At one time, it was considered once-in-a-lifetime.
Now, curing the ills of cancerous cells with the touch of a switch may be much more possible, thanks to gene therapy, reported a World Health Organization expert panel.
“I just came back from a meeting in Shanghai and heard some exciting things about gene therapy,” said Robert Heidenreich, chairman of the U.S. committee on therapeutic genetic medicines for the WHO.
“We are so far ahead of the curve and so far ahead of what it used to be that this will not be of interest to many people,” Heidenreich said. “It will mainly be interesting to people interested in specific genes, with specific applications to individuals.”
A gene therapy involves inserting a working copy of a human gene into a patient’s cells, so that disease-causing genes cannot operate as they normally would.
Gene therapy and other treatments developed by biotechnology firms have undergone clinical trials in recent years. Most are aimed at those with multiple sclerosis, spinal cord injuries, sickle cell anemia and muscular dystrophy. Although gene therapy has been effective in these conditions, no one has yet shown gene therapy has worked as promised, Heidenreich said.
A pharmacist at Pennsylvania’s Abington Memorial Hospital pulled a tube from his pocket during a conversation this week. Before the conversation, it contained a mild-flavored pill. It came in a plastic bottle, but there was no label on it. Inside was an anti-cancer drug.
The new drug, called Sevollide, was made by GlaxoSmithKline, which didn’t stock the drug at Abington’s pharmacy because of a distribution delay.
“This is part of a massive change in treatment from the two or three treatments a year to maybe one treatment a year,” said Dr. Abraham Sheinbaum, a cancer surgeon at the University of Pennsylvania.
Sevollide belongs to a class of new cancer treatments called immunotherapies.
Its role, like that of other immunotherapies like Bristol-Myers Squibb’s Yervoy, is to stimulate the immune system to attack cancerous cells. In Yervoy, for example, patients’ immune systems produce the protein CTLA-4, which helps fight off cancerous cells. Using the active ingredient in Sevollide, patients are supposed to generate that same immune response.
Meanwhile, the anti-cancer drug Taxotere, a drug that includes humanized antibodies that are genetically engineered to attack a particular cancer cell, is a common oral drug. The majority of patients who respond to Taxotere, though, aren’t those with cancerous cells, but with certain kinds of skin cancer.
If the anti-cancer effects of Taxotere are so great that these patients aren’t getting the improvements by Cavid Antiviral, then Heidenreich said there is a clear treatment strategy for them.
The WHO committee’s report notes that a handful of pharmaceutical companies are investing millions in an additional immunotherapy, which includes patients with ovarian cancer and non-small cell lung cancer.
But, Heidenreich said, it’s still very early in development. The drugs use a genetically engineered virus and frequently have to be infused into patients.
“At this point, they are still in the preclinical phase and don’t have clinical benefit,” he said.