Vaccine Info

GLS-5300 MERS-CoV Vaccine

GLS-5300 Vaccine Description

GLS-5300 (INO-4700) is a DNA plasmid vaccine that expresses the MERS CoV spike (S) glycoprotein.

The GLS-5300 MERS-CoV product is a DNA vaccine candidate, which allows for rapid design and production in response to emerging infectious diseases. Underscoring the potential for rapid deployment of DNA vaccines, GLS-5300 was advanced into the clinic within nine months of preclinical vaccine candidate selection.

GLS-5300 (INO-4700) was co-developed by GeneOne Life Science Inc. and Inovio Pharmaceuticals.

In 2020, Inovio expects to advance INO-4700, its candidate vaccine against MERS (Middle East Respiratory Syndrome), into a Phase 2 field study in the Middle East and Africa where outbreaks have been observed, with full funding from CEPI. On January 6, 2020, the company says this is the most advanced vaccine candidate for MERS.

GLS-5300 Vaccine Indication

Human coronaviruses such as MERS were first identified in the mid-1960s. The best-known Conoaviruses are Middle East Respiratory Syndrome (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS-CoV). Human coronaviruses were first identified in the mid-1960s. The best-known Conoaviruses are Middle East Respiratory Syndrome (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS-CoV) and the 2019 Novel Coronavirus (2019-nCoV).

GLS-5300 (INO-4700) is indicated to prevent Middle East Respiratory Syndrome Coronavirus (MERS). MERS is a deadly viral respiratory disease caused by MERS-coronavirus (MERS-CoV) infection. To date, there is no specific treatment proven effective against this viral disease. In addition, no vaccine has been licensed to prevent MERS-CoV infection thus far.

Overall, vaccine candidates against MERS-CoV are mainly based upon the viral spike (S) protein, due to its vital role in the viral infectivity, although several studies focused on other viral proteins such as the nucleocapsid (N) protein, envelope (E) protein, and non-structural protein 16 (NSP16) have also been reported. In general, the potential vaccine candidates can be classified into six types: viral vector-based vaccine, DNA vaccine, subunit vaccine, nanoparticle-based vaccine, inactivated-whole virus vaccine, and live-attenuated vaccines.

The majority of the identified MERS-CoV cases are nosocomially acquired via direct close contact with infected patients (Chowell et al., 2015; Cauchemez et al., 2016), whereas cases of zoonotic transmission from dromedary camels to humans were reported primarily in Saudi Arabia, where human-camel interaction is more frequent.

On April 13, 2020, a study reported a single dose of ChAdOx1 MERS provides broad protective immunity against a variety of MERS-CoV strains.

GLS-5300 Vaccine Dosage

GLS-5300 is administered intramuscularly using the CELLECTRA® delivery device.

GLS-5300 Vaccine News

September 2019 - Immune responses were dose-independent, detected in more than 85% of participants after two vaccinations, and durable through 1 year of follow-up. The data support further development of the GLS-5300 vaccine, including additional studies to test the efficacy of GLS-5300 in a region endemic for MERS coronavirus.

July 24, 2019 - Initial findings from the trial were published today in The Lancet Infectious Diseases. The study, conducted at the Walter Reed Army Institute of Research Clinical Trials Center, evaluated a candidate DNA vaccine (GLS-5300) co-developed by GeneOne Life Science Inc. and Inovio Pharmaceuticals. Though other vaccine candidates have previously been tested for use in camels, which are the suspected source of the virus that causes MERS, this is the first vaccine candidate to be tested in humans.

The GLS-5300 MERS CoV vaccine was well tolerated with no major side effects reported by the volunteers. More than 85 percent of volunteers exhibited a detectable immune response to MERS CoV after just two vaccinations. This immune response persisted throughout the study and was similar in magnitude to the response seen in survivors of natural MERS CoV infection.

Vaccine Clinical Trials

Clinical Trial NCT03721718Evaluate the Safety, Tolerability, and Immunogenicity Study of GLS-5300 in Healthy Volunteers - last updated May 27, 2020.

  • This Phase I/IIa study will evaluate the safety, tolerability, and immunogenicity of GLS-5300 administered intradermally (ID) followed by electroporation at 0.3 and 0.6 mg/dose assessing 2 and 3-dose regimens. 
  • Subjects vaccinated with INO-4700 displayed robust levels of MERS antigen-specific antibody and T cell responses at week 14 (two weeks post-third dose). These vaccine-generated immune responses to INO-4700 were durable as they were maintained through 60 weeks following dosing.

Clinical Trial NCT02670187: Phase I, Open-Label Dose-Ranging Safety Study of GLS-5300 in Healthy Volunteers

  • The Middle East Respiratory Syndrome Coronavirus (MERS CoV), a virus related to Severe Acute respiratory syndrome coronavirus (SARS CoV), was first recognized as a cause of severe pulmonary infection in 2012.
  • Infection with MERS CoV has been diagnosed in more than 1600 individuals with a mortality rate between 35% and 40%.
  • GLS-5300 is a DNA plasmid vaccine that expresses the MERS CoV spike (S) glycoprotein.
  • This study will evaluate the safety of GLS-5300 at one of three dose levels following a three-injection vaccination regimen followed by electroporation.
  • The study will also assess immune responses over a 1 year period with respect to the generation of antibody and cellular responses.