GLS-5300 SynCon® immunotherapy targeting Middle East Respiratory Syndrome
MilestonePhase I trial data 2016
Inovio is developing GLS-5300, a DNA immunotherapy designed to provide broad protective antibody and therapeutic T cell responses against multiple strains of MERS virus.
Inovio's MERS vaccine advanced into a phase I clinical trial in healthy volunteers in the first quarter of 2016. Inovio and GeneOne Life Science Inc. are co-developing GLS-5300 in collaboration with the Walter Reed Army Institute of Research, where the trial is being conducted.
Middle East Respiratory Syndrome is caused by a coronavirus that is related to the severe acute respiratory syndrome (SARS). While SARS infected more than 8,000 people, the disease was short-lived between 2002 and 2004 and had a mortality rate of about 10%. Since 2012, MERS has infected over 1,600 people, with almost 600 deaths, a mortality rate of about 40%, and is still ongoing. Highlighting the global concern for MERS, in the summer of 2015 an infected person returning from Saudi Arabia to South Korea was responsible for a country-wide outbreak involving 186 persons with a 20% mortality rate.
GLS-5300 SynCon® MERS immunotherapy
GLS-5300 is a DNA plasmid immunotherapy encoded for the MERS CoV spike (S) glycoprotein. The phase I study will evaluate the safety of GLS-5300 at one of three dose levels following a three-injection vaccination regimen delivered using electroporation. The study will also assess the generation of antibody and cellular immune responses over a one year period.
GLS-5300 SynCon® MERS immunotherapy
Inovio evaluated its synthetic DNA-based MERS immunotherapy in preclinical studies in mice, camels, and monkeys. In all three species, the immunotherapy induced robust immune responses capable of preventing the virus from infecting cells. The data from camels is an important finding because camels represent not only a host reservoir of the disease but act as a mode of transmission to humans. In monkeys, all vaccinated animals in the study were protected from symptoms of MERS disease when challenged with a live MERS virus. Results from this trial appear in the peer-reviewed journal Science Translational Medicine in an article entitled, "A synthetic consensus anti-spike protein DNA vaccine induces protective immunity against Middle East Respiratory Syndrome Coronavirus in non-human primates."
First identified in humans in 2012, Middle East Respiratory Syndrome is a zoonotic virus that is transmitted from animals to humans. The virus was believed to have originated in bats before being transmitted to camels in the distant past. Scientists now believe camels to be the major reservoir host for MERS and the animal source of infection in humans. In fact, according to the World Health Organization (WHO), strains of MERS that are identical to human strains have been isolated from camels in several countries, including Egypt, Oman, Qatar, and Saudi Arabia. Once a human is infected with MERS, the virus can pass from human to human upon close contact with an infected individual.
The majority of cases (>85%) of MERS have occurred in Saudi Arabia, however, an influx of cases have been reported outside of the Middle East, including South Korea and the U.S. The majority of infected patients have severe acute respiratory illness with symptoms including fever, cough, and shortness of breath, and roughly three to four out of ten patients die from the disease. There are currently no preventive vaccines or effective treatments for MERS. Treatment involves supportive care and is dependent upon a patient’s clinical condition.