- CMV neutralizing antibodies against fibroblast cell infection induced in 100% of subjects who received the highest dose
- Safe and well-tolerated at all doses with no safety signals observed
- Conference call and webcast today, Thursday, May 10, 2018, at 8:30 a.m. EDT
VBI Vaccines Inc. (VBIV) (“VBI”), today announced positive final top-line results from the randomized, placebo-controlled Phase 1 study of VBI-1501, the company’s prophylactic cytomegalovirus (CMV) vaccine candidate. VBI-1501 was developed using the company’s proprietary enveloped virus-like particle (eVLP) technology and presents a modified form of the glycoprotein B (gB) found on CMV. The final Phase 1 study results demonstrated that VBI-1501 was safe and well-tolerated at all doses. The highest dose of VBI-1501, 2.0μg, elicited protective CMV-neutralizing antibodies against fibroblast cell infection in 100% of subjects after the third vaccination, inducing titers comparable to those observed in patients protected as a result of natural infection. Neutralizing antibodies against epithelial cell infection were also seen in 31% of subjects receiving the same dose.
“These clinical results further demonstrate that our eVLP technology is a highly potent platform for antigen delivery that is safe and well-tolerated,” said Jeff Baxter, president and CEO of VBI. “We are extremely excited that we were able to show a robust immunologic response at a dose that is one-tenth the amount of other organizations’ CMV vaccine candidates. We believe this speaks to the unique antigen presentation capabilities of the eVLP platform. We look forward to the next stage of clinical development of VBI-1501 as we work diligently to address the significant unmet needs in CMV infection, a leading cause of birth defects worldwide.”
Final immunogenicity data from VBI’s Phase 1 study included gB antibody binding titers and neutralizing antibody seroconversion in both fibroblast and epithelial cells, two cell types CMV infects that are widely used to gauge the potency of CMV vaccine candidates.
- VBI-1501 induced gB antibody binding titers at all dose levels, with clear evidence of dose-dependent boosting after each vaccination.
- In fibroblast cells, the highest dose of VBI-1501 (2.0μg of gB-G content with alum) demonstrated an 85% neutralizing antibody seroconversion rate after two vaccinations and 100% after three vaccinations. Neutralizing antibody titers were comparable to those from CMV-positive controls (immunity induced by natural infection).
- In epithelial cells, which have historically been the much harder cell type to protect against infection, the highest dose of VBI-1501 with alum demonstrated a 31% neutralizing antibody seroconversion rate after three vaccinations, up from 17% after two vaccinations.
David E. Anderson, Ph.D., VBI Chief Scientific Officer, commented, “Given that CMV infects many cell types, one objective of our trial was to induce functional, neutralizing antibody responses that could block infection in multiple cell types. We are pleased to see activity against both fibroblast and epithelial cell infection, and expect that higher doses of VBI-1501 should further improve upon these positive and encouraging results.”
Joanne Langley, M.D., an Associate Director with the Canadian Center for Vaccinology located at Dalhousie University, the IWK Health Centre, and the Nova Scotia Health Authority, and Principal Investigator of the study further commented, “The safety profile of this vaccine is such that there is little concern about evaluating VBI-1501 at higher doses in the next stage of clinical development. With the functional activity we’ve seen, even at a low dose, these results are incredibly encouraging.”
About the Phase 1 Clinical Study
This study was a Phase 1 randomized, observer-blind, placebo-controlled study to evaluate the safety, tolerability, and immunogenicity of VBI’s preventative CMV vaccine in healthy adults. The study enrolled 125 CMV-negative participants, aged 18-40 years, who were randomized into five arms to receive various dose levels of a modified form of the CMV antigen gB, gB-G, with or without the adjuvant alum, or placebo:
- 0.5μg of gB-G content with alum (VBI-1501A 0.5μg)
- 1.0μg of gB-G content with alum (VBI-1501A 1.0μg)
- 1.0μg of gB-G content without alum (VBI-1501 1.0μg)
- 2.0μg of gB-G content with alum (VBI-1501A 2.0μg)
Participants were vaccinated at zero, two, and six months.
Additional information, including a detailed description of the study design, eligibility criteria, and investigator sites, is available at ClinicalTrials.gov using identifier NCT02826798.
Conference Call and Webcast Details
VBI Vaccines will host a conference call and webcast with accompanying slides today, Thursday, May 10, 2018 at 8:30 a.m. EDT.
The live webcast and slide presentation can be accessed via the Events /Presentations page in the Investors section of the Company’s website, www.vbivaccines.com, or by clicking this link: https://edge.media-server.com/m6/p/qkryg53t. A replay of the webcast will be available on the Company’s website for 90 days following the live conference call.
To listen to the live conference call, please dial:
- Toll-free U.S. & Canada Dial-In: 866-602-1050
- International Dial-In: 409-231-2052
- Conference ID: 7449919
CMV can cause serious disease in newborns when a mother is infected during pregnancy. Each year, approximately 5,000 U.S. infants will develop permanent problems due to CMV, which can include deafness, blindness, and developmental delays. CMV affects more live births than Down syndrome or fetal alcohol syndrome, making it a key public health priority and a strong candidate for recommended universal vaccination and reimbursement.