Cervical cancer vaccine developed

Scientists led by a researcher of Indian origin have developed the world’s first therapeutic vaccine for cervical cancer that kills 85,000 Indian women every year.

Tested successfully on 18 women displaying early symptoms of cervical cancer, the vaccine has now entered into clinical trial on 148 patients in 34 centres worldwide, the results of which are expected by March 2014.

Caused by human papillomavirus (HPV), cervical cancer is one of the two most common cancers in women accounting for 493,000 new cases and 274,000 deaths every year. For large parts of the world the HPV disease burden is quite significant – approximately 10 per cent of women worldwide are HPV infected.

The trend is similar in India too where 1.3 lakh new cases are reported every year and 80-85,000 die painful deaths. The World Health Organisation attributed the cause entirely to HPV whose two strains – type 16 and 18 – triggers the maximum damage.

“This is a DNA vaccine targeting HPV 16 and 18 subtypes. It is a 3 dose regimen,” Niranjan Sardesai, chief operating officer at Inovio Pharmaceticals, a Pennsylvania-based firm that developed the vaccine told Deccan Herald.

The findings have been published in Science Translational Medicine on Friday. Previous attempts to make a therapeutic HPV vaccine met with little success.  Though there are existing preventive vaccines for HPV, they are not effective once a person is infected with the virus.

Furthermore, not all eligible girls and women are receiving these vaccines making the need for a therapeutic vaccine that much critical. It has been estimated that 50 lakh cervical cancer deaths would occur in the next 20 years due to existing infections.

Unlike conventional vaccines, the new vaccine, VGX-3100, is a therapeutic one designed to combat existing cervical cancer and control pre-cancerous lesions. Initial results suggest that the vaccine is safe and works in a manner similar to gene therapy. “It is an excellent attempt as there is no therapeutic vaccine against HPV at the moment.

However, the researchers have to prove its efficacy on full fledged cancer before the vaccine comes to the market,” commented Bhudev Das, former director of Institute of Cytology and Preventive Oncology under the Indian Council of Medical Research, who also researches on HPV vaccines.

The mode of administration, however, could be a problem. Currently, the DNA vaccine is given as an intra-muscular injection (like many of the other common vaccines) followed by the application of three short electric pulses (on the order of 50 milli-seconds each) over a period of less than 4 seconds. The pulses help deliver the vaccine directly into the cells rather than in body's own circulation system.