Vaccine candidate for RSV well tolerated in patients in first part of Phase 1 clinical trial

15 December 2015
​Immunovaccine Inc., a clinical stage vaccine and immunotherapy company, announced its Respiratory Syncytial Virus vaccine candidate (“DPX-RSV”) was well tolerated in the Phase 1 study’s first 20 participants, of which 8 subjects received the DPX-RSV vaccine. The RSV vaccine candidate has been developed by Bert Schepens, Walter Fiers and Xavier Saelens (VIB/UGent).

Unmet medical need
RSV is a respiratory virus that infects the lungs and breathing passages and most commonly affects the elderly, infants and patients with compromised immune systems. Globally, it is estimated that 64 million cases of RSV infection occur annually in all age groups, with 160,000 deaths. Marc Mansour (CEO Immunovaccine): “Currently, there is no vaccine available for the prevention of RSV, creating both a significant unmet medical need and a large vaccine market. A novel and effective vaccine formulated in a strongly immunogenic platform like DepoVax™ offers great potential for success.”

A new target
The new RSV vaccine candidate contains a unique target, a viral protein expressed on the surface of infected cells. Bert Schepens, Walter Fiers and Xavier Saelens discovered a way to turn this viral protein into a protective vaccine antigen. VIB/UGent’s IP rights on the resulting RSV vaccine candidate were exclusively in-licensed to Immunovaccine, a biotech company based in Canada that owns an interesting adjuvant platform. Preclinical studies clearly demonstrated the potential to curb RSV replication, the next necessary step were clinical trials. Xavier Saelens (VIB/UGent): "We developed this novel human RSV vaccine candidate and published our findings in EMBO Mol Med in 2014. We are excited to see Immunovaccine engage in this clinical trial to further advance the vaccine."

First results of the clinical Phase1 trial are promising
DPX-RSV, the candidate RSV vaccine, was well tolerated in the Phase 1 study’s first 20 healthy adults, of which 8 subjects received the DPX-RSV vaccine. Based on the vaccine candidate’s safety and immunogenicity demonstrated in the study, the independent Safety Review Committee (“SRC”) has allowed the study to proceed to the second part of this phase 1 trial, which includes vaccinating patients with DPXRSV at a higher dose. Bert Schepens (VIB/UGent): "We are very pleased with these first results from the clinical trial. It is an important step in actually translating our research into a real product of which a large group of people can benefit."

Schepens et al., EMBO Mol Med '14

Phase 1 - Evaluation of safety and immune response profile of the vaccine candidate in healthy adults.
The study, conducted at Dalhousie University, IWK Health Centre in Halifax, enrolls 40 healthy adults between 50 and 64 years of age. The vaccine will be tested at two different dose levels with one or two immunizations of each dose level. The low dose DPX-RSV was well tolerated. The next step can start: evaluation of a higher dose.

Phase 2 - Additional safety data and test whether the drug or vaccine is beneficial
In case of RSV 100 or more participants receive a vaccine before the RSV season (November-April in northern moderate climate zones), and are monitored for RSV-related symptoms. Another possibility is to challenge the participants with a GMP-produced RSV inoculum. At least one site in the United Kingdom can perform such a challenge and follow up the volunteers under quarantaine conditions.

Phase 3 - Test in large enough number of volunteers to obtain statistically sound results on the efficacy of the vaccine under field conditions. In a phase 3 trial up to 1000 or more volunteers are recruited. Safety profiling remains an important a