An experimental therapy giving one young man a second chance by wiping out the disease
HACKENSACK, N.J. — For thousands, it’s difficult to lead a normal life with the diagnosis of sickle cell disease.
Sickle cell disease causes red blood cells to form the shape of a sickle, making it difficult for blood to flow.
Doctors are testing an experimental therapy that could be life-saving for patients running out of treatment options.
It came just in time for 19-year old Razel Colon.
He’s lived his entire childhood knowing the slightest wrong move could cause him terrible pain or put him in danger.
“It was scary when I used to play outside with my friends and a football would hit me in the chest, knowing that I had sickle cell that could transfer over to a heart attack or stroke,” he said.
Razel was diagnosed with sickle cell disease at three months.
As he grew older, pain crises meant living in the hospital for days and weeks at a time.
“It’s really hard for a parent because there’s nothing you can do to help your child,” his mother Kyelia remembered.
Doctors suggested Razel undergo a bone marrow transplant, but no one in his family was a match.
That’s when doctors suggested a new, experimental gene therapy.
“So gene therapy was engineered, so that the patient could be their own donor,” explained Dr. Stacey Rifkin-Zenenberg, a pediatric hematologist at New Jersey’s Joseph Sanzari Children’s Hospital.
During the gene therapy procedure, doctors remove a patient’s bone marrow with chemotherapy.
The patient’s harvested stem cells are sent to a lab, where a gene is added.
“Then we give them back their own stem cells with the added gene,” said Dr. Rifkin-Zenenberg
The body begins to produce healthy red blood cells.
The process takes about a month.
For Razel, the gene therapy all but wiped out the disease.
He is still a carrier of sickle cell, but no longer has pain crises.
“It’s amazing because he gets to live a normal life, which he didn’t live before,” said Kyelia.
Scientists have since determined the cancer was not linked to the sickle cell treatment and have asked the FDA for permission to resume the trial.
The researchers are hoping to apply to the FDA for approval next year.
Research shows the reason gene therapy is critical for sickle-cell patients is that the gene mutation causing the disease is on the adult hemoglobin gene, not the fetal hemoglobin.
Gene therapy in sickle cell works by knocking down the manifestation of the BCL11A gene to reverse it back to fetal hemoglobin.
This increases fetal hemoglobin, which does not sickle, and directly reduces sickling.
A patient’s blood stem cells are collected and exposed to a path containing instructions to knock down BCL11A.
The patient then receives chemotherapy in a process called conditioning, which is similar to plowing a field to make room for new seeds.
Finally, the gene-modified cells are given back via intravenous infusion.
It’s taught Razel a valuable lesson.
“Don’t give up and there’s hope.”