The Medical College of Wisconsin is testing a laser-activated photosensitive dye as a new treatment for aggressive brain and spinal cord tumors. MCW has begun a Phase II trial of Photofrin and photodynamic therapy in adult patients at Froedtert Hospital, a protocol funded by Ontario-based Concordia Healthcare Corp.
The therapy consists of a two-step treatment process in which Photofrin, a photosensitizing drug, is injected into the blood stream and accumulates in cancer cells. Next, a laser light activates the drug, which then directly attacks cancer cells. Additionally, the laser light itself damages the blood vessels feeding the tumor.
“Patients with high-grade gliomas in particular have a very poor prognosis,” said the study’s lead investigator Dr. Harry Whelan. “Photodynamic therapy with Photofrin has the potential to add to the multi-modal approach of surgery and chemotherapy by providing another treatment option for patients with rare cancers for which there is no clear standard of care.”
The MCW study will evaluate the effect of Photofrin on 30 glioma brain tumor patients. Everyone in the study will receive Photofrin (porfimer sodium) for injection and be treated with red light emitted by a red laser. The light will be sent from the laser to the surface of the brain where the tumor is located using a light transmitting fiber. The fiber will have a tiny knob at the end that spreads the light out evenly in all directions.
Previous studies have shown that patients with malignant brain tumors called gliomas had a good response to PDT. The patients in these studies lived longer than they were expected to live. In one study of adults with brain tumors in Australia, patients given PDT had greatly improved survival rates. For instance, 57 percent of the patients with gliomas called anaplastic astrocytoma survived for 36 months, and 37 percent of the patients with gliomas called glioblastoma multiforme survived for 36 months.
Whelan also is conducting a Phase 1 clinical trial of PDT with Photofrin in children and adolescents, from newborn to 18 years old, who have recurrent or progressive brain tumors. The trial is being conducted by the Children’s Hospital of Wisconsin Research Institute and MCW.
Whelan is the Bleser Professor of Neurology and Pediatrics and Hyperbaric Medicine at MCW and an investigator at the Children’s Hospital of Wisconsin Research Institute.