Another Vical vax flop, this time with Astellas-partnered CMV vaccine

Vical ($VICL) has notched another vaccine trial failure today after it posted new data showing its CMV vaccine ASP0113 couldn’t best placebo in helping kidney transplant patients with a form of the herpesvirus.

Microcap Vical and partner Astellas released data from their midstage trial pitting their cytomegalovirus (CMV) vaccine against placebo in kidney transplant patients receiving an organ from a CMV-seropositive donor. CMV, a common form of the herpesvirus, is estimated to affect up to 75% of all solid organ transplant recipients.

The virus can be passed on through an infected organ during a transplant, with these patients particularly at risk of developing CMV infection because they take meds that suppress their immune system, leaving them unable to fight off infection. 

But the data show that the experimental vax did not meet its primary endpoint, which was the number of patients having CMV viremia through one year after the first injection of the study drug.

It didn’t do much better in its secondary endpoints either, which showed that the CMV-associated disease and CMV-specific antiviral therapy was “similar in both treatment groups.” The companies said more data would be provided from the study in the future.

CMV used to be one of the main causes of illness and death during the first 6 months after an organ transplant, but antivirals have proved highly effective in preventing CMV infections in people who've received transplants. The next step is to develop vaccines for the virus, but this failure will be a blow to those plans.

Dr. Bernhardt Zeiher, president of development at Astellas, said: “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.”

This is a case of déjà vu for the biotech, which a few years ago saw a cancer vaccine flop a late-stage study, and then in 2015 neither its monovalent or bivalent vaccine hit the primary endpoint in a midstage herpes study.