Gene therapy cure for blindness, type I diabetes, advanced HIV

Scientists have in recent studies advanced the use of gene therapy as cure for Human Immuno-deficiency Virus (HIV), type I diabetes and blindness.

The results of a new study published in the December 28 issue of the journal PLOS Pathogens suggest that gene therapy may have the potential to eradicate HIV in people infected with the virus.

The researchers reported that the science centers around the use of “chimeric antigen receptor” (CAR) genes. In laboratory work with monkeys, these engineered cells have destroyed HIV-infected cells for more than two years.

Scientists have been searching for a way to create long-term immunity to HIV, the Acquired Immune Deficiency Syndrome (AIDS)-causing virus. Currently, antiretroviral therapy is prescribed to keep HIV under control, but this does not eliminate the virus from the body.

Study co-author Scott Kitchen, of the University of California, Los Angeles, School of Medicine, United States (U.S.), said: “Theoretically, the goal is to provide a lifelong immunity to HIV. We’re aiming for a cure,” he said. “And we know that to cure HIV you need an effective immune response, which is what we’re seeing here.”

Kitchen is an associate professor of medicine with the division of hematology and oncology.

Also, another new study, published January 4, 2018 in journal Cell Stem Cell, has demonstrated that a gene therapy approach can lead to the long-term survival of functional beta cells as well as normal blood glucose levels for an extended period of time in mice with type 1 diabetes. The researchers used an adeno-associated viral (AAV) vector to deliver to the mouse pancreas two proteins, Pdx1 and MafA, which reprogrammed plentiful alpha cells into functional, insulin-producing beta cells.

Type 1 diabetes is a chronic disease in which the immune system attacks and destroys insulin-producing beta cells in the pancreas, resulting in high blood levels of glucose.

Senior study author George Gittes of the University of Pittsburgh School of Medicine, US, said: “This study is essentially the first description of a clinically translatable, simple single intervention in autoimmune diabetes that leads to normal blood sugars, and importantly with no immunosuppression.

“A clinical trial in both type 1 and type 2 diabetics in the immediate foreseeable future is quite realistic, given the impressive nature of the reversal of the diabetes, along with the feasibility in patients to do AAV gene therapy.”

Also, the United States Food and Drug Administration (FDA) approved the first gene therapy for a rare inherited form of blindness affecting between 1,000 and 2,000 Americans last month.

A first-of-its kind genetic treatment for blindness will cost $850,000, less than the $1 million price tag that had been expected, but it’s still among the most expensive genetic therapies in the world.

The new therapy was approved last month to treat a rare genetic mutation that causes blindness in between 1,000 and 2,000 people in the US.

Spark Therapeutics, which makes the drug, says it decided on the lower price tag for Luxturna after hearing concerns from health insurers about their ability to cover the injectable treatment.

Consternation over skyrocketing drug prices, especially in the US, has led to intense scrutiny from patients, Congress, insurers and hospitals.
Luxturna is an injection – one for each eye – that replaces a defective gene in the retina, tissue at the back of the eye that converts light into electric signals that produce vision. The therapy will cost $425,000 per injection.

The treatment is part of an emerging field of medicine that could produce dozens of new gene-targeting medications in the next few years.

There are questions about the wisdom of devoting so much energy to specialty drugs, which are used to treat so few people, but still account for a growing slice of overall health care costs.

Drug-makers have historically offered little explanation for the prices they charge. However, some companies have begun to offer more detailed reasoning as the backlash against drug prices has grown more heated.

Spark Therapeutics, based in Philadelphia, has said that the cost for a lifetime of blindness – including lost earnings and caregiver wages – can easily exceed $1 million.