Inovio announced the hold on Monday, explaining the Food and Drug Administration (FDA) had asked for data to support the shelf life of the disposable parts of the Cellectra 5pSp device used to deliver VGX-3100.
The firm said it “is working diligently with the FDA to address its concerns and anticipates that the requested data will be available before the end of this year.”
It also predicted the study - which has not begun - will start next year, assuming the data it provides satisfies the FDA’s request.
VGX-3100 is a DNA vaccine designed to prevent pre-cancers and cancers caused by human papillomaviruses (HPV). The vaccine consists of plasmids targeting the E6 and E7 proteins of HPV types 16 and 18.
The vaccine is administered by intramuscular injection. The Cellectra is a device applied to the injection site to encourage cells to take up the plasmids through a process called electroporation.
Electroporation involves applying controlled, millisecond electrical pulses to increase the permeability cell membrane.
Using the device Inovio claims to have increased levels of gene expression of ‘naked’ DNA vaccines by 100-fold compared to conventional injection.
Swiss drug manufacturer Roche licensed rights to the Cellectra technology in 2013.