Gene therapy has released 10 men from almost all the symptoms of hemophilia for a year so far, in a study that feeds the hope that a treatment at one time can provide long-term help. and maybe even cure the blood disease.
Hemophilia almost always attacks men and is caused by the lack of a gene that produces a protein needed for blood to clot. Small cuts or bruises can be life-threatening, and many people need treatments one or more times a week to prevent serious bleeding.
The therapy supplies the missing gene, using a virus that has been modified so that it does not cause disease, but the ferries the DNA instructions to the cells of the liver, which use them to create the coagulation factor. The treatment is given intravenously.
In a study published Wednesday by the New England Journal of Medicine, the 10 men who received the therapy now have a clotting factor within the normal range. Bleeding episodes were reduced from about one a month before gene therapy to less than one a year. Nine of the 10 no longer need treatments with coagulation factor, and the tenth needs much less. There were no serious side effects.
The follow-up is still short, one year on average. Some cells with the new gene may not be transmitted as they divide, so the benefits may decrease over time, but have lasted eight years in other tests in people and up to 12 years so far in dogs.
"The hope is that this is a one-time treatment" to solve the problem, said study leader, Dr. Lindsey George of the Children's Hospital of Philadelphia.
Spark Therapeutics, the Philadelphia-based treatment company, and Pfizer, which is now working with Spark, paid for the study, and some of the study leaders work for Spark or have shares in Spark.
Dr. Matthew Porteus of Stanford University, who wrote a commentary in the journal, called the results "surprising" and said: "I think we're definitely on the way" to a cure.
It feels like one for Canadians Jay and Bill Konduros, brothers who live an hour's drive from Toronto who were in the studio.
"It's pretty magical," said Jay Konduros, 53, who runs a bakery and was cared for in June 2016.
"Change your life," said Bill Konduros, 58, a machinist March.
Earlier, even small amounts of effort caused small muscle tears and bleeding problems that required treatment of the coagulation factor.
"Even something as innocuous as stretching your head to get something out of a closet, or reaching out to tie a shoe" could cause problems, Bill Konduros said.
Six years ago, he was about to lose a leg after a motorcycle accident opened an artery; He spent almost a month in the hospital. Since gene therapy, none of the siblings have needed treatment with coagulation factor.
The therapy is still experimental and its final cost is unknown, but treatment of the clotting factor costs approximately $ 200,000 per patient per year, said Porteus.
Another gene therapy from BioMarin Pharmaceutical for a different form of hemophilia, also showed promise in a different study. Thirteen patients have been treated and have had a large drop in bleeding episodes and coagulation factor treatments, report the study leaders. The results of a year will be given at a conference of the American Society of Hematology that begins on Saturday.
Other companies are working on treatments for hemophilia; Sangamo Therapeutics is testing traditional gene therapy and gene editing approaches.
This story has been corrected to show that Spark Therapeutics is based in Philadelphia, not Cambridge, Massachusetts.
Marilynn Marchione can be followed on Twitter: @MMarchioneAP
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