A Life-changing Genetic Cure for Sickle Cell Patient

Sickle cell disease occurs in people who inherit two copies of the sickle cell gene, one from each parent. This produces abnormal haemoglobin, called haemoglobin S. Credit: Darryl Leja, National Human Genome Research Institute, National Institutes of Health

Jimi Olaghere, who had suffered all his life from the chronic pain of sickle cell disease, recently received a genetic cure decades sooner than he would have believed possible.

Mr Olaghere is one of the first seven sickle cell patients who received a new gene-editing treatment going through its first clinic trials in the US. “It’s like being born again,” he said, adding that it has changed his life. “When I look back, it’s like, ‘Wow, I can’t believe I lived with that.'”

Mr Olaghere, 36 said: “You always have to be in a war mindset, knowing that your days are going to be filled with challenges.”

Sickle cell disease is caused by a mutated gene that results in abnormal haemoglobin, leading to blood cells becoming more rigid and taking on their characteristic sickle shape. These malformed cells often get stuck in blood vessels, giving rise to ischaemias and an increase in cardiovascular disease risk and organ damage. Mr Olaghere may need a hip replacement due to avascular necrosis.

The disease also causes chronic pain, which he likened to “shards of glass flowing through your veins or someone taking a hammer to your joints.”

Severe pain episodes known as crises are the hallmark of sickle cell disease. For years, Mr Olaghere was hospitalised on a monthly basis. Winters worsened the problem as the cold restricted surface blood vessels, increasing the risk of blockages. He moved to a warmer city, and became a tech entrepreneur as he didn’t think any employer would be sympathetic to going to the hospital so often.

His family urged him to participate in clinical trials or receive a bone marrow transplant. However, he thought it would take too much time and instead pinned his hopes on DNA editing “in the future, probably 20 to 50 years from now”.

But in 2019 he read about a new gene editing therapy and emailed the medical team right away. When he learned he was accepted, he said it was “the best Christmas present ever”. As the pandemic hit and flights were cancelled, he was still able to make the four-hour drive for treatment appointments.
In order to genetically edit his stem cells the stem cells were flushed out of his bone marrow and into the bloodstream for collection.

“You sit there for eight hours and this machine is literally just sucking all the blood out of you,” he said.

The process left him physically and mentally drained, and still needed  blood transfusions. Mr Olaghere had to go through this process, the most difficult of all for him, four times. 

The key to the treatment lies not in correcting the genetic defect that produces the cell but rather sidestepping it by getting the body to use an alternative: foetal haemoglobin 

Ordinarily, at around 40 weeks of pregnancy, a genetic switch called BCL11A is flipped and the body starts producing adult haemoglobin – which is the only form affected by sickle cell disease. 

“Our approach is to turn that switch off and increase the production of foetal haemoglobin again, basically turning the clock back,” explained Dr Haydar Frangoul, who treated Mr at the Sarah Cannon Research Institute.

Mr Olaghere’s stem cells were sent to Vertex Pharmaceuticals’ laboratories for genetic editing. By September 2020, the engineered cells were ready to be infused into his body. “It was the week of my birthday, actually. So it was almost like getting a new life,” he recalled.

The original faulty stem cells that remained in his body were killed off with chemotherapy, and then genetically engineered replacements were infused into his body to produce sickle-free blood.

“I remember waking up without any pain and feeling lost,” he said. “Because my life is so associated with pain, it’s just a part of who I am. It’s weird now that I don’t experience it any more.'”

Dr Frangoul said that the first seven patients’ results have been “nothing short of amazing” and represented a “functional cure” for their disease.
“What we are seeing is patients are going back to their normal life, none have required admission to hospital or doctor visits because of sickle cell related complications,” Dr Frangoul said.

So far, the genetic technique has been conducted on 45 patients with either sickle cell disease or beta thalassaemia. However, the data are still being gathered.

Source: BBC News