“That’s very unique to this kind of therapy” and gives hope the treatment may still purge the cancer, Porter said.
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 Stephan Grupp at the Children’s Hospital of Philadelphia.
Six have since relapsed, though, and doctors are pondering a second gene therapy attempt.
At the National Cancer Institute, James Kochenderfer and others have treated 11 patients with lymphoma and four with CLL, starting roughly two years ago. Six had complete remissions, six had partial ones, one has stable disease and it is too soon to tell for the rest.
Ten other patients were given gene therapy to try to kill leukemia or lymphoma remaining after bone marrow transplants. These patients got infusions of gene-treated blood cells from their transplant donors instead of using their own blood cells. One had a complete remission and three others had significant reduction of their disease.