Stevenage-based pharmaceutical company AKL Research and Development has announced it has signed an agreement with one of the world’s top five animal health companies to fund the development of its next-stage clinical trial of an investigational drug called APPA in the treatment of canine osteoarthritis (OA).

APPA is an oral, patented, fixed-dose combination of two synthetic secondary metabolites of plant origin, apocynin and paenol.

Under the terms of the agreement, AKL’s unnamed partner will fund a study in dogs with naturally occurring OA. The study will compare the efficacy and efficacy duration of APPA with the current standard of care for treating canine OA: non-steroidal anti-inflammatory drugs

David Miles, AKLRD CEO, said: “Just like humans, millions of dogs suffer intolerable pain and disability because of OA and the current treatments just aren’t as effective or as well tolerated as they need to be. We already know from previous canine studies that APPA reduces pain and has an excellent tolerability profile but this exciting new partnership will allow us to go one stage further and assess sustainability of response.”

The randomised study will assess pain and duration of response as the primary endpoint. Secondary endpoint assessment will include adverse events, quality of life, pharmacokinetics analysis and biomarkers that may enable potential identification of factors predictive of response at treatment onset, or that correlate with response magnitude.

Two separate studies on dogs have already been carried out by researchers at the University of Vienna. The first, an 11-week cross-over study of 32 canines diagnosed with established, naturally occurring OA, showed that APPA provides significant symptom relief in clinical canine OA1.

A follow-up, five-week study of 60 dogs with OA compared APPA to the standard of care drug, meloxicam. It concluded that daily oral administration of APPA was effective as a stand-alone alternative to NSAIDs in dogs with naturally occurring OA. Significant benefits were also seen for APPA over meloxicam in orthopaedic examination as well as in lameness and function scores2.

The results will inform the pivotal clinical trial design and AKL says its working assumption is that a 26-week field study would complete the regulatory requirements for commercialisation.

If the study and future testing is successful, AKL estimates that APPA would be well placed to capture a significant share of the global canine OA market, which is estimated to be worth $3billion by 20283.


  1. Glasson S, Larkins N. APPA provides symptom relief in clinical canine osteoarthritis. Osteoarthritis and Cartilage. 1, S287, April 01, 2012.
  2. Larkins N, King C. Effectiveness of apocynin-paeonol (APPA) for the management of osteoarthritis in dogs: comparisons with placebo and meloxicam in client-owned dogs. Matters. 2017. DOI: 10.19185/matters.201608000001201608000001
  3. Cision. PR Newswire. NSAIDs to Treat Arthritis Canines Through 2028; Stem Cell Therapies to Invigorate Canine Arthritis Treatment Market. 6 August 2018. [Accessed 15 July 2020]

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