Nearly one in ten people are expected to develop a genetic disease as a consequence of carrying defective genes. More than 7,000 distinct rare diseases exist, and approximately 80 percent are caused by faulty genes. And, of the rare diseases, 50 percent of the people affected are children, making rare diseases one of the most debilitating for children worldwide.
This focus on curing diseases via the use of what is called “gene therapy” has evolved into of the most exciting developments in medical research. By correcting an underlying genetic defect, gene therapy can provide for transformative effects based on only a single treatment.
What is gene therapy? In the simplest terms, gene therapy involves the replacement of a gene that is defective. The process involves the packaging of a functioning copy of the defective gene into a viral vector. This vector is based on a naturally occurring virus (such as HIV), which has been modified so that the virus cannot spread within the person’s body. A virus has a natural ability to introduce genes into human cells, and thus, its role in the delivery of the gene is critical in the gene therapy process. This vector acts as the delivery mechanism for transporting the functioning gene into the blood stem cells taken from the patient. Rather than offering solutions that only address a patient’s symptoms, gene therapy corrects the underlying genetic defect that is the actual cause of the disease.
The first out-and-out-cure: During 2016, Italian scientists at Milan’s San Raffaele Telethon Institute for Gene Therapy reported that they had cured 18 children of a rare but terrible immune deficiency disease, ADA-SCID. They removed the children’s bone marrow, added a gene to make the ADA enzyme their bodies lack, and replaced it. It took 14 years to develop and test and was approved in May of last year in Europe.
Rewiring the Eye: RetroSense, a company that was quickly acquired by Allergan (AGN) for $60 million is currently injecting genes from light-sensing algae into the eyes of a blind person. This was the first time a whole gene from a different species had been used in a human being. It was also the first test in a human of optogenetics, the technique of using light and gene therapy to control nerve cells.
From Gene Replacement to Gene Editing: Today’s gene therapy is about adding genes, to replace one in your body that isn’t working. Gene editing could be a way to erase such diseases, with a one-time, permanent alteration of a person’s DNA. A scientific resolute, known as the CRISPR technique is often likened to a “search and replace” function for DNA.
It’s a step beyond conventional gene therapy— The gene for dystrophin, for instance, is too large to fit inside a virus, as CRISPR’s DNA-snipping proteins can. And sometimes a faulty gene that’s doing harm needs to be silenced, so adding a new one won’t help. CRISPR’s ability to delete and swap out genetic letters makes a huge new range of treatments possible. Some doctors are now calling CRISPR “gene therapy 2.0.”
In early-stage lab experiments, academic scientists are showing that gene editing offers new ways to attack cancer, to knock out HIV and hepatitis infections, even to reverse blindness and deafness. Companies aren’t far behind. Three startups in the Boston area have already raised a combined $1 billion and partnered with some of the world’s biggest drug companies, like Bayer (BAYN) and Novartis (NVS).
CAR T-cell therapy in cancer: Another exciting development in gene therapy involves the use of the patient’s own immune system to fight off cancer. Known as CAR T-cell therapy, the process involves genetically engineering a patient’s T cells outside the body to produce special receptors called chimeric antigen receptors (CARs). Thus far, there has been tremendous progress made with CAR T-cell therapy as it relates to treating blood cancers. Because of this, many of the bigger biotech companies have been scrambling to partner with specialists in the space. Celgene (CELG) announced a $1 billion deal with Juno Therapeutics (JUNO) to collaborate on several CAR T-cell cancer therapies. The big question is whether or not the early indications for success in blood cancer can translate to successful treatment of solid tumors.
The optimism is based not only on the game-changing potential for the related therapies, but also for the need of big biotechnology companies to diversify their portfolios and how this could lead to more M&A activity in the space. .
Although the gene therapy field has had its share of ups and downs, this once-questionable method of treating diseases now seemingly has the potential to become one of the most game-changing advancements in medical history.