Inovio's SynCon® vaccines are designed to provide two capabilities not achievable with conventional vaccines: stimulation of T-cell immune responses to provide therapeutic capabilities, and universal cross-strain protection and treatment against known as well as newly emergent unmatched strains of pathogens. The company has clinical programs for cervical dysplasia, leukemia, the hep C virus, the flu and HIV.
For many years, vaccines were associated with the prevention of infectious diseases, but "gradually, research began to harness the activity of the immune system to prevent disease as well as treat it, starting in the field of oncology," writes FierceVaccines' Suzanne Elvidge.
One of the first therapeutic vaccines on the market - Dendreon's Provenge - gained FDA approval in 2010 for the treatment of advanced hormone-refractory prostate cancer.
After therapeutic cancer vaccines began to develop, the idea spread to virally-targeted vaccines, such as those against HIV, and HPV, which is the leading cause of cervical cancer.
The first of Inovio's candidates on the list at #4 is VGX-3100 - targeted for high risk types of HPV, or the human papillomavirus - which is behind 90 per cent or more of cervical cancer cases.
"Treating cervical cancer in its earliest stages, when doctors spot precancerous changes in the cervix, is the next target for vaccines, and Inovio Pharmaceuticals has created a DNA vaccine, VGX-3100, for this indication, which is currently in a global Phase II clinical trial," the FierceVaccine article notes.
The SynCon synthetic vaccines include a fragment of DNA that codes for an antigen, and Inovio uses electroporation--a small electric charge that loosens up the cell membrane -- to let the vaccine through.
VGX-3100 is designed to raise immune responses against the E6 and E7 oncogenes associated with HPV types 16 and 18, targeting four antigens. The idea is to stimulate a T-cell immune response strong enough to cause the rejection of the HPV-infected cells, which can turn into pre-cancerous or cancerous cells.
Recently, the company saw its stock surge after it showed for the first time that its therapeutic synthetic vaccine VGX-3100 can kill cells changed by HPV into precancerous cervical dysplasias.
The vaccine maker is now assessing the ability of its DNA-based vaccine to treat cervical dysplasias caused by HPV infection in a global phase II trial. Specifically, the study will look to determine the vaccine's ability to reverse disease progression to cervical cancer.
Results from the phase I trial appeared in a peer-reviewed journal, Science-Translational Medicine. The proof-of-concept study involed 18 women who had previously been treated for precancerous changes in the cervix, and were given Inovio's vaccine. All 18 patients showed an immune response to the vaccine, and in 78 per cent of patients, the vaccine triggered a T-cell response.
Invovio's second promising candidate on the list is PENNVAX-B, a SynCon synthetic DNA vaccine that has potential to both treat and prevent infection with HIV from clade B, the subtype of virus mostly seen in North America and Western Europe.
The vaccine is also administered with the company's CELLECTRA electroporation device, which uses a small electric pulse.
The FierceVaccines article states: "Targeting HIV infection is a huge market--according to UNAIDS, nearly 30 million people have died from HIV-related causes and roughly 34 million are living with HIV.
"While antiretroviral therapy has made a massive difference in the developed world, and the cost of the drugs has dropped, there is still a cost implication for the developing world, and market and patient access can be difficult.
"Therapeutic vaccines could be a more patient-friendly approach, with improved convenience and potentially fewer side effects."
In a phase I trial, 12 people with HIV were given four doses of the vaccine over 16 weeks, with interim results showing that the vaccine triggered a T-cell immune response to at least one antigen in 75 per cent of the people in the study.
Inovio also has a preventative and therapeutic HIV vaccine that it is developing, dubbed PENNVAX-G, which targets clades, A, C, and D that are found in developing regions of Africa and Asia.
Other notable candidates on the FierceVaccine list included CAD106, a vaccine co-developed by Novartis (NYSE:NVS) and Cytos that has shown "early hints" of immune responses in a clinical trial in people with Alzheimer' s disease.
The FierceVaccines special report spotlights 10 promising therapeutic vaccines on their way through clinical development. To view the article, please click here: http://www.fiercevaccines.com/special-reports/10-promising-therapeutic-vaccines-2012