VGX-3100 is a therapeutic DNA vaccine being investigated for the treatment of pre-cancers and cancers such as cervical cancer, caused by the human papillomavirus (HPV) subtypes 16 and 18 (HPV-16 and HPV-18). It is being developed by Inovio Pharmaceuticals.

How VGX-3100 works

VGX-3100 utilizes the patient’s own immune system to eliminate infections caused by HPV-16 and HPV-18 and to destroy pre-cancerous cells, or “lesions.”

The VGX-3100 vaccine is administered through an injection given directly into the muscle (called an intramuscular injection) combined with a technique called electroporation. Electroporation consists of applying short electrical pulses at the site of the injection to increase its uptake by the body and stimulate the immune response, maximizing the vaccine’s effect.

VGX-3100 in clinical trials

Two clinical studies have tested the therapeutic effects of VGX-3100.

In the initial Phase 1 study (NCT00685412) conducted in 18 women, each patient received three rounds of vaccination. The results showed that the vaccine was well-tolerated, with the only adverse effects reported consisting of reactions at the injection site, fever, pain, and soreness or irritation of the skin (tenderness). Fourteen of the 18 women (78%) showed production of specific immune cells (called CD8+ T-cells) against the virus.

These initial results showed the potential of VGX-3100 to induce a robust immune response and contribute to the eradication of HPV-infected cells and to the regression of lesions caused by the virus.

The results encouraged the development of a follow-up Phase 2b study (NCT01304524) in 167 women to further investigate the therapeutic effectiveness of VGX-3100. In this study, conducted in seven different countries including the U.S., 49.5% of vaccinated women demonstrated regression of the virus-caused lesions compared with 30.6% of women who received a placebo vaccine, confirming the favorable results of the Phase 1 study. Side effects were reactions at the site of injection, fever, chills, abdominal discomfort, and vomiting.

Next steps for VGX-3100

In June 2017, Inovio started its Phase 3 clinical program to evaluate the effectiveness and safety of VGX-3100 vaccine in treating cervical cancer caused by HPV. The program consists of two clinical trials named REVEAL. The first study, (REVEAL 1, NCT03185013), is currently recruiting participants and will be followed by a confirmatory study (REVEAL 2). Each study plans to enroll 198 women in more than 100 study centers globally.

VGX-3100 has the potential to be the first treatment for HPV infection of the cervix, offering women the possibility of preventing cervical cancer without undergoing an invasive surgical procedure that may compromise their reproductive health.


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