A new treatment for blindness has brought gene therapy into the real world, but it comes with a large price tag. Share on Pinterest Gene therapy has finally moved out of the realm of science fiction… and this time, it may be here to stay. But with price tags edging toward the million-dollar mark, will anyone but the mega-wealthy be able to afford these new treatments? Last month , the Food and Drug Administration (FDA) approved a new gene therapy treatment for a rare, inherited form of blindness. The cost? $850,000 — lower than the $1 million that many analysts expected. Still, that’s $425,000 per eye. For a drug that doesn’t fully restore vision. And that’s only known to work for up to four years in some patients. Only around 1,000 to 2,000 people in the United States may benefit from this one-time treatment. Like other super-expensive treatments for uncommon diseases, the rarity of this disorder partially explains its high cost. People with this condition have a particular gene, known as RPE65, that causes their vision to deteriorate. In some people, it may cause complete blindness. The drug, called Luxturna, was developed by Philadelphia-based Spark Therapeutics. As the manufacturer and insurance companies wrestle with how to make this drug affordable while allowing the company to still turn a profit, the gene therapy field continues to move ahead.

Treatments on the horizon What happens in 2018 for gene therapy will build on what scientists and drug companies accomplished last year. “Some of the more exciting developments last year concerned successful product development and pricing in the commercial arena. I expect that to move forward some more,” said Dr. Sanjeev Gupta, a professor of medicine and pathology at Albert Einstein College of Medicine and Montefiore Health System. In the cancer arena, the FDA approved CAR T-cell therapy for certain children and young adults with one type of acute lymphoblastic leukemia (ALL). This type of immunotherapy involves genetically modifying a person’s immune cells — T cells — to boost their ability to attack cancer. The FDA also approved a CAR T-cell therapy for the treatment of a type of B-cell lymphoma that occurs in adults. With scientists achieving this “major progress in treating cancers [that occur in the blood],” Gupta said “we’ll hopefully see more such progress for solid tumors.” Another area that will continue to see progress is gene editing, the ability to make precise changes in a cell’s DNA sequence. “Gene editing with CRISPR technologies is becoming more and more exciting,” Gupta told Healthline. “Several companies are competing in gene editing — the Sangamo trial for Hunter syndrome was an early example — but we’ll be seeing more trials of gene editing.” CRISPR-Cas9 is a genome editing tool that allows scientists to add, remove, or alter specific sections of DNA, not just in people but in other organisms as well. Scientists at Harvard University recently used this technique to slow a progressive form of deafness in mice. The genetic mutation that causes this condition also occurs in people, although only in a small number of families — so it may not be long before scientists try this treatment in people. Another area that Gupta expects to see developments in the near future is gene expression regulation. Being able to control which genes are active may give scientists a way to treat diseases without having to alter the DNA.

Diseases ripe for gene therapy While any disease is a potential target for gene therapy, some treatments are easier to achieve in the clinic. It’s no coincidence that one of the first gene therapies approved by the FDA is a treatment for blindness. “Eye conditions are amenable to gene therapy for various reasons,” said Gupta, “including easy access to the eye and treatment outcomes that are more readily evaluated than in some other cases.” More complex genetic diseases, such as Hunter syndrome, involve multiple organ systems and the damage occurs deeper inside the body than the eye. Blood diseases are also easier targets because blood cells can be removed, genetically modified, and then put back into a person’s body. This includes the leukemia treated by the recently approved CAR T-cell therapy. But there are other potential treatments. “Hemophilia A and B are major targets that many companies are actively pursuing,” said Gupta. Hemophilia is a genetic disorder that impairs the blood’s ability to clot. “Also, we should see developments in sickle cell disease or beta thalassemia,” added Gupta, “where discrete mutations may be edited to correct abnormal hemoglobin production that causes rapid destruction of red blood cells and anemia.” Gupta thinks muscular dystrophy may be another major target for gene therapy in the near future.