Background Pain is the primary symptom of concern for patients with osteoarthritis (OA). Numerous studies have shown that pain control is frequently inadequate for people with symptomatic OA. Furthermore, the use of recommended medications such as paracetamol, low dose opiates and Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are frequently associated with adverse effects, especially in older people. Not surprisingly, OA patients are high users of complementary and alternative medicines. In the past, extracts of the New Zealand green-lipped mussel (GLM, perna canaliculus) have been investigated in small-scale studies as a potential therapy for pain in OA. In this study, a novel GLM lipid extract, BioLex™, was investigated. This formulation is manufactured to retain high concentrations of bioactive lipids, including the more recently described N-palmitoylethanolamide (PEA) and other N-acylethanolamine (NAE) compounds.

Objectives To undertake a randomized double-blind placebo controlled trial of a GLM- BioLex™-assessing potential impacts on pain and quality of life in OA.

Methods 80 patients fulfilling the American College of Rheumatology criteria for OA of the hip or knee were randomized to receive either 4 capsules (600mg) of BioLex™ daily or identical placebo (corn oil) for 12 weeks. All participants, assessors and investigators were blinded to the radomization. Entry criteria included a minimum 100mm Visual Analogue pain Score (VAS) of 30mm at baseline.

The primary outcome was pain, measured by the Western Ontario and McMasters OA Index (WOMAC) pain subscale and VAS pain scale. Secondary outcome measures included: quality of life (OAQol questionnaire), total WOMAC score, WOMAC-20 responder criteria and medication use over the study period (paracetamol and NSAIDs).

Participants were assessed at baseline, 12 weeks (end of therapy) and 15 weeks (post intervention).

Results Mean (±SD) age of participants was 66.4 years (±10.0) with 45% male. Of the 80 participants, baseline X-rays demonstrated severe radiographic OA in 58 patients (73%), who had Kellgren Lawrence grades of 3 or 4.

At week 12, no statistically significant between group difference in VAS or WOMAC pain subscale scores were noted, nor was there evidence of relative improvements in the WOMAC-20 responder criteria or OAQol. At week 15 (post-intervention) joint stiffness (measured by WOMAC-B) in the BioLex™ group improved relative to placebo (p=0.046) and there was a significant reduction in the use of paracetamol (p=0.001).

No serious adverse events were reported.

Conclusions Although no clinical benefit from BioLex™ was demonstrated in either the primary or secondary outcomes in the OA group compared with placebo over the intervention period, there was a signifcant reduction in paracetamol use and joint stiffness in the post intervention period. Higher doses of BioLex™ or longer treatment periods are worthy of further investigation.

Disclosure of Interest S. Stebbings: None declared, A. Gray: None declared, A. Schneiders: None declared, A. Sansom Employee of: Seperex nutitionals

DOI 10.1136/annrheumdis-2014-eular.3398