Scientists are edging closer to defeating a longtime enemy of human health: hemophilia, the lack to make blood clots.
After trying for many years to develop a gene therapy to treat this disease, researchers are beginning to succeed.
In recent experiments, brief intravenous infusions of powerful new treatments have rid patients — for now, a minimum of — of a condition that has shadowed all of them their lives.
There are setbacks — years of failed clinical trials and dashed hopes. Just last week, a biotech company reported that gene therapy mostly stopped working in two of 12 patients in one trial.
But the overall trajectory has been forward, and new treatments are expected by many experts to be approved during a few years.
No one is saying yet that hemophilia is going to be cured.
Currently the gene therapy — which uses an epidemic to deliver a replacement gene to cells — can only be used once. If it stops working, the patients lose their advantages.
For now, “we are anticipating that this is often a once-in-a-lifetime treatment,” said Dr. Steven Pipe, director of the hemophilia and coagulation disorders program at the University of Michigan and a lead investigator of a clinical test conducted by the biotech company BioMarin.
The successful treatments are so recent it's hard to mention how long they're going to last.
except for the few patients who are through the clinical trials successfully, life after treatment is so different that it’s something of a shock.
There are 20,000 hemophilia patients within us who lack one among two proteins needed for blood to clot.
It’s a genetic condition, and therefore the gene for blood coagulation sits on the X chromosome. Virtually all people with hemophilia are men.
Those most severely affected must inject themselves every few days with the missing proteins, coagulation factor VIII, or Christmas factor.
The shots keep hemophiliacs alive, but levels of clotting proteins drop between injections.
Even with regular injections, people with hemophilia risk uncontrolled bleeding into a muscle or joint, or maybe the brain. they need to be extremely careful.
Once bleeding begins, a joint may bulge because the joint space fills with blood. When the bleeding stops, the joint could also be damaged.
Even a routine flight is risky, said Mark Skinner, a 57-year-old attorney in Washington with hemophilia who may be a past president of the planet Federation of Hemophilia.
“Carrying luggage around, you'll twist the incorrect way and immediately trigger a bleed,” he said. “Or you'll get hit with a cart taking place the aisle.”
People with hemophilia often are taught as children to avoid most sports and to seek out professions that will not require much physical activity. Many move to cities to realize easier access to treatment.
They may change jobs to urge insurance needed to hide medical bills for hospitalizations and surgeries which will reach $1 million a year, plus a mean of $250,000 to $300,000 a year for the clotting proteins.
(The shots alone can cost the maximum amount as $1 million per annum.)
Despite their vigilance, most with the severe disease eventually develop permanent joint damage from bleeds, often resulting in surgery for ankle fusion or hip or knee replacements at an early age. Most accept chronic pain from past bleeds.
For older patients, there's a further complication. The clotting proteins utilized in the 1980s were contaminated with H.I.V. and hepatitis C. Nearly everyone with hemophilia got infected.
Now, though, researchers see the beginning of a replacement era.
“It’s a very optimistic time,” said Dr. Lindsey A. George, a hematologist at the Children’s Hospital of Philadelphia and a PI for Spark Therapeutics, one among several companies developing gene therapies for hemophilia.
The goal of gene therapy is to scale back or eliminate patients’ need for injections with coagulation factor and to scale back the amount of bleeds.
The gene to be inserted depends on whether the patient has hemophilia A, caused by a mutation within the gene for antihemophilic factor, or hemophilia B, caused by a mutation within the gene for coagulation factor IX.
Although the symptoms are equivalent to both sorts of the disease, hemophilia A is far and away from the foremost common.
A handful of biotech companies are now rushing to urge their gene therapies to plug.
Spark, with gene therapy for hemophilia B, and BioMarin, another biotech company, with an identical treatment for hemophilia A, are starting large, final-phase clinical trials.
(Pfizer is taking up the event of the Spark drug.)
Results from the 2 companies’ preliminary trials weren't perfect.
Patients in Biomarin’s hemophilia A trial got, on the average, normal or above normal levels of an antihemophilic factor in their blood, but within the second year, those levels dropped to a median of 46 percent. It’s not clear why.
Patients in Spark’s hemophilia B trial only reached on the average 35 percent of normal blood levels of the Christmas factor.
But those levels have remained steady for the 2 years they need following.
The good news is that those levels are sufficient for blood to clot because normal levels are quite people's need.
After dreaming of a cure for many years, some treated patients try to regulate to newfound freedom.
John Brissette, 39, a person interface designer in Hanover, Mass. said hemophilia A always dominated his life.