| abstract |
A photosensitizer suitable for use in administering photodynamic therapy (PDT), conjugated with antibodies that are targeted to antigens on abnormal tissue and polyethylene glycol (PEG) or other polymer that extends the residence time of the conjugate within a patient's body. The resulting pegylated targeted conjugate is administered to a patient, and after the antibodies have had sufficient time to bind with the antigens, light from an external or internal source having a waveband corresponding to an absorption waveband of the photosensitizer is administered. Use of an external light source that emits relatively long wavelength light enables the light to pass through any intervening dermal layer and normal tissue between the external light source and the treatment site. Since the photosensitizer in the conjugate is bound to the abnormal tissue, the light therapy has minimal effect on the intervening normal tissue. Furthermore, the efficacy of the PDT is enhanced due to the increased concentration of the photosensitizer of the conjugate linked to the abnormal tissue. |