DRACO drug effective against most viruses (Double-stranded RNA Activated Caspase Oligomerizer)

"New drug could cure nearly any viral infection", proclaimed the media. The drug works by targeting a type of RNA (dsRNA) produced only in cells that have been infected by viruses. “In theory, it should work against all viruses."

Currently there are relatively few antiviral therapeutics, and most which do exist are highly pathogen-specific.

The MIT researchers developed a new broad-spectrum antiviral approach, called Double-stranded RNA (dsRNA) Activated Caspase Oligomerizer (DRACO).

DRACO selectively induces apoptosis in cells containing viral dsRNA, rapidly killing infected cells without harming uninfected cells.

The drugs were nontoxic to mammalian cells and effective against 15 different viruses, including dengue flavivirus, arenaviruses, bunyavirus, and H1N1 influenza. Dengue fever has invaded Florida and there are no effective antiviral agents to treat dengue infection at this time, according to a recent NEJM review (http://goo.gl/0gEXH).

DRACOs have the potential to be effective therapeutics or prophylactics for numerous clinical and priority viruses, due to:

- broad-spectrum sensitivity of the dsRNA detection domain
- potent activity of the apoptosis induction domain



NPR Video: How a Flu Virus Invades Your Body: "It starts very simply. A virus, just one, latches on to one of your cells and fools that cell into making lots more. Lots, lots more, like a million new viruses. This animation shows you how viruses trick healthy cells to join the dark side".

References:

New drug could cure nearly any viral infection. MIT News.

Rider TH, Zook CE, Boettcher TL, Wick ST, Pancoast JS, et al. (2011) Broad-Spectrum Antiviral Therapeutics. PLoS ONE 6(7): e22572. doi:10.1371/journal.pone.0022572

Monoclonal antibodies against C. difficile toxins reduce recurrence of the infection

New therapies are needed to manage the increasing incidence, severity, and high rate of recurrence of Clostridium difficile infection.

A randomized, double-blind, placebo-controlled study included 2 neutralizing, fully human monoclonal antibodies against C. difficile toxins A (CDA1) and B (CDB1). The antibodies were administered together as a single infusion, each at a dose of 10 mg per kilogram of body weight, in patients with symptomatic C. difficile infection who were receiving either metronidazole or vancomycin.

Among the 200 patients who were enrolled (101 in the antibody group and 99 in the placebo group), the rate of recurrence of C. difficile infection was lower among patients treated with monoclonal antibodies (7% vs. 25%).

However, the mean duration of the initial hospitalization for inpatients did not differ significantly between the antibody and placebo groups (9.5 and 9.4 days, respectively).

The addition of monoclonal antibodies against C. difficile toxins to antibiotic agents significantly reduced the recurrence of C. difficile infection.

My opinion: It is always encouraging to add new tools to the treatment armamentarium aimed at defeating dangerous infections such as C. diff. colitis. However, monoclonal antibodies are generally very expensive and require intravenous administration.

References:

Treatment with Monoclonal Antibodies against Clostridium difficile Toxins. Israel Lowy. NEJM Volume 362:197-205 January 21, 2010 Number 3.

No antibitoc is superior for initial cure of C. difficile infection. Recurrence is less frequent with fidaxomicin http://goo.gl/dBRDj

Image source: Micrograph of a colonic pseudomembrane in Clostridium difficile colitis, a type of pseudomembranous colitis. H&E stain. Wikipedia, Nephron, Creative Commons Attribution-Share Alike 3.0 Unported license.