Parnell Pharmaceuticals Holdings Ltd. announced that Zydax, Parnell's osteoarthritis (OA) therapeutic being developed for dogs and horses, demonstrated a significant improvement in clinical signs of osteoarthritis in dogs in a pivotal clinical efficacy trial. In previous mechanism of action studies, Zydax has been shown to uniquely inhibit Aggrecanase-1, the enzyme understood to be the primary cause of degenerative joint disease and to stimulate proteoglycan synthesis necessary for cartilage regeneration. Key highlights of the trial results include: Using a validated measure for assessing changes in the clinical signs of osteoarthritis, Zydax treated dogs achieved significant improvements in mobility.

Dog owners used the Client Specific Outcome Measures (CSOM) tool to quantify an Activity Impairment Score (AIS) to track changes in their dogs' mobility. At 14 days, Zydax treated dogs achieved an AIS reduction of 2 (20% improvement; p=0.04 vs. placebo) and at 28 days an AIS reduction of 3 (30% improvement; p=0.01 vs.

placebo). The Primary End-Point for the trial was a reduction of 3 or more in the Activity Impairment Score; 56% of Zydax treated dogs achieved this end-point vs. 40% for placebo (p=0.02).

Additional trial analysis assessed the spectrum of responses in dogs with early to mid-stage clinical signs of osteoarthritis at enrollment. Zydax treated dogs demonstrated a range of improvements in AIS; after 28 days of treatment with Zydax, 81% of dogs achieved at least an 11% improvement (AIS reduction of =1; p=0.02) while 23% of dogs achieved more than 56% improvement (AIS reduction of =5; p=0.03).