Photodynamic Therapy (PDT)
PDT is a treatment that uses light sensitive compounds, or photosensitizers, that, when exposed to specific wavelengths of light, act as a catalyst to produce a form of oxygen that induces local tumor cell death. This form of oxygen is known as reactive oxygen species or ROS.
ROS can initiate various biological mechanisms of action that are known to be effective against tumors
PDT can induce elimination of diseased cells by immune response, apoptosis, antiangiogenesis and necrosis
REM-001 Therapy as a Potential Immunotherapy
It has been well known for some time that PDT, including REM-001, can induce tumor death by apoptosis, necrosis or vascular shutdown. In fact, the most early applications of PDT were based on preclinical research that had established the dosing schemes necessary to induce one or more of these effects. However, PDT's ability to induce an immune T-cell response was not recognized until much later. There is ongoing preclinical work that has demonstrated that PDT can provide a highly promising tumor immune response in animal cancer models and we anticipate this work may lead to clinical applications of PDT in a role as an immunotherapy. One possibility is the use of PDT to induce the release of tumor specific antigens that stimulate dendritic cells, thereby activating the body's immune response to attack metastatic tumor cells. As our development of REM-001 Therapy in the treatment of cutaneous cancers progresses, we anticipate we will be well positioned for potential further clinical development of our therapy as a key element in an immunotherapy regimen.
In the case of cutaneous treatment, our light delivery device is a wand that consists of an optical fiber with one end connected to the laser and the other end modified to allow it to be easily positioned to deliver a uniform light treatment field to the tumor. For internal cancers, PDT uses a light delivery medical catheter that contains an optical diffuser. Here again, one end is connected to the laser light source, but the catheter diffuses this light to illuminate the tumor.
The lead program in our development plan for REM-001 Therapy is cutaneous metastatic breast cancer. Our plan is to make significant progress toward marketing approval in that indication and then expand our development into other indications.