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A scientific article titled “AM-111 reduces hearing loss in a guinea pig model of acute labyrinthitis” in the December 2007 issue of the American journal Laryngoscope is presenting new data on AM-111, Auris Medical’s intracellular apoptosis inhibitor
DUEDINGEN, Switzerland | January 13, 2008 | A scientific article titled “AM-111 reduces hearing loss in a guinea pig model of acute labyrinthitis” in the December 2007 issue of the American journal Laryngoscope is presenting new data on AM-111, Auris Medical’s intracellular apoptosis inhibitor. It contains the main results of a study which was conducted jointly by the University of California at San Diego, the Veterans Medical Research Foundation and Auris Medical, and directed by Elizabeth M. Keithley, PhD.
The study evaluated the otoprotective effects of AM-111 in a model of acute labyrinthitis, which is characterized by an exuberant inflammatory response in the inner ear. Acute labyrinthitis may be induced by a bacterial or viral infection and result in hearing loss, dizziness, loss of balance, tinnitus or involuntary eye movements. For the study, sterile labyrinthitis was induced in guinea pigs through systemic sensitization with keyhole limpet hemocyanide (KLH), followed later by intracochlear KLH administration. This resulted in a vigorous inflammatory response and significant sensorineural hearing loss (> 70 dB after three days). AM-111 was delivered in a 100 μL gel formulation onto the round window membrane at a concentration of either 1, 10 or 100 μM immediately after intracochlear KLH administration.
The study showed a dose dependent otoprotective effect of AM-111 in acute labyrinthitis. At 100 μ M, the most effective dose, the hearing loss 21 days after induction of acute labyrinthitis was statistically significantly lower in AM-111 treated ears than in untreated control ears (39 vs. 68 dB; p < 0.03, one-way ANOVA). At the same time, the mean loss of distortion product otoacoustic emission (DPOAE) from labyrinthitis was reduced from 64 dB to 40 dB (p< 0.02). Histopathology demonstrated a significantly higher percentage of inner hair cell survival (p < 0.04), a trend for marked reduction of outer hair cell loss, and significantly higher density of spiral ganglion neurons (p < 0.001) in animals receiving the highest concentration of AM-111 compared with untreated controls.
These results provide further evidence for apoptosis inhibition by AM-111 at the hair cell or spiral ganglion level in case of inner ear insults. This inhibition may be partially also the result of a direct anti-inflammatory effect of the drug. Histology revealed a significant reduction in leukocytes on day 21 in AM-111 treated ears (p < 0.01), and showed in general less inflammatory tissue damage. These findings suggest a potential therapeutic effect of AM-111 in a variety of inner ear disorders involving exuberant inflammatory responses.
SOURCE: Auris Medical |
