Cytomegalovirus Vaccine Flops in Mid-Stage Trial

Product fails to reduce CMV viremia compared with placebo

Disappointing results have been reported from a phase 2 trial evaluating the safety and efficacy of ASP0113 (Vical Incorporated/Astellas Pharma Inc.), a cytomegalovirus (CMV) vaccine, compared with that of placebo in kidney transplant patients receiving an organ from a CMV-seropositive donor. The study did not meet its primary endpoint––the proportion of patients with CMV viremia, defined as a plasma viral load of greater than or equal to 1,000 IU/mL, through one year after the first injection of study drug.

In addition, the secondary endpoints of CMV-associated disease and CMV-specific antiviral therapy were similar in both treatment groups. Safety profiles were also generally similar between groups. However, local injection-site reactions were more common among patients receiving the vaccine.

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 at centers in North America, Europe, and Australia. The participants were randomly assigned 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 solid organ transplant (SOT) and hematopoietic cell transplant (HCT) recipients. The bivalent DNA vaccine encodes CMV phosphoprotein 65 and glycoprotein B antigens for the induction of both cellular and humoral immune responses. ASP0113 was initially developed by Vical Incorporated, which is now in partnership with Astellas Pharma for further development and commercialization. ASP0113 has received an orphan drug designation from the FDA for the prevention of CMV disease in SOT and HCT recipients.

Source: Astellas Pharma; September 19, 2016.