In one of the biggest advances against leukemia and other blood cancers in many years, doctors are reporting unprecedented success by using gene therapy to transform patients’ blood cells into soldiers that seek and destroy cancer.
A few patients with one type of leukemia were given this one-time, experimental therapy several years ago and some remain cancer-free today. Now, at least six research groups have treated more than 120 patients with many types of blood and bone marrow cancers, with stunning results.
"It’s really exciting," said Dr. Janis Abkowitz, blood diseases chief at the University of Washington in Seattle and president of the American Society of Hematology. "You can take a cell that belongs to a patient and engineer it to be an attack cell."
"What we are giving essentially is a living drug"—permanently altered cells that multiply in the body into an army to fight the cancer, said Dr. David Porter, a University of Pennsylvania scientist who led one study.
Several drug and biotech companies are developing these therapies. Penn has patented its method and licensed it to Switzerland-based Novartis AG. The company is building a research center on the Penn campus in Philadelphia and plans a clinical trial next year that could lead to federal approval of the treatment as soon as 2016.
The gene therapy must be made individually for each patient, and lab costs now are about $25,000, without a profit margin. That’s still less than many drugs to treat these diseases and far less than a transplant.
The treatment can cause severe flu-like symptoms and other side effects, but these have been reversible and temporary, doctors say.
Penn doctors have treated the most cases so far—59. Of the first 14 patients with CLL, four had complete remissions, four had partial ones and the rest did not respond. However, some partial responders continue to see their cancer shrink a year after treatment.
"That’s very unique to this kind of therapy" and gives hope the treatment may still purge the cancer, said Porter. Another 18 CLL patients were treated and half have responded so far.
Penn doctors also treated 27 ALL patients. All five adults and 19 of the 22 children had complete remissions, an “extraordinarily high” success rate, said Dr. Stephan Grupp at the Children’s Hospital of Philadelphia.
Six have since relapsed, though, and doctors are pondering a second gene therapy attempt.