Cervical cancer, which is caused by HPV infection, is characterized by the progressive formation of dysplastic lesions, known as cervical intraepithelial neoplasia (CIN). Although vaccinations for the prevention of cervical cancer have been developed, the current vaccine has a high cost, targets only two-thirds of HPV strains, and is effective only when administered prior to HPV infection. In the U.S. alone, 1.2 million cases of low-grade CIN and 0.2-0.3 million cases of high-grade CIN are diagnosed annually;yet, no FDA- approved drug therapies are available for its treatment. For women diagnosed with low-grade CIN, the standard approach is "watchful waiting;" women with high-grade CIN are treated with the loop electrosurgical excision procedure (LEEP). Despite this treatment, a significant recurrence rate of high-grade CIN occurs. What is needed is a medical treatment option for resolving these lesions during the early stages of CIN. Project Goal and Technological Innovation. This project will develop continuous-release implants, containing a natural compound - specifically withaferin A - for the prophylactic treatment of high-risk patients with cervical cancer and other cervical pathologies. The implant to be used at the target site, promises a significant advance in cancer prevention and treatment. Natural compounds administered orally are often accompanied by limited bioavailability while chemotherapeutics administered intravenously result in undesirable large spikes in the blood. The development of polymeric implants to provide continuous delivery of therapeutic agents directly to the target site would substantially lower its effective dose, and minimize toxicity concerns generally associated with high oral and i. v. doses. The main objective of this project is to optimize polymeric implants ("cervical inserts") for continuous ("24/7") release of withaferin A at the target site (ie., the cervix) using a large animal model, the goat. The studies described represent the necessary pre-clinical efforts to examine potential toxicity and rate of release of withaferin A from the cervical implants. In addition, the concept of continuous local delivery of cancer chemopreventives is a novel and innovative concept that has the potential to revolutionize the clinical management of high-risk individuals. The new, patient-friendly device would be an economic treatment. Furthermore, prophylactic treatment with natural compounds delivered locally may obviate the need for LEEP. The implant delivery device is currently under a pending patent, with one of the PIs (Dr. Gupta) as the inventor. Hypothesis and Specific Aims. We hypothesize that withaferin A, a triterpenoid, which has no known toxicity and has significant antiproliferative and anti-viral activities against human cervical cancer cells in vitro and in viv, when embedded in polymeric implants, will be released continuously at the target site for extended periods, and that no tissue or systemic toxicity associated with either the drug or the polymeric materials will be produced.
The specific aims are to (1) optimize the formulation of polymeric cervical inserts and determine rate of drug release in vitro;and (2) using a large animal (goat) model, determine, the rate of drug release from cervical inserts, any systemic and tissue toxicity, and the levels of the drug in plasma, and local, surrounding and distal tissues. Future efforts will involve examining still longer-term drug release and potential longer-term or delayed toxicity, obtaining FDA approval, and conducting a clinical trial with cervical dysplasia patients.
The overall goal of this research project is to develop polymeric cervical implants (cervical inserts) that can provide continuous release of compounds with therapeutic activity against cervical pre-cancer and cancer directly to the target site. When placed in the cervix these implants can deliver drugs continuously (24/7) for months, potentially obviate the need for electrosurgical excision of pre-cancerous lesions, and ultimately prevent the development of cervical cancer. This prophylactic treatment will benefit hundreds of thousands of women in the United States alone, who otherwise would require a surgical procedure. Worldwide, the benefits of this approach will be far greater, because cervical cancer is the second most common cancer among women after breast cancer. In this pilot project, we will optimize cervical inserts and assess any potential toxicity associated with both the implant materials and with a naturally-occurring compound (withaferin A) with potent anticancer activity against cervical pre-cancer/cancer, using a large animal (goat) model.