Photodynamic therapy with 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a is safe, promising
THURSDAY, Sept. 8 (HealthDay News) -- Photodynamic therapy (PDT) with 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH) is safe with promising efficacy in precancerous lesions associated with Barrett's esophagus, according to a study published in the September issue of Lasers in Surgery and Medicine.
Hector R. Nava, M.D., from the Roswell Park Cancer Institute in Buffalo, N.Y., and colleagues investigated the optimal drug and light doses, and toxicity of endoscopic PDT with HPPH (HPPH-PDT) in precancerous lesions in Barrett's esophagus, and the efficacy of one-time treatment with HPPH-PDT. A total of 36 patients with biopsy-proven high grade dysplasia or early intramucosal adenocarcinomas of the esophagus participated in two non-randomized (18 patients each) dose escalation studies. In the drug dose ranging study, HPPH doses of 3 to 6 mg/m² were followed by one endoscopic fixed light dose of 150 J/cm, 48 hours after HPPH infusion. In the light dose ranging study, three light doses (150, 175, or 200 J/cm) were delivered 24 hours after HPPH administration at two doses (3 and 4 mg/m²).
The investigators found that most patients had mild to moderate chest pain requiring symptomatic treatment, and 16.6 percent of the patients experienced grade 3 or 4 adverse events. Esophageal strictures were treated by dilatation in three cases. There was no clear pattern of dose dependent toxicities. For the drug dose ranging study 3 and 4 mg/m² of HPPH were the most effective. The light dose ranging study had a one-year complete response rate of 72 percent (disappearance of high grade dysplasia and early carcinoma). A one-year complete response rate was seen in all patients treated with 3 mg/m² HPPH with 175 J/cm and 4 mg/m² HPPH with 150 J/cm.
"HPPH-PDT for precancerous lesions in Barrett's esophagus appears to be safe and showing promising efficacy," the authors write.
Two of the study authors disclosed financial relationships with the pharmaceutical industry.
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