FDA ad­vis­ers back gene ther­apy to treat one form of blind­ness

Santa Fe New Mexican - - NATION & WORLD - By Matthew Per­rone

SIL­VER SPRING, Md. — A po­ten­tially ground­break­ing treat­ment for a rare form of blind­ness moved one step closer to U.S. ap­proval Thurs­day, as fed­eral health ad­vis­ers en­dorsed the ex­per­i­men­tal gene ther­apy for pa­tients with an in­her­ited con­di­tion that grad­u­ally de­stroys eye­sight.

The panel ex­perts to the Food and Drug Ad­min­is­tra­tion voted unan­i­mously in fa­vor of Spark Ther­a­peu­tics’ in­jectable ther­apy, which aims to im­prove vi­sion by re­plac­ing a de­fec­tive gene needed to process light.

The vote amounts to a rec­om­men­da­tion to ap­prove the ther­apy. The FDA has un­til mid-Jan­uary to make its de­ci­sion and does not have to fol­low the panel’s rec­om­men­da­tion, though it often does.

If ap­proved, Lux­turna would be the first gene ther­apy in the U.S. for an in­her­ited dis­ease and the first in which a cor­rec­tive gene is given di­rectly to pa­tients. While the ther­apy from Spark Ther­a­peu­tics tar­gets a small group of pa­tients — about 2,000 in the U.S. — ex­perts say it could pave the way for other ge­netic treat­ments for a va­ri­ety of in­her­ited con­di­tions.

Panelists con­cluded that the science be­hind the drug — based on re­search from the Chil­dren’s Hospi­tal of Philadel­phia — was re­mark­ably strong with few se­ri­ous side ef­fects.

Sev­eral pa­tients at­tended the meet­ing to urge panelists to sup­port the drug, re­lat­ing ex­pe­ri­ences of see­ing snow, stars and the moon for the first time. In most cases, the pa­tients’ travel ex­penses were paid for by the drug’s de­vel­oper.

Ash­ley Carper, a mother of two chil­dren with the dis­or­der, said treat­ment has al­lowed her 11-year-old son Cole to read large-print books and write his own home­work. Pre­vi­ously he could only read with Braille. Cole said the im­prove­ments ex­tend be­yond school­work.

“I can stay out later when my friends are out­side play­ing and now I feel like part of the group,” he said. “My vi­sion is not per­fect, but what I do have is still re­ally im­por­tant to me.”

Re­searchers tested the treat­ment by record­ing pa­tients’ abil­ity to com­plete an ob­sta­cle course at vary­ing lev­els of light, like nav­i­gat­ing a dark stair­well. A hall­mark of the in­her­ited dis­or­der is dif­fi­culty see­ing a night. Pa­tients with the mu­ta­tion gen­er­ally start los­ing their sight be­fore age 18, al­most al­ways pro­gress­ing to to­tal blind­ness.

One year af­ter treat­ment, 18 out of 20 pa­tients who re­ceived the in­jec­tion showed the max­i­mum im­prove­ment in com­plet­ing the ob­sta­cle course, and 13 com­pleted the task at the low­est level of light.

Doc­tors de­liver the ther­apy with an in­jec­tion in each eye that in­serts a re­place­ment gene into the retina via a mod­i­fied virus.

Philadel­phia-based Spark Ther­a­peu­tics hopes to use its tech­nol­ogy to treat other reti­nal dis­or­ders, in­clud­ing one called choroi­deremia, which af­fects about three times as many peo­ple as the con­di­tion un­der FDA re­view. The com­pany is also in­ves­ti­gat­ing ther­a­pies to treat the blood dis­or­der he­mo­philia and dis­eases of the ner­vous sys­tem.

As a po­ten­tial break­through ther­apy for a rare dis­ease, much of the dis­cus­sion around Lux­turna has fo­cused on its cost. Drug­mak­ers often price sim­i­lar drugs at $250,000 or more. Spark has not given an es­ti­mated cost, which com­pa­nies usu­ally an­nounce only af­ter ap­proval. But the com­pany’s stock ticker sym­bol “ONCE” re­in­forces the com­pany’s hope that this will be a one-time treat­ment — and ex­pense. “It is the as­pi­ra­tion,” Spark Ther­a­peu­tics CEO Jeff Mar­razzo told The As­so­ci­ated Press prior to the meet­ing.

Phar­ma­ceu­ti­cal an­a­lyst Michael Yee es­ti­mates the drug will be priced be­tween $350,000 and $450,000 per in­jec­tion. He ex­pects sales of $40 mil­lion to $50 mil­lion in 2018, grow­ing to as much as $100 mil­lion in 2019.

Newspapers in English

Newspapers from USA

© PressReader. All rights reserved.