51
Her official diagnosis was advanced, incurable leukemia.
134
471244
3895
07:55
Cancer had invaded her bone marrow, her liver, her spleen.
135
475822
3223
08:00
And when we infused her with the CAR T cells
136
480179
2824
08:03
in the spring of April 2012,
137
483027
2642
08:05
over the next few days, she did not get better.
138
485693
2549
08:08
She got worse, and in fact, much worse.
139
488550
2793
08:11
As our prison corrections officer had in 2010,
140
491367
3222
08:14
she, in 2012, was admitted to the ICU,
141
494613
2986
08:17
and this was the scariest fork in the whole road of this story.
142
497623
3341
08:21
By day three, she was comatose and on life support
143
501559
3605
08:26
for kidney failure, lung failure and coma.
144
506522
3195
08:30
Her fever was as high as 106 degrees Fahrenheit for three days.
145
510263
4377
08:35
And we didn't know what was causing those fevers.
146
515239
2743
08:38
We did all the standard blood tests for infections,
147
518730
2395
08:41
and we could not find an infectious cause for her fever.
148
521149
3530
08:44
But we did find something very unusual in her blood
149
524703
3937
08:48
that had never been seen before in medicine.
150
528664
2328
08:51
She had elevated levels of a protein called interleukin-6, or IL-6,
151
531374
5344
08:56
in her blood.
152
536742
1168
08:57
It was, in fact, more than a thousandfold above the normal levels.
153
537934
5028
09:03
And here's where yet another fork in the road came in.
154
543450
3222
09:08
By sheer coincidence,
155
548548
1627
09:10
one of my daughters has a form of pediatric arthritis.
156
550199
4690
09:16
And as a result, I had been following as a cancer doc,
157
556505
3199
09:19
experimental therapies for arthritis for my daughter,
158
559728
3801
09:23
in case she would need them.
159
563553
1373
09:24
And it so happened that just months before Emily was admitted to the hospital,
160
564950
4223
09:29
a new therapy had been approved by the FDA
161
569197
2916
09:32
to treat elevated levels of interleukin-6.
162
572137
2710
09:34
And it was approved for the arthritis that my daughter had.
163
574871
2770
09:37
It's called tocilizumab.
164
577665
1600
09:40
And, in fact, it had just been added to the pharmacy at Emily's hospital,
165
580584
5134
09:45
for arthritis.
166
585742
1653
09:47
So when we found Emily had these very high levels of IL-6,
167
587419
3079
09:50
I called her doctors in the ICU and said,
168
590522
2738
09:53
"Why don't you treat her with this arthritis drug?"
169
593284
2982
09:56
They said I was a cowboy for suggesting that.
170
596700
2793
09:59
And since her fever and low blood pressure
171
599517
2437
10:01
had not responded to any other therapy,
172
601978
3290
10:05
her doctor quickly asked permission to the institutional review board,
173
605292
3310
10:08
her parents,
174
608626
1157
10:09
and everybody, of course, said yes.
175
609807
1810
10:11
And they tried it,
176
611641
1201
10:12
and the results were nothing short of striking.
177
612866
3152
10:16
Within hours after treatment with tocilizumab,
178
616701
2658
10:19
Emily began to improve very rapidly.
179
619383
2897
10:22
Twenty-three days after her treatment,
180
622764
3334
10:26
she was declared cancer-free.
181
626122
2074
10:28
And today, she's 12 years old and still in remission.
182
628220
4858
10:34
(Applause)
183
634840
6976
10:44
So we now call this violent reaction of the high fevers and coma,
184
644707
5826
10:50
following CAR T cells,
185
650557
1158
10:51
cytokine release syndrome, or CRS.
186
651739
2624
10:54
We've found that it occurs in nearly all patients who respond to the therapy.
187
654387
3865
10:58
But it does not happen in those patients who fail to respond.
188
658276
3373
11:01
So paradoxically,
189
661673
1658
11:04
our patients now hope for these high fevers after therapy,
190
664466
4460
11:08
which feels like "the worst flu in their life,"
191
668950
2802
11:11
when they get CAR T-cell therapies.
192
671776
1770
11:13
They hope for this reaction
193
673570
1305
11:14
because they know it's part of the twisting and turning path
194
674899
3130
11:18
back to health.
195
678053
1326
11:19
Unfortunately, not every patient recovers.
196
679403
2350
11:22
Patients who do not get CRS are often those who are not cured.
197
682458
3946
11:27
So there's a strong link now between CRS
198
687258
3175
11:30
and the ability of the immune system to eradicate leukemia.
