Page 12 - HOH UPDATED

A28 SCIENCE
Friday 8 February 2019

Tests suggest scientists achieved 1st ‘in body’ gene editing

Hurler patients, said Dr. Paul
Harmatz of UCSF Benioff
Children’s Hospital Oak-
land, who presented those
results. None of the patients
with either disease showed
a sustained decline in urine
levels of the troubling sugar
compounds, though, and
some other tests also did
not detect intended ef-
fects of the therapy.
The key test will be stop-
ping the patients’ weekly
enzyme treatments to see
if their bodies can now
make enough of it on their
own. Three have gone off
treatments so far and one
was recently advised to
resume them because of
fatigue and rising levels of
the sugar compounds. The
others have not been off
long enough to know how
they will fare. “It looks like
it’s safe ... that’s a very pos-
itive sign,” said one inde-
pendent expert, Dr. Kiran
Musunuru of the University
of Pennsylvania. He called
the early results promising
but said “it’s hard to be sure
it’s doing any good” until
patients are studied longer.
In this Monday, Nov. 13, 2017 file photo, Brian Madeux, starts to receive the first human gene editing therapy for Hunter syndrome, “What they’re trying to do
as his girlfriend, Marcie Humphrey, left, applauds at the UCSF Benioff Children’s Hospital in Oakland, Calif. with gene editing is very
Associated Press challenging,” he said. “It’s
By MARILYNN MARCHIONE “This is a first step,” said Dr. diseases is not controver- — bronchitis, an irregular much harder to make a
AP Chief Medical Writer Joseph Muenzer of the Uni- sial and the DNA changes heartbeat and a hernia correction or insert a gene”
Scientists think they have versity of North Carolina at do not pass to future gen- — were deemed due to than to disable one.
achieved the first gene ed- Chapel Hill, who helped erations, unlike the recent the diseases, not the treat- Dr. Tyler Reimschisel of Van-
iting inside the body, alter- test the treatment. “It’s just case of a Chinese scientist ment. derbilt University agreed.
ing DNA in adults to try to not potent enough.” who claims to have edited Tissue samples showed evi- “It’s not discouraging, it’s
treat a disease, although He gave the results Thurs- twin girls’ genes when they dence of gene editing at just early and on a small
it’s too soon to know if this day at a conference in were embryos. very low levels in two Hunter amount of people,” he
will help. Orlando, Florida, and has Sangamo’s studies involve patients who were given a said. “This is definitely a
Preliminary results suggest consulted for the therapy’s men with Hunter or Hurler middle dose but not in one novel and innovative treat-
that two men with a rare maker, California-based syndrome, diseases caused given a low dose. Tests are ment” but it’s not clear if it’s
disorder now have a cor- Sangamo Therapeutics. by a missing gene that expected later this year on going to help.
rective gene at very low Researchers are working makes an enzyme to break patients who received the Sangamo’s president, Dr.
levels, which may not be on a stronger version of the down certain sugar com- highest dose and on Hurler Sandy Macrae, said a more
enough to make the ther- treatment. pounds. Without it, sugars patients. Blood tests de- potent version is being
apy a success. Gene editing is intended build up and damage or- tected slightly higher levels manufactured. Because
Still, it’s a scientific mile- as a more precise way to gans, often killing people in of the missing enzyme in a the treatment seems safe,
stone toward one day doc- do gene therapy, to dis- their teens. few of the Hunter patients regulators recently agreed
toring DNA to treat many able a bad gene or supply In 2017, Brian Madeux of Ar- but none of them reached to allow teens with Hunter
diseases caused by faulty a good one that’s missing. izona became the first per- normal levels. One patient syndrome to join the study.
genes. Trying it in adults to treat son to try it. Through an IV, had a larger increase but The ultimate goal is to treat
he received many copies also showed signs that his children at a young age,
of a corrective gene and immune system might be before the disease causes
an editing tool called zinc attacking the therapy. He much damage. He said
finger nucleases to insert it was treated for that and the company will wait for
into his DNA. symptoms resolved. more results on current pa-
Results on him and seven More encouraging results tients before deciding how
other Hunter patients, plus were seen in Hurler pa- to proceed.
three with Hurler syndrome, tients — enzyme levels rose “We’ve done something
suggest the treatment is to normal in all three after important” by achiev-
safe, which was the main treatment, tests on certain ing gene editing, he said.
goal of these early ex- blood cells showed. “There is a foundation to
periments. Three problems “This is very promising” for build on.”q