Q: What is Benzoporphyrin Derivative - MonoAcid Ring A (BPD verteporfin)?
A: BPD verteporfin is a drug that is derived from animal hemoglobin. Hemoglobin is the part of red blood cells that carries oxygen. Early tests with this drug have shown promising results when used in Photodynamic Therapy (PDT) for the treatment of cancer or psoriasis. BPD verteporfin is being tested in Clinical Trials in Vancouver, BC, Canada.
Q: What is Photodynamic Therapy (PDT)?
A: PDT is a treatment that uses light to activate light-sensitive drugs such as BPD verteporfin. For BPD verteporfin, visible red light or Ultraviolet A (UVA) light is used.
Q: What are Clinical Trials?
A: Clinical Trials are used to evaluate the use of new drugs in humans. Before a drug reaches testing in Clinical Trials, it is first evaluated for safety in animals. During Clinical Trials, the safety and effectiveness of a new drug are assessed in patients under close medical supervision.
Q: Why is BPD verteporfin used in Photodynamic Therapy?
A: Animal studies have shown that the effects of BPD verteporfin occur only in the presence of light because BPD verteporfin is light sensitive. It captures energy from light and uses this energy to produce toxic reactions in surrounding tissues. Without light, BPD verteporfin has little effect.
Q: How will BPD verteporfin and PDT affect psoriasis?
A: BPD verteporfin is given intravenously (I.V.) and is distributed throughout the body by the blood. The drug accumulates in all tissues, but abnormal tissues such as psoriatic plaques accumulate even more. Psoriasis may be improved when light (either red or UVA) is shone onto a plaque because toxic reactions only occur where there is sufficient BPD verteporfin and light.
Q: What sequence of events occur when a patient is treated with BPD verteporfin and light?
A: Patients are admitted as out-patients to the Skin Care Centre in Vancouver in the morning. There, they receive a brief I.V. infusion of BPD verteporfin. A short while later, patients receive treatment with red or UVA light that is shone directly onto selected areas of psoriasis. Once the psoriasis has been exposed to light, the treatment is completed. Patients are discharged in the afternoon.
Note: During treatment, patients wear protective goggles to protect eye-sight from exposure to UVA or bright red light.
Q: What side effects are expected with BPD verteporfin and light?
A: The patient consent-form details all possible side effects. However, two side effects are common and expected:
Q: Are any tests required?
A: Yes, any or all of the following tests may be performed:
Q: What happens to the plaque after it has been treated?
A: Some patients have experienced clearing of their plaques as soon as a few weeks after beginning treatment. However, a range of light and drug doses may be used in any given study, so results will vary. In cases where higher doses of BPD verteporfin or light are used, the psoriatic plaque and some surrounding tissue may become pale and/or reddened. Later, bruising may become apparent. A scab (or crust) could also form over the plaque. If a scab does form, healing will take place within 4-6 weeks. In other situations, no reactions or clearing of the plaques occur.
Q: How often does a patient need to return for follow-up visits?
A: Follow up visits vary study to study. In general, patients need to return for brief examinations up to two to four weeks after the final treatment with BPD verteporfin.
Q: Where is the Skin Care Centre located?
A: Next to Vancouver Hospital -
Q: What about parking?
A: There is meter parking on the street, or coin parking (quarters or loonies) in our underground parking lot.
Q: What should a patient do if he or she has any questions or concerns?
A: Call Mike Gagel at +1 (604) 875-5254 at the Skin Care Centre (Photodermatology Research). This telephone local is connected to voice mail. If there is a more urgent inquiry, patients can contact Dr. Harvey Lui at +1 (604) 875-4682.
Created: 10Dec95. Revised: 16Apr97.