Doc­tors try 1st CRISPR edit­ing in the body for blind­ness

Times-Herald (Vallejo) - - NEWS - By Marilynn Marchione

Sci­en­tists say they have used the gene edit­ing tool CRISPR in­side some­one’s body for the first time, a new fron­tier for ef­forts to op­er­ate on DNA, the chem­i­cal code of life, to treat dis­eases.

A pa­tient re­cently had it done at the Casey Eye In­sti­tute at Ore­gon Health & Science Univer­sity in Port­land for an in­her­ited form of blind­ness, the com­pa­nies that make the treat­ment an­nounced Wed­nes­day. They would not give de­tails on the pa­tient or when the surgery oc­curred.

It may take up to a month to see if it worked to re­store vi­sion. If the first few at­tempts seem safe, doc­tors plan to test it on 18 chil­dren and adults.

“We lit­er­ally have the po­ten­tial to take peo­ple who are es­sen­tially blind and make them see,” said Charles Al­bright, chief sci­en­tific of­fi­cer at Edi­tas Medicine, the Cam­bridge, Mas­sachusetts-based com­pany de­vel­op­ing the treat­ment with Dublin-based Al­ler­gan. “We think it could open up a whole new set of medicines to go in and change your DNA.”

Dr. Ja­son Co­man­der, an eye sur­geon at Mas­sachusetts Eye and Ear in Bos­ton, an­other hos­pi­tal that plans to en­roll pa­tients in the study, said it marks “a new era in medicine” us­ing a tech­nol­ogy that “makes edit­ing DNA much eas­ier and much more ef­fec­tive.”

Doc­tors first tried in-the­body gene edit­ing in 2017 for a dif­fer­ent in­her­ited dis­ease us­ing a tool called zinc fin­gers. Many sci­en­tists be­lieve CRISPR is a much eas­ier tool for lo­cat­ing and cut­ting DNA at a spe­cific spot, so in­ter­est in the new re­search is very high.

The peo­ple in this study have Le­ber con­gen­i­tal amau­ro­sis, caused by a gene mu­ta­tion that keeps the body from mak­ing a pro­tein needed to con­vert light into sig­nals to the brain, which en­ables sight. They’re of­ten born with lit­tle vi­sion and can lose even that within a few years.

Sci­en­tists can’t treat it with stan­dard gene ther­apy — sup­ply­ing a re­place­ment gene — be­cause the one needed is too big to fit in­side the dis­abled viruses that are used to ferry it into cells.

So they’re aim­ing to edit, or delete the mu­ta­tion by mak­ing two cuts on ei­ther side of it. The hope is that the ends of DNA will re­con­nect and al­low the gene to work as it should.

It’s done in an hour-long surgery un­der gen­eral anes­the­sia. Through a tube the width of a hair, doc­tors drip three drops of fluid con­tain­ing the gene edit­ing ma­chin­ery just be­neath the retina, the lin­ing at the back of the eye that con­tains the light-sens­ing cells.

“Once the cell is edited, it’s per­ma­nent and that cell will per­sist hope­fully for the life of the pa­tient,” be­cause th­ese cells don’t di­vide, said one study leader not in­volved in this first case, Dr. Eric Pierce at Mas­sachusetts Eye and Ear.

Doc­tors think they need to fix one tenth to one third of the cells to re­store vi­sion. In an­i­mal tests, sci­en­tists were able to cor­rect half of the cells with the treat­ment, Al­bright said.

The eye surgery it­self poses lit­tle risk, doc­tors say. In­fec­tions and bleed­ing are rel­a­tively rare com­pli­ca­tions.

One of the big­gest po­ten­tial risks from gene edit­ing is that CRISPR could make un­in­tended changes in other genes, but the com­pa­nies have done a lot to min­i­mize that and to en­sure that the treat­ment cuts only where it’s in­tended to, Pierce said. He has con­sulted for Edi­tas and helped test a gene ther­apy, Lux­turna, that’s sold for a dif­fer­ent type of in­her­ited blind­ness.

Some in­de­pen­dent ex­perts were op­ti­mistic about the new study.

“The gene edit­ing ap­proach is re­ally ex­cit­ing. We need tech­nol­ogy that will be able to deal with prob­lems like th­ese large genes,” said Dr. Jean Ben­nett, a Univer­sity of Penn­syl­va­nia re­searcher who helped test Lux­turna at the Chil­dren’s Hos­pi­tal of Philadel­phia.

In one day, she had three calls from fam­i­lies seek­ing so­lu­tions to in­her­ited blind­ness.

RODRIQUE NGOWI — THE ASSOCIATED PRESS

Dr. Ja­son Co­man­der, in­her­ited reti­nal dis­or­der spe­cial­ist at Mas­sachusetts Eye and Ear In­fir­mary in Bos­ton, points to a model of an eye dur­ing an in­ter­view on Jan. 8. Co­man­der’s hos­pi­tal plans to en­roll pa­tients in a gene-edit­ing treat­ment for a blind­ness study.

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