BBI Contributing Editor

Photodynamic therapy (PDT) encompasses a wide range of treatments that involve the combination of light and a photo-active chemical agent. This light-activated drug is administered or applied to the patient, followed by illumination with intense light of a specific wavelength matched to the photo-active qualities of the drug. Interaction between the drug and light causes destruction of the target tumor or lesion. Typically, a laser is used as the light source; however, other types of intense light sources may be used in certain dermatological treatments.

Several of these PDT treatments, involving the combination of a drug and laser, have been approved by regulatory agencies throughout the world. Approved applications include the treatment of lung cancer, bladder cancer, cervical cancer and esophageal cancer. Actinic keratosis, a precursor to skin cancer, has also been approved. PDT treatments under development or in the regulatory pipeline include: treatment of Barrett's esophagus (precursor to cancer), treatment of breast cancer, brain cancer, liver cancer, treatment of arterial restenosis, treatment of acne and even hair removal. As these treatments and others receive regulatory clearance over the next few years, extremely large markets will open up for PDT.

In addition, the use of PDT to treat age-related macular degeneration (AMD), a condition that leads to blindness, has recently been approved throughout the world. This ophthalmic application of PDT, which is beyond the scope of this non-ophthalmic report, is under commercial development by some of the largest eye-care companies in the world. In the first three months following FDA approval, more than 500 lasers systems were sold for use in this treatment, and Wall Street analysts estimate a $2 billion potential market for the drug used in this procedure.

The non-ophthalmic PDT markets collectively rival the ophthalmic segment, according to a report published by Medical Insight (Mission Viejo, California). This report's conservative estimates of drug sales reveal more than $700 million of revenues (during the five-year forecast period) related to drugs that are currently under commercial development. Related sales of diode lasers used in these treatments are estimated at more than 2,500 systems generating over $170 million. In addition, the disposable fiberoptic light delivery devices used in PDT procedures will produce more than $80 million in revenues for this developing industry. Thus, the total market for PDT drugs and devices during this forecast period is estimated at close to $1 billion.

Although there are six major PDT drug development companies discussed in the Medical Insight report, the supply of lasers and fibers is limited to only three manufacturers: Diomed (Andover, Massachusetts), Coherent Medical (Santa Clara, California) and Laserscope (San Jose, California). Of these three suppliers, only Diomed manufactures the diode lasers that will be used in all future PDT treatments. Medical Insight estimates that Diomed has installed about 100 diode lasers for PDT, and has pending orders for another 200 units. Diomed also exclusively supplies fiber delivery devices via patent licensing and supply arrangements with PDT companies, including Axcan Pharmaceuticals (Mont Saint-Hiliare, Quebec).

In August 2000, Axcan and Diomed signed a five-year exclusive development and supply agreement. Under the agreement, Diomed will supply Axcan with the Model 630 PDT diode lasers and optical delivery fibers for use in photodynamic therapy in conjunction with the photosensitizing drug Photofrin, which Axcan acquired from QLT (Vancouver, British Columbia) in May 2000. The FDA clearance of the Diomed laser is the first approval of a diode laser for use with Photofrin in PDT.

In addition to Axcan, Diomed reportedly has R&D and supply contracts in place with several major PDT drug companies to provide them with lasers, fibers, and technical support – from clinical studies all the way through final commercialization. These relationships cover a range of future PDT applications currently under investigation. Thus, it appears that Diomed has leveraged its position across a number of different PDT market segments as it attempts to capture the lion's share of the non-ophthalmic PDT market as the exclusive supplier of PDT light technology.

(Michael Moretti is president of Medical Insight (Mission Viejo, California), a publishing company focused on the medical laser industry. Visit for a copyof the PDT market study.)