The first attempt in the United States to use the CRISPR cancer gene editing tool seems safe in the three patients who have had it so far, but it is too early to know if treatment will improve survival, doctors said on Wednesday.
Doctors were able to remove immune cells from patients' blood and genetically alter them to help them recognize and fight cancer, with minimal and manageable side effects.
Treatment excludes three genes that may be impairing the ability of these cells to attack the disease. T also adds a new fourth feature to help them get the job done.
"It's the most complicated genetic cell engineering that has been tried so far," he said. Dr. Edward Stadtmauer University of Pennsylvania, Philadelphia, which leads the clinical trial. "This is proof that we can safely perform genetic editing of these cells."
After two to three months, one patient's cancer continued to worsen and another patient was stable. The third patient was treated very recently to find out how she will fare. The plan is to treat 15 more patients and evaluate the safety and how well it works.
"It's too early, but I'm incredibly encouraged by that," he said. Dr. Aaron Gerds, a cancer specialist at the Cleveland Clinic who is not involved in the trial.
Other cell therapies for some types of blood cancer "have been a huge success, catching incurable diseases and curing them," and gene editing may provide a way to improve that, Gerds said.
Gene editing is a way of permanently altering DNA to attack the causes of a disease. CRISPR is a tool for cutting DNA at a specific location. It has long been used in the laboratory and is being tested for other diseases.
This study is not intended to alter DNA in a person's body. Instead, it seeks to remove, alter, and return the patient's superpowered cells to fight cancer – a form of immunotherapy.
Chinese scientists I would have tried this on cancer patients, but this is the first study outside of China. It is so new that it took more than two years to get the approval of US government regulators to try it out.
Early results were released by the American Society of Hematology; Details will be provided at your annual conference in December.
Two of the patients have a blood cancer called multiple myeloma and the third has a sarcoma, cancer that forms in the connective or soft tissue. All three had failed several standard treatments and were without good options.
Their blood was filtered to remove soldiers from the immune system called T cells, which were modified in the lab and then returned to patients via IV. It is intended as a unique treatment. The cells must multiply in an army within the body and act like a living drug.
So far, the cells have survived and multiplied as intended, Stadtmauer said.
"This is a totally new therapy," so it's not clear how long these patients will need to be followed and tested to detect any anticancer effects, he said.
The study is sponsored by the University of Pennsylvania, the Parker Institute for Cancer Immunotherapy in San Francisco, and a biotechnology company, Tmunity Therapeutics. Several study leaders and the university have financial stakes in the company and may benefit from technology patents and licenses.