Pilot Evaluation of The Effect of Anti-nerve Growth Factor Antibody on Sensory System Function in Dogs with Degenerative Joint Disease-Associated Pain

 

Introduction: There is a critical need for novel analgesics for the treatment of degenerative joint disease (DJD) pain in dogs. Antibodies against Nerve Growth Factor (anti-NGF-Ab) are analgesic in rodent models, naturally occurring DJD-pain in dogs, and chronic pain in humans. However, some humans report side effects of paresthesia, hypoesthesia or hyperesthesia.

Methods: The aim of this blinded, randomized, placebo-controlled pilot study was to evaluate sensory system function in dogs with DJD-associated chronic pain following a single dose of anti-NGF-Ab (200 µg/kg IV) (n = 10), or an equal volume saline injection (placebo) (n = 13), using quantitative sensory testing (QST) as a non-invasive method for identifying both sensory loss and gain. Mechanical (Electronic von Frey [EVF] and blunt pressure) and thermal (hot) sensory thresholds were obtained in dogs with DJD-associated pain at Day 0 and 28 days following treatment.

Results: There was not a significant difference over time for any QST modalities in the anti-NGF-Ab group. EVF, blunt pressure thresholds and hot thermal thresholds were not significantly different after 28 days (p = 0.141, p = 0.155 and p = 1.00 respectively). However, in the control group, EVF, blunt pressure and hot thermal thresholds were significantly decreased after 28 days (p = 0.002, p = 0.007 and p = 0.004 respectively).

Conclusions: Our results indicate that no loss of gain of sensation was observed after administration of anti-NGF-Ab, but hyperalgesia was seen in the control group. Further work is needed to determine if the different group differences represent relative hypoalgesia in the anti-NGF-Ab group, or a reversal of central sensitization due to effective analgesia.

Acknowledgement: Funding source: Nexvet Biopharma Pty Ltd (now owned by Zoetis, NJ, United States).