199
690457
3041
11:33
That's why last summer,
200
693973
1159
11:35
when the FDA approved CAR T cells for leukemia,
201
695156
5190
11:41
they also co-approved the use of tocilizumab to block the IL-6 effects
202
701252
6118
11:47
and the accompanying CRS in these patients.
203
707394
3011
11:50
That was a very unusual event in medical history.
204
710711
3025
11:54
Emily's doctors have now completed further trials
205
714784
4691
11:59
and reported that 27 out of 30 patients, the first 30 we treated,
206
719499
4608
12:04
or 90 percent,
207
724131
1156
12:05
had a complete remission
208
725311
1383
12:08
after CAR T cells, within a month.
209
728175
2203
12:10
A 90 percent complete remission rate in patients with advanced cancer
210
730830
4500
12:15
is unheard of
211
735354
1156
12:16
in more than 50 years of cancer research.
212
736534
2873
12:19
In fact, companies often declare success in a cancer trial
213
739431
4765
12:24
if 15 percent of the patients had a complete response rate.
214
744220
3548
12:28
A remarkable study appeared in the "New England Journal of Medicine" in 2013.
215
748180
4469
12:32
An international study has since confirmed those results.
216
752673
3316
12:36
And that led to the approval by the FDA
217
756442
3572
12:40
for pediatric and young adult leukemia in August of 2017.
218
760038
4356
12:45
So as a first-ever approval of a cell and gene therapy,
219
765275
3427
12:48
CAR T-cell therapy has also been tested now
220
768726
2216
12:50
in adults with refractory lymphoma.
221
770966
2572
12:53
This disease afflicts about 20,000 a year in the United States.
222
773885
3705
12:58
The results were equally impressive and have been durable to date.
223
778004
3795
13:02
And six months ago, the FDA approved the therapy of this advanced lymphoma
224
782172
4877
13:07
with CAR T cells.
225
787073
1432
13:08
So now there are many labs and physicians and scientists around the world
226
788974
5017
13:14
who have tested CAR T cells
227
794015
2097
13:16
across many different diseases,
228
796136
2810
13:18
and understandably, we're all thrilled with the rapid pace of advancement.
229
798970
4437
13:23
We're so grateful to see patients who were formerly terminal
230
803431
3603
13:27
return to healthy lives, as Emily has.
231
807058
3143
13:30
We're thrilled to see long remissions that may, in fact, be a cure.
232
810892
3166
13:34
At the same time, we're also concerned about the financial cost.
233
814363
3809
13:38
It can cost up to 150,000 dollars to make the CAR T cells for each patient.
234
818196
4825
13:43
And when you add in the cost of treating CRS and other complications,
235
823696
3655
13:47
the cost can reach one million dollars per patient.
236
827375
3324
13:51
We must remember that the cost of failure, though, is even worse.
237
831343
3453
13:55
The current noncurative therapies for cancer are also expensive
238
835271
3315
13:58
and, in addition, the patient dies.
239
838610
2493
14:01
So, of course, we'd like to see research done now
240
841744
2776
14:04
to make this more efficient
241
844544
2820
14:08
and increase affordability to all patients.
242
848367
2419
14:11
Fortunately, this is a new and evolving field,
243
851176
2231
14:13
and as with many other new therapies and services,
244
853431
3544
14:16
prices will come down as industry learns to do things more efficiently.
245
856999
4253
14:21
When I think about all the forks in the road
246
861737
2079
14:23
that have led to CAR T-cell therapy,
247
863840
2110
14:25
there is one thing that strikes me as very important.
248
865974
2720
14:29
We're reminded that discoveries of this magnitude don't happen overnight.
249
869474
3579
14:33
CAR T-cell therapies came to us after a 30-year journey,
250
873426
4326
14:37
along a road full of setbacks and surprises.
251
877776
2960
14:41
In all this world of instant gratification
252
881093
2412
14:43
and 24/7, on-demand results,
253
883529
3048
14:46
scientists require persistence, vision and patience
254
886601
4128
14:50
to rise above all that.
255
890753
1533
14:52
They can see that the fork in the road is not always a dilemma or a detour;
256
892816
4913
14:57
sometimes, even though we may not know it at the time,
257
897753
3310
15:01
the fork is the way home.
258
901087
1667
15:03
Thank you very much.
259
903452
1326
15:04
(Applause)
260
904802
3876
About this website

This site will introduce you to YouTube videos that are useful for learning English. You will see English lessons taught by top-notch teachers from around the world. Double-click on the English subtitles displayed on each video page to play the video from there. The subtitles scroll in sync with the video playback. If you have any comments or requests, please contact us using this contact form.

https://forms.gle/WvT1wiN1qDtmnspy7