Toronto-based biotech Theralase Technologies has developed a novel approach to cancer treatment. Laser therapy is generally associated with chronic pain management, but the company is pushing in new directions with the development of its Photo Dynamic Therapy (PDT), an alternative therapy for cancer that combines laser with drugs. Last year, Theralase announced it had achieved near complete destruction of bladder cancer in an animal model, and is now working with the Princess Margaret Cancer Centre, the number three cancer treatment institute globally, to conduct clinical trials.
“Uro-oncologists are very interested in our early stage technology and animal studies, and now they want to see data on human patients,” says Roger Dumoulin-White (pictured), president & CEO at Theralase.
PDT is a form of phototherapy used to destroy cancer cells, explains Dumoulin-White. Nontoxic light-sensitive compounds, known as Photo Dynamic Compounds (PDCs) possess the ability to selectively accumulate in cancer cells versus healthy cells and when exposed to specific wavelengths of laser light, they produce a destructive form of oxygen known as Reactive Oxygen Species (ROS), which can destroy these cancer cells through apoptosis – natural cell death.
Each PDC is designed to be activated by laser light of a specific wavelength. These wavelengths then determine how far the laser light can travel into tissue and hence how deep in the body the PDC can be activated to provide patient-specific PDT.
Dumoulin-White says, “Theralase has developed and patented custom PDCs – small molecules that are benign until they’re activated by laser light. These PDCs have an affinity for cancer cells and are able to penetrate cancer cell walls locking onto organelles such as the mitochondria and endoplasmic reticulum. Once targeted by the PDCs, these cancer cells can then be selectively destroyed when they’re exposed to the right wavelengths and dosages of laser light.”
“By having these compounds localize in cancer cells and not in healthy cells, we can light-activate them to destroy the cancer cells from the inside out, and allow the body to dispose of them through normal cellular processes. With our PDT protocol, the patient literally urinates out their destroyed bladder cancer within days.”
PDT would be applicable to 50 percent of patients with bladder cancer (ie. those who have relapsed within 2 years of treatment). In this form of treatment, Theralase’s lead water-soluble PDC, TLD-1433, is instilled into the bladder via a catheter, allowed to absorb into bladder cancer cells for approximately 60 minutes and then laser light-activated over a period of approximately 30 minutes. The entire procedure could be performed in a surgical suite in less than three hours from beginning to end.
PDT has been used successfully in animal studies to destroy different types of cancer cells – colon, breast, brain, lung, pancreatic and so on – and not just bladder cancer, adds Dumoulin-White.
Bladder cancer was selected for the human trials at Princess Margaret because it’s particularly amenable to PDT. “In PDT, you want to get the compound to the tumors and have it absorbed, and with the activation, you want to put the light source fairly close to it. The reason we chose Non-Muscle Invasive Bladder Cancer (NMIBC) was simply that we had an easy access to the organ into the body, non-surgically. It’s very easy to instill liquids into the bladder through a catheter.”
PDT could also be tested on breast cancer, but that would be more challenging. “It would need a systemic injection of compounds, and then you’d either have to illuminate through the breast, or you’d have to go through a milk duct via visual guidance, such as diagnostic ultrasound.”
In animal studies, Dumoulin-White says PDT destroyed almost all cancer cells after just one treatment. “This is usually a one-shot deal, but if there’s a recurrence of cancer, there’s no reason you can’t have the treatment again. Unlike radiation, PDT can be repeated as many times at the same site, as required, costing less than most other cancer treatments.”
The medical community has been skeptical of laser therapy for many years – and rightly so, says Dumoulin-White. “What you see if you look at studies of Low-Level Laser Therapy is a wide range of results across different types of patients. Sometimes it’s very effective, sometimes it’s so-so, and sometimes it’s not effective at all. Theralase has solved these problems with our next generation of medical laser technology.”
After labouring for years, Dumoulin-White says his researchers and engineers have finally found the most effective forms of laser therapy. “Light can be a powerful drug, but you have to use it at the right wavelengths and dosages for optimal results. Our technology works consistently and effectively on all types of patients.”
For more information, visit http://theralase.com/anticancer-technology/