SAN DIEGO and TOKYO - September 19, 2016 – Vical Incorporated (Nasdaq: VICL) and Astellas Pharma Inc. (TOKYO: 4503) today announced topline results from a randomized, double-blind, placebo-controlled Phase 2 study evaluating the safety and efficacy of cytomegalovirus (CMV) vaccine, ASP0113, versus placebo in kidney transplant patients receiving an organ from a CMV-seropositive donor. Results from the study demonstrated that the trial did not meet its primary endpoint, which was the proportion of patients having CMV viremia defined as a plasma viral load of ≥ 1000 IU/mL by central laboratory assay through one year after first injection of study drug. Additionally, the secondary endpoints of CMV-associated disease and CMV-specific antiviral therapy, which were evaluated by an independent, blinded Adjudication Committee, were similar in both treatment groups.
The safety profiles were generally similar between treatment groups. However, local injection site reactions were more common in the ASP0113 treatment group. Further detailed data from the trial is expected to be disclosed at an upcoming scientific congress.
"The unmet medical need in addressing CMV infection in transplant patients remains high. Although we had hoped for a different outcome, we look forward to further analyzing these data in hopes of contributing knowledge to the future development programs in this patient population,” said Bernhardt G. Zeiher, M.D., President, Development, Astellas. “In addition, we continue to focus on execution of our Phase 3 study in hematopoietic cell transplant (HCT) recipients and are pleased to announce that we have met our target enrollment.”
“We are pleased with our collaborative relationship with Astellas, and we look forward to the results from the pivotal Phase 3 study in HCT recipients, which we expect to obtain during the fourth quarter of 2017,” said Vijay Samant, President and Chief Executive Officer, Vical.
About the Study
The randomized, double-blind, placebo-controlled trial evaluated the safety and efficacy of ASP0113 in CMV-seronegative kidney transplant recipients receiving an organ from a CMV-seropositive donor (D+/R-). Enrollment included 150 kidney transplant recipients across approximately 80 centers in North America, Europe and Australia and randomized 1:1 to receive either ASP0113 or placebo, in addition to valganciclovir or ganciclovir prophylaxis for 100 days after kidney transplant.
ASP0113 is a vaccine designed to prevent CMV disease and associated complications in SOT and HCT recipients. The bivalent DNA vaccine encodes CMV phosphoprotein 65 and glycoprotein B antigens for induction of both cellular and humoral immune responses, formulated with a proprietary poloxamer-based delivery system. ASP0113 was initially developed by Vical and is now in partnership with Astellas for further development and commercialization. ASP0113 has received Orphan Drug Designation in the United States and Europe for the prevention of CMV disease in SOT and HCT recipients. The ongoing Phase 3 trial of ASP0113 in HCT recipients represents the first time a CMV vaccine or a DNA vaccine has entered Phase 3 testing in a registrational trial.
CMV is a herpes virus that infects more than half of all adults in the United States by age 50, and is even more widespread in developing countries. A healthy immune system typically protects an infected person against CMV disease, but does not prevent or clear latent infection. Individuals whose immune systems are not fully functional are at high risk of CMV reactivation, potentially leading to severe illness or death. Those at greatest risk include HCT and SOT recipients, as well as infants born to mothers who first become infected during pregnancy.