Safety of ASP0113, a cytomegalovirus DNA vaccine, in recipients undergoing allogeneic hematopoietic cell transplantation: an open-label phase 2 trial

Cytomegalovirus (CMV) infection/reactivation is a serious complication after hematopoietic cell transplantation (HCT). The DNA vaccine ASP0113 contains two plasmids encoding CMV antigens (glycoprotein B and tegument phosphoprotein 65) that stimulate humoral and cellular immunity. Between June 2013 and February 2014, Astellas conducted a phase 2, open-label, uncontrolled, three-center trial to investigate the safety and tolerability of ASP0113 in Japanese patients undergoing HCT for hematologic disorders. Ten patients aged 22–61 years were enrolled; nine received at least one dose of ASP0113. Six patients received all five doses of ASP0113 5 mg at intervals before and after HCT. Pre-emptive antiviral therapy was allowed. One patient died following relapse of primary disease. All patients had serious adverse events deemed unrelated to ASP0113. CMV viremia (assessed by CMV antigenemia) occurred in seven patients, who then received anti-CMV therapy. No patients developed CMV end-organ disease. Adverse events associated with ASP0113 injection included pyrexia (three patients), skin reactions [injection site pain, injection site tenderness, and erythema (two patients each); and rash, injection site erythema, injection site induration, and injection site swelling (one patient each)], and hyperuricemia (one patient). ASP0113 was well tolerated in Japanese HCT recipients. Further studies should evaluate its efficacy and safety.