The pharmacokinetics and safety of porfimer after repeated administration 30-45 days apart to patients undergoing photodynamic therapy: Pharmacokinetics and safety of porfimer after repeated doses

P>Background Porfimer is an intravenous (i.v.) injectable photosensitizing agent used in the photodynamic treatment of tumours and of high-grade dysplasia in Barrett's oesophagus. Aim To assess the pharmacokinetics as well as the safety profiles of porfimer after a first and a second dose administered 30-45 days apart in patients undergoing photodynamic therapy. Methods Nineteen patients (16 with cholangiocarcinoma) were enrolled. Porfimer sodium was administered by i.v. injection over 3-5 min. Blood samples were collected prior to starting i.v. drug injection and postdose at different time points after the first and second administrations. Results Porfimer exposure values after the second administration were statistically higher than those observed after the first administration, suggesting a slight accumulation of porfimer following repeated administration. The apparent mean elimination half-life of porfimer increased from 410 h after the first administration to 725 h after the second administration. The safety profiles of porfimer after a first and a second administration were similar and did not raise additional concern. Eight patients experienced nine serious adverse events. Only photosensitivity was deemed study-drug related. Conclusion Porfimer appears to display a safe and tolerable profile when used in patients requiring a second photodynamic therapy within 45 days.