Photodynamic therapy of cervical intraepithelial neoplasia grades II and III with Photolon.

The objective of the present study was to test in clinics a previously developed novel organ-saving approach for the treatment of CIN using PDT with the photosensitizer Photolon applied in women of a childbearing age with CIN II and III. A total number of 112 patients aged 35.2+/-1.6 with morphologically proven diagnosis of CIN II and III were enrolled into the study. All 112 patients had been observed at least during 1-year follow-up period after PDT. Among them 53 patients (44.1%) were subjected to a dynamic observation for less than 2 years; 29 patients (24.1%) were under the observation for less than 3 years; 13 patients (10.8%) - for 3-4 years and 17 women - for more than 4 years. A complete response represented by the complete regression of neoplastic lesions, which was proved by the results of morphological examinations, was revealed in 104 (92.8%) of treated women. In 3 months after treatment a complete eradication of the HPV infection was proven by PCR-analysis in 47 (53.4%) from 88 patients who have been infected with HPV of a highly oncogenic strains before PDT. PDT with Photolon is an alternative approach for the treatment of cervical intraepithelial neoplasia which can be recommended for women of childbearing age. The simplicity of the procedure as well as its' high therapeutic efficacy defines the reasonability of its' introduction into the clinical practice as a new organ-saving method for the treatment of patients with cervical intraepithelial neoplasia.

Pharmacokinetics and biodistribution of Photolon (Fotolon) in intact and tumor-bearing rats.

BACKGROUND: This paper provides the results of the non-clinical evaluation of biodistribution of the PS Photolon in inner organs and tissues of intact and tumor-bearing rats with xenograft tumors of different morphologic types. METHODS: The accumulation studies were performed in rats by means of intravital laser fluorimetry in situ and spectrophotometric determination ex vivo. RESULTS: The biodistribution pattern of Photolon does not depend on tumor carriage as well as on morphologic type of the xenograft tumor. We have also showed that Photolon easily crosses an intact blood-brain barrier and accumulates in tissues of central nervous system. The relative bioavailability of brain tissues for Photolon was estimated as 82%, T(max)-30 min, mean residual time (MRT)-1.6h. CONCLUSIONS: In general, results of the experimental study of biodistribution of Photolon in inner organs and tissues of rats, performed as in real time (by means of intravital laser fluorimetry in situ) as ex vivo (spectrophotometric assay) can be utilized while optimizing existing regimens of PDT with the purpose to increase safety and efficacy of treatment as well as for the development of new PDT protocols with Photolon applied for new indications. Parameters of pharmacokinetics and biodistribution of Photolon/Fotolon as well as its' ability to cross an intact blood-brain barrier, are optimal for the majority of modern clinical applications of PDT.