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Παρασκευή 6 Νοεμβρίου 2015

A Novel Cell Therapy Untested in Humans Saves Baby With Cancer


A baby girl who was close to dying from cancer has been rescued by a 
cell therapy envisioned as a “one size fits all” treatment that had never 
been tested in people, doctors reported on Thursday.

The development is significant because it indicates that cell therapies, 
which represent an exciting new front in the battle against cancer
might not have to be customized for each patient, saving time and money.
It also represents one of the first times that a novel “genome editing” 
technique has been used to treat someone. 
The therapy was developed by Cellectis, a French biotechnology company.
But it is hard to say much based on one patient. 
Also, the girl has been in remission for only a few months, too little time 
to say she has been cured, said Waseem Qasim, one of the doctors who 
treated her at the Great Ormond Street Hospital in London.
Still, the girl’s doctors “think it is a remarkable outcome,” because 
she had not been helped by conventional therapies, Dr. Qasim 
said in an interview.
Cancer doctors have been electrified by a new approach that involves 
genetically altering patients’ T cells, the soldiers of the immune system, 
so that they can better attack cancers.
Some patients with certain blood cancers have made remarkable recoveries. 
They include a girl who received a treatment developed at the University 
of Pennsylvania and now licensed to Novartis. 
Other companies pursuing this approach, often called CAR-T, including Juno 
Therapeutics and Kite Pharma, have achieved large stock market valuations.
But the first versions of their experimental therapies require extracting 
the T cells from the patient, shipping them to a manufacturing plant where 
they can be altered, then sending them back and putting them back into 
the patient, something that will be logistically challenging and costly 
for thousands of patients. 
Cellectis’s therapy is meant to work for any patient with a particular 
type of leukemia.
Cellectis’s American depositary receipts soared 18 percent on Thursday,
 while shares of Juno fell 7 percent and those of Kite dipped 2 percent.
Still the personalized treatments could reach the market in the next couple 
of years, long before Cellectis’s treatment, which will not even enter 
early-stage clinical trials until next year.
The case of the girl’s recovery will be presented to doctors next month 
at the annual meeting of the American Society of Hematology in Orlando, Fla. Butabstracts for that conference were made public Thursday, 
and the hospital publicized the case.
The girl, Layla Richards of London, had acute lymphoblastic leukemia. 
Doctors tried the usual chemotherapy, a bone marrow transplant and a new 
type of biotech drug, but nothing worked. Layla did not have enough T cells 
to allow doctors to extract them and make a personalized therapy.
Her parents, Ashleigh Richards and Lisa Foley, were counseled to consider 
palliative care to keep her comfortable until she died, Dr. Qasim said. 
But the parents were not willing to do that.
In what might be a lucky coincidence, the hospital was already manufacturing 
Cellectis’s cells in preparation for clinical trials. 
“We had them in our freezers,” Dr. Qasim said. 
He is also a professor at University College London, which worked with 
Cellectis on the treatment.
So, with permission from her parents and Cellectis, Layla became the first 
person to receive the treatment, on what is sometimes called a 
compassionate use basis.
After getting the cells around the time of her first birthday in June, 
Layla went into remission, with no trace of leukemia found in her blood 
or bone marrow. She later had a second bone marrow transplant to help 
her immune system recover and is now at home.
Cellectis’s therapy uses T cells from a healthy donor that are first modified 
to target leukemia cells in much the same way Novartis and the others 
modify a patient’s own cells.
But to make its treatment “universal,” Cellectis then takes another step 
using another new technology that is generating huge excitement 
— genome editing. This refers to using molecular scissors to make precise 
changes to DNA, just as one might edit a word in a document. 
The genome editing technique that has gotten the most attention is known 
as Crispr-Cas9, though Cellectis used an older approach known as Talens.
A big concern with a nonpersonalized therapy is that the transplanted T cells 
will recognize the patient’s own cells as “foreign” and attack them. 
Cellectis used genome editing to knock out a gene so the transplanted T cells 
could not do that. It also inactivated another gene to help the 
transplanted T cells survive in the patient’s body.
Servier, a French drug company, has an option to acquire the commercial 
rights to this treatment. Cellectis also has a partnership with Pfizer.
In other news related to the hematology conference, shares of Bluebird Bio 
sank 22 percent on Thursday when an abstract suggested that its 
experimental gene therapy for the rare blood disease beta thalassemia
would not work as well in the most severely ill patients as it had 
in less severe cases.

http://www.nytimes.com

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