Cidofovir, an antiviral drug that is well established as a treatment for infection of the retina in people with AIDS, has been shown to be effective in combination with chemoradiation in a phase I study of women with human papillomavirus (HPV)-related cervical cancer. The study results were presented at the recent EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics in Barcelona.1
Fifteen women were enrolled in the study and received injections of cidofovir at doses ranging from 1 to 6.5 mg per kilogram of body weight weekly for 2 weeks, and then every 2 weeks from the start of chemoradiation (45 Gy radiotherapy delivered to the pelvis and weekly intravenous carboplatin until the start of brachytherapy in the uterus and vagina). The women received a total of six injections of cidofovir, and the median duration of therapy was 10 weeks. The combination of cidofovir and chemoradiation resulted in tumor shrinkage in all patients and did not increase toxicity or the tumor’s resistance to radiation.
“The major finding from the trial is that cidofovir did not increase the toxicity or worsen the tolerability of chemoradiation,” said Eric Deutsch, MD, PhD, Professor of Radiation Oncology at the Institut Gustave Roussy, in Villejuif, France, and a coauthor of the study, in a press statement. “We also found that the combination resulted in tumor shrinkage in all the patients who could be evaluated in the trial, with a complete response, in which the tumors disappeared for a time, in 80% of these patients.”
A Safe Approach
Although one of the major side effects from cidofovir can be kidney damage, none was seen in this trial, suggesting the dosage was safe.
“The results from this phase I trial show that the combination of cidofovir with chemoradiation is a new, targeted anticancer approach, which enables us to target cancer cells specifically with a limited impact on healthy tissues, thereby avoiding unacceptable adverse side effects,” said Dr. Deutsch.
The researchers hope to launch a phase II/III trial soon to investigate how the combination therapy impacts overall survival. ■
Disclosure: The study authors reported no potential conflicts of interest.
1. Deutsch E, et al: Phase I trial evaluating the antiviral agent cidofovir in combination with chemoradiation in cervical cancer patients: A novel approach to treat HPV related malignancies? EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics. Abstract 219. Presented November 20, 2014.