Photoimmunotherapy: Treating cancer cells with light now proven to work
Sunday, November 27, 2016
(NaturalNews) A new, experimental, natural treatment modality for cancer
is showing promise.
Developed by Dr. Kerstin Stenson, MD, photoimmunotherapy (PIT) is a technique combining the immune system's ability to target cancer cells precisely with laser energy's abilities to destroy cancer cells. PIT works by delivering a highly precise, lethal dose of energy without causing much damage to healthy cells.
"This treatment is so unique and promising because its cancer cell-killing power is so selective and immediate," said Stenson, director of Rush University Medical Center's Head and Neck Cancer Program, as reported by News Medical Life Sciences
PIT is said to satisfy a basic challenge in beating cancer: Balancing the ability to kill cancer cells while limiting the collateral damage to surrounding tissue. The technique also builds on a current treatment called photodynamic therapy, which is a two-stage procedure beginning with a patient being given an injection of a special drug called a photosensitizer, which is designed to accumulate in and around a cancerous tumor. After that, doctors beam particular wavelengths at the tumor, which causes the absorbed photosensitizer to make a form of oxygen that kills the nearby cancer cells.
'Almost immediately you can see the tumor start dying'
However, in photoimmunotherapy, the photosensitizer is grouped with an antibody produced in the lab called a monoclonal antibody that specifically targets and binds with receptors that are located only on the surface of cancer
cells in the head and neck. The photosensitizer/antibody combo is administered intravenously, and referred to as a "payload drug" that circulates throughout the body, latching only onto head and neck cancer cells
The following day, Stenson places tiny, laser-optic fibers near the surface of the tumor. If it is hard to reach, she will thread the fibers through small catheters directly into the tumor. At that point the laser light
energy is fed through the fibers and strikes the photosensitizer target. The laser energy sets off molecular-level explosions that serve to weaken the walls of cancerous cells, allowing water molecules in surrounding tissue to rush in until cancer cells burst.
"Almost immediately, you can see the tumor start dying," said Stenson. "It turns white and melts away."
And because the payload drug is inert unless and until it is activated by a certain wavelength of light that does not damage human tissue, the destruction of cancer cells takes place with virtually no damage to surrounding cells.
"The drug/dye combination (the monoclonal antibody combined with the photosensitizer) is not toxic until activated by near infrared light, thus is very safe from a systemic perspective," Stenson explained.
'First-class treatment platform'
By contrast, patients who are treated with conventional photodynamic therapy – the predecessor to PIT – have to avoid strong sunlight for several months due to the fact that tiny amounts of photosensitizer remain in their systems and could be activated by the sun, which would cause a major sunburn.
At present, Stenson is leading a clinical trial testing the safety and effectiveness of PIT for patients with head and neck cancer that have not responded to radiation or chemotherapy
, or when surgery is not possible because of the tumor's hard-to-access location.
"Getting inside the cancer cell means we can get systemic treatment locally more than any other treatment," Stenson said. The researcher added that PIT is the most promising and exciting therapy
that she's ever been involved with.
Her study is being sponsored and funded by Aspyrian Therapeutics, the biotech firm company that created the monoclonal antibody conjugate, RM-1929, and obtained the exclusive license for the technology from the National Cancer Institute, developer of the initial photoimmuno therapy.
"Photoimmunotherapy is a first-in-class treatment platform designed to provide an option for patients whose head and neck cancer has failed standard of care treatments," said Merrill Biel, MD, PhD, who set up the PIT clinical trial program and sought out Stenson and Rush to become one of the five sites participating in the study.