p53 Vaccine for Ovarian Cancer

Ovarian Neoplasm Clinical Trial

Official title: Vaccine Therapy With Tumor Specific p53 Peptides in Adult Patients With Low Burden Adenocarcinoma of the Ovary

Status Terminated

Clinical Trial Summary

This study will examine whether vaccination with a p53 peptide can boost an immune response to ovarian cancer and what the side effects are of the vaccine.

Many patients with ovarian cancer have an altered (mutated) gene called p53 that causes the production of abnormal proteins found in their tumor cells. The body s immune system may try, unsuccessfully, to fight these abnormal proteins. In this study, ovarian cancer patients with a p53 abnormality will be vaccinated with a p53 peptide a part of the same abnormal protein found in their tumor to try to boost their body s immune response to the cancer.

Patients will be divided into two groups. Group A will have four p53 peptide vaccinations three weeks apart, injected under the skin. The injection will include a drug called ISA-51, which increases the effect of the vaccine. This group will also receive two other drugs that boost the immune system, IL-2 and GM-CSF. Group B will have four p53 peptide vaccinations three weeks apart. The peptide will be mixed with the patient s own blood cells and infused into a vein. This group will also receive IL-2, but not GM-CSF.

All study candidates will be tested to see if their cancer has a p53 abnormality and if their immune system mounted a defense against it. These tests may include a tumor biopsy (removal of a small part of the tumor for microscopic examination); lymphapheresis (a procedure to take blood, remove white blood cells called lymphocytes, and return the red cells); and an immune response test similar to a skin test for tuberculosis. During the study, patients will have additional skin tests and blood tests.

Clinical Trial Description

P53 is the most commonly mutated gene in human cancers; it has been found to be mutated in almost 50% of ovarian cancers. Genetic mutation of p53 results in stabilization and increase in the level of the protein. In some cases, overexpression of p53 protein could also occur in tumors without detectable mutation in the open reading frame. Therefore, p53 could function as an antigen through two different mechanisms, as a mutant "foreign" protein and as a selfoverexpressed protein. The p53:264 - 272 wild type peptide has been shown to have high affinity for HLA-A2. It has also been shown to be naturally processed and endogenously

presented by HLA-A2 in different types of tumor cell lines for CTL recognition. These CTL

were able to lyse tumor cells overexpressing wild type or mutant p53 protein and failed to lyse

normal cells expressing normal levels of wild type p53.

In this protocol we will be vaccinating HLA-A2+ ovarian cancer patients who carry tumors which overexpress p53 with the wild type p53 peptide (264-272). This will be given either subcutaneously admixed with ISA-51 and GM-CSF adjuvants, or intravenously pulsed on dendritic cells along with low dose subcutaneous IL-2. In addition, those patients who express mutant p53 may also be vaccinated with a mutant p53 peptide, which corresponds to the mutation they harbor in their tumor, should the patients progress on the p53 (264-272) peptide. ;

Related Conditions & MeSH terms

• Ovarian Neoplasm
• Ovarian Neoplasms

• NCT number: NCT00001827
• Study type: Interventional
• Source: National Institutes of Health Clinical Center (CC)
• Status: Terminated
• Phase: Phase 2
• Start date: July 26, 1999
• Completion date: January 25, 2013