The US Food and Drug Administration (FDA) has placed a temporary hold on Inovio Pharmaceuticals’ mid-to-late stage coronavirus vaccine trial.
The company announced on Monday that the FDA had ‘additional questions’ about its planned phase 2/3 trial of its vaccine candidate INO-4800, as well as the delivery device to be used in the trial.
Inovio added that it is actively working to address the FDA’s questions and has plans to respond in October, at which point the agency will have up to 30 days to notify Inovio of its decision.
Importantly, the clinical hold is not due to the occurrence of any adverse events related to the vaccine, Inovio said in the statement. This means that the company’s ongoing phase 1 study of INO-4800 can continue and is not affected by the FDA hold.
Currently, Inovio has 15 DNA medicine clinical programmes in development focused on HPV-associated diseases, cancer and infectious diseases – including coronaviruses associated with MERS and COVID-19 diseases.
Inovio’s COVID-19 vaccine candidate is composed of optimised DNA plasmids, which are delivered directly into cells intramuscularly or intradermally using its proprietary hand-held CELLECTRA device.
The CELLECTRA device provides a brief electrical pulse to reversibly open small pores in the local skin area cells, which Inovio says increases product delivery by ‘a hundred-fold’.
When the DNA plasmids are delivered, they instruct cells to produce the targeted antigen, which is then processed naturally and triggers specific T-cell and antibody-mediated immune responses.
Earlier this month, AstraZeneca’s global clinical development of its Oxford University-partnered COVID-19 vaccine candidate was placed on hold after a participant in the British trial fell ill with unexplained neurological symptoms.
Although trials have since restarted in the UK and other locations, the US-based study still remains on hold as regulators determine whether the side-effect was associated with the vaccine or not.
“Regulators in each individual country determine when trials can start and they do this in their own timeframe. Companies provide the information to the regulators to enable them to make this determination,” AstraZeneca said in a statement.
“On the current US status specifically, we are continuing to work with the FDA to facilitate a review of the information and the agency will decide when the US trial can resume,” the statement added.