The Week India - July 29, 2018

THE WEEK · JULY 29, 2018 37

HEALTH

Light, in the tunnel

A new immunology treatment

that wiped out cancer from a

lymphoma patient

BY REEMA ABRAHAM

B

ret C., 52, of Appleton, Wisconsin,

was diagnosed with mantle cell lym-

phoma, a cancer of the immune sys-

tem, in 2011. In spite of chemother-

apy, stem cell transplants and medications, his

stubborn cancer would not budge. So when

Bret came to know about a clinical trial option

for a new treatment in 2017, he thought it was

the best bet to extend his life. It was in late Oc-

tober 2017 that he became the fi rst human to

receive a new double-targeted chimeric antigen

receptor (CAR) T-cell treatment at the Medi-

cal College of Wisconsin. Four weeks later, his

cancer was no longer detectable.

The therapy works like this: imagine a dart

board (cancer) with a number of coloured

balloons (cancer proteins), and some nice

darts (T-cells). Of all the differently coloured

balloons, if the darts can hit a specifi cally co-

loured balloon (say, yellow) not just the yel-

low balloons but the dart board as such will

collapse. Now if the darts have a sticky tape

that attaches to just yellow balloons, that will

be best method to bust the whole structure

(cancer).

The fi rst CAR-T therapy with just a single

target was developed by a University of

Pennsylvania team led by Carl June in 2012.

The treatment involved tweaking a person's

T cells (darts) to target a cancer protein called

CD19, or the yellow balloons. However,

some patients with lymphoma and leukemia

do not have CD19 on their cells, while some

lose them halfway through the treatment. It

is as if there were just a few or no yellow bal-

loons. Without the yellow balloons, the darts

had nothing to aim at and the CAR-T thera-

py met with a roadblock.

So now the scientists had to think of tar-

geting more balloons than just the yellow

ones. They now had to target the green bal-

loons too, in addition to the yellow. The darts

would have to be tweaked in such a way that

it can attach itself to both the yellow and the

green balloons, to increase the chances of col-

lapsing the board. In cellular terms, the dual

targets would be two proteins, the CD 19

plus another one.

The team of physicians and researchers of

the Medical College of Wisconsin, Froedtert

Hospital, Children's Hospital of Wisconsin,

and BloodCenter of Wisconsin including

Zhu F., Shah N., Xu H., Schneider D., Oren-

tas R., Dropulic B., Hari P., and Keever-Tay-

lor made this a reality.

They developed a new therapy targeting

two proteins CD19 and CD20. And, Bret

was the fi rst patient to participate in the fi rst

clinical trial for a novel dual-targeted CAR-T

therapy. The cancer had to bow out.

FIRST SURVIVOR: Bret C., who won the battle against lym-

phoma with Dr N. Shah, assistant professor of

medicine in the division of hematology and oncology

at the Froedtert & MCW Clinical Cancer Center, Wisconsin