A North Vancouver boy struggling with a rare genetic disease will finally receive the treatment he needs on Canadian soil.
Nine-year old Trey Purcell was the only Canadian travelling to North Carolina with his parents to receive the drug therapy he needs to battle his MPS II, or Hunter Syndrome. But as of July 22, he will get his 23rd dose of the therapy at B.C. Children's Hospital.
Hunter Syndrome, primarily found in boys, is caused when sugar chains in the body are not properly broken down due to a missing enzyme. The fragmented chains progressively cause damage in the body. Symptoms do not show until at least two years of age and can include a large head (hydrocephalus), enlarged tongue and organs,
and hearing loss, to name a few. For Trey's mother Deb Purcell, moving the treatment to Vancouver was a big relief.
"It's a lot less stress logistically," said Purcell, who together with her husband has had to take time off work for Trey's treatment, resulting in some financial burden.
Purcell, who has two other children, said the biggest issue was getting the replacement drugs in the first place. The family faced an uphill battle to get Trey's very first treatment, which he received in February 2007.
"At least now we're getting drugs," she said. "But this has put a huge strain on our entire family."
Trey receives an intravenous enzyme replacement therapy four hours a week at home, which is administered by Purcell. The treatment stops the progressive disease in the body, said Purcell, but it can't cross the blood brain barrier and therefore cannot halt the disease in the brain. But with the phase I/II drug trial, which Trey started in October 2011, the enzyme is administered differently.
"They put it into the central nervous system and brain," said Purcell.
Although Trey hasn't had any noticeable side effects with the drug, there are risks. For the treatment, Trey has to be put under general anesthetic and receives a lumbar puncture, which is a needle that is injected into the base of the spine. But for Purcell, the risk is worth it.
"If he hadn't been getting this he would have been moving towards death," said Purcell.
Purcell said without the drugs, Trey would have gradually lost skills, such as language, and eventually would have suffered seizures and been unable to eat.
"We would have been en route to that instead of a kid who is telling me he wants a girlfriend and deciding what sports he wants to play in the fall," said Purcell.
The phase I/II trial was to ensure the safety of the drug and was only at two trial sites, one through the University of North Carolina and the other at Birmingham Children's hospital in the UK. Since the drug has been deemed safe, a phase II/III trial will begin in September. Trey will not be a part of the second trial, but will remain on an extension study of the phase I/II trial.
Purcell said Trey has been taking the treatments in stride, including having the general anesthetic.
"He handles it a lot better than a lot of other kids," she said. "Trey puts the mask on himself."
Hunter Syndrome is extremely rare and according to the MPS Society only affects 1 in 100,000 to 1 in 150,000 males. There is no cure, but Purcell has advice for any family with a child who has been diagnosed with a rare disease. "You are your child's best advocate," she said. "It's having confidence that you know what's best for your child."
