FLEXISEQ for osteoarthritis

The technology described in this briefing is FLEXISEQ, a topically applied drug-free gel indicated for treating the symptoms of osteoarthritis. A potential innovative aspect is that it is described as having a novel, physical mode of action and contains no active drug. It consists of an aqueous gel containing hydrophilic, nanoscale lipid vesicles made from phospholipid bilayer (Sequessome vesicles), which are designed to pass through the skin into the joint. FLEXISEQ is regulated as a medical device.

The intended place in therapy is as a pain-relieving treatment for people with all stages of osteoarthritis, especially those for whom non-steroidal anti-inflammatory drugs (NSAIDS) are not suitable. It would be used in addition to core treatments such as exercise and weight loss.

The key points from the evidence summarised in this briefing are from 4 randomised controlled trials (RCTs), including a total of 3,213 patients with knee osteoarthritis, and a meta-analysis. The RCTs, in which FLEXISEQ was used as the placebo arm for studies of topical ketoprofen and oral celecoxib, showed that FLEXISEQ was, in some cases, at least non-inferior to active comparators. The meta-analysis reported that the magnitude of the effect with FLEXISEQ is unlikely to be a result of the placebo effect alone.

Key uncertainties are the limited evidