Photodynamic therapy (PDT) was the selective destruction of abnormal cells through light activation of a photosensitiser in the presence of oxygen. These cells accumulated more photosensitiser than normal cells. The photosensitiser generated reactive oxygen species upon illumination. For skin diseases, there had been an increasing interest in using precursors of the endogenous photosensitiser protoporphyrin IX (PpIX). The most commonly used precursors have been 5-aminolevulinic acid (ALA) and its derivatives. The present test drug, Metvix, contained the methyl ester of ALA, which penetrated the lesions well and shows high lesion selectivity. In vitro studies of animal and human tissues had shown significant intracellular formation of photoactive porphyrins after addition of Metvix. The increased photoactive porphyrins levels induced cytotoxic effects in tumour cells after photoactivation. The primary objective was to compare PDT with Metvix cream to PDT with placebo cream in terms of participants complete response rates based on histologically verified disappearance of the lesions at 6 months after last treatment cycle. Secondary objectives was to compare the two treatments in terms of histological and clinical mean participant response weighted by the number of lesions within a participant, lesion response rates across participants, clinical complete participant response, cosmetic outcome and adverse events.
A participants were randomised to PDT with Metvix cream or PDT with placebo cream. All eligible basal cell carcinoma (BCC) lesions within a participant received same treatment. All participants received two consecutive treatments one week apart. At the 3-months follow-up visit, lesions with no clinical response or progression were surgically excised. Lesions with partial response 50 percent (%) or greater reduction on lesion area) were re-treated; if they do not show complete response three months later, they were surgically excised. Lesions with complete response were surgically excised 6 months after the first or second PDT cycle. All excised tissue specimens were histologically examined.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
65
Clinical Research Specialists Inc
Santa Monica, California, United States
Department of Dermatology, University of Minnesota Hospital and Clinic
Minneapolis, Minnesota, United States
Department of Dermatology, Mayo Medical School, Mayo Clinic
Rochester, Minnesota, United States
Academic Dermatology Associates
Albuquerque, New Mexico, United States
Department of Dermatology, Roswell Park Cancer Institue
Buffalo, New York, United States
Northwest Cutaneous Research Specialists
Portland, Oregon, United States
DermResearch, Inc.
Austin, Texas, United States
Texas Dermatology Research Institute
Dallas, Texas, United States
Virginia Clinical Research, Inc.
Norfolk, Virginia, United States
Number of Participants With Histologically Confirmed Complete Response
The histological complete response was defined as 100 percent (%) of the lesions within the participant having negative findings in the histological examination. Histological examination included evaluation of all the microscopical slides from the excised tissue for presence of malignant basal cells. Complete response was defined as complete disappearence of lesion. Number of participants with histologically confirmed complete response were reported.
Time frame: up to 9 months
Percentage of Lesions With Histologically Confirmed Complete Lesion Response
Histological response weight means no signs of malignant basal cells in all microscopical slides containing excised tissue. The histologically confirmed complete lesion response were reported.
Time frame: up to 9 months
Percentage of Lesions With Clinically Confirmed Complete Lesion Response
Clinically confirmed complete lesion response means no signs of malignant basal cells in all microscopical slides containing excised tissue. The clinically confirmed complete lesion response were reported.
Time frame: up to 9 months
Histological Verified Lesions With Complete Response
Histological confirmed complete lesion response means no signs of malignant basal cells in all microscopical slides containing excised tissue. Number of histologically confirmed lesions with complete response were reported.
Time frame: up to 9 months
Clinically Verified Lesions With Complete Response
Clinically confirmed complete lesion response means no signs of malignant basal cells in all microscopical slides containing excised tissue. Number of clinically confirmed lesions with complete response were reported.
Time frame: up to 9 months
Number of Participants With Clinically Evaluated Complete Response
The on-site investigator evaluated the lesion response by comparing to the lesion size before and after treatment. Complete response here means complete disappearance of a lesion. Number of participants for whom one or more lesions had a complete response were reported.
Time frame: up to 9 months
Number of Participants With Cosmetic Outcome Assessed by Investigator and Participants
Cosmetic outcomes were assessed with regards to occurrence of the following signs or symptoms; scarring, atrophy, induration, redness or change in pigmentation. Cosmetic outcome were graded as excellent, good, fair or poor where: excellent: no scarring, atrophy or induration, no or slight occurrence of redness or change in pigmentation compared to adjacent skin; good: no scarring, atrophy or induration but moderate redness or change in pigmentation compared to adjacent skin; fair: slight to moderate occurrence of scarring, atrophy or induration and Poor: extensive occurrence of scarring, atrophy or induration. The investigator and participants assessed the cosmetic outcome for each lesion has responded completely. Participants were asked to evaluate evaluate the cosmetic outcome according to the same categories: excellent, good, fair cosmetic outcome. Number of participants with summarized cosmetic outcomes for all symptoms as assessed by Investigator and participants were reported.
Time frame: up to 9 months
Number of Participants With Adverse Events and Serious Adverse Events (AEs)
Adverse event (AE) was defined as any untoward medical occurrence in a participant, which does not necessarily have causal relationship with treatment. A serious AE was defined as an AE that resulted in any of the following outcomes: death; life threatening; persistent/significant disability/incapacity; initial or prolonged in participant hospitalization; congenital anomaly/birth defect or was otherwise considered medically important. TEAEs: events between first dose of study drug that were absent before treatment/that worsened relative to pre-treatment state. TEAEs included both serious TEAEs and non-serious TEAEs. Number of participants with AEs and serious AEs were reported.
Time frame: up to 6 months
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