ClearPap. Device to treat pre-cancer lesions associated with HPV

Jesús Manuel Muñoz

Fundación para la Investigación Biomédica del Hospital Universitario La Paz, Madrid, Spain

Human papillomavirus (HPV) is a high prevalence infection with rates close to 80 % in sexually active individuals between 15 and 55 years of age. Some HPV serotypes cause cellular alterations that lead to the appearance of lesions in the mucous membranes of the vagina, cervix and anus, which can evolve into cancerous lesions.

ClearPap is a device to apply photodynamic therapy (PDT) and an adjuvant antiviral for the treatment of HPV preneoplastic lesions, with added advantages of light diffusion and increased immune response with mitigation of side effects.

The natural history of precursor lesion of anal cancer, high-grade squamous intraepithelial lesion (HSIL), indicates that treatment of anal HSIL could lead to a considerable decrease in the incidence of invasive anal cancer.

Currently, the preferred treatment is ablation of localised lesions. This method has a success rate of less than 50 % and high rates of early relapse leading to virus reinfection.

Any intervention that increases effectiveness and adherence to treatment is a great advance for these patients. Photodynamic therapy offers a simple, noninvasive method for treatment of anal intraepithelial neoplasia and other HPV-related lesions such as condylomas and cervical lesions.

ClearPap combines light emission with added advantages of light diffusion and an antiviral elution in the same device. Both treatments have been used separately in cases of HSIL and other HPV related diseases, and both provoke direct damage to HPV transfected cells and promote immune response. Combined with other therapies they have brought about a reduction in HPV load and recurrence. PDT has traditionally been limited due to the difficulty of 3D anatomy. However, this technology has demonstrated homogeneous diffused light emission in the therapeutic range of dose.