Promising Phase II Data Reported for Antiviral Drug Brincidofovir
Drug treats CMV infection in transplant recipients (September 26)
Promising results have been reported from a phase II study of brincidofovir (Chimerix, Inc.) for the prevention of cytomegalovirus (CMV) infection in hematopoietic cell transplant (HCT) recipients. The new findings were published in the New England Journal of Medicine.
Brincidofovir is an investigational oral nucleotide analog lipid-conjugate that has shown broad-spectrum antiviral activity against double-stranded DNA (dsDNA) viruses, including CMV. The new study –– a randomized, placebo-controlled, double-blind, dose-escalation trial in 230 subjects –– met the primary endpoint of a reduction in CMV viremia and/or CMV disease for brincidofovir 100 mg twice weekly versus placebo (P = 0.002).
Based on these results, a phase III trial (SUPPRESS) has been initiated to evaluate brincidofovir 100 mg twice weekly for the prevention of CMV infection in HCT recipients.
The phase II study was a randomized, double-blind, placebo-controlled, dose-escalation trial that evaluated the safety, tolerability, and efficacy of brincidofovir in the prevention or control of CMV disease in 230 allogeneic HCT recipients at high risk of CMV infection.
Following engraftment, or evidence of successful production of new blood cells by the new bone marrow, the subjects were randomized into five sequential, dose-escalating cohorts to receive either brincidofovir or placebo at doses ranging from 40 mg once weekly to 200 mg twice weekly. The subjects were treated for nine to 11 weeks through post-transplant week 13, after which they were followed for an additional 4 to 8 weeks.
The study’s primary endpoint was the incidence of CMV disease at any time during therapy or a CMV polymerase chain reaction (PCR) assay result of greater than 200 copies/mL (the lower limit of quantification of the assay) at the time of the last dose of study drug.
All brincidofovir doses and dose regimens showed antiviral activity compared with placebo, except for the lowest dose (40 mg once weekly). The proportion of subjects who developed CMV disease or a CMV PCR positive result at the end of the 100-mg twice weekly dosing period was 10% (five of 50) versus 37% (22 of 59) in the placebo-treated group (P = 0.002).[Source: Chimerix, Inc., September 26, 2013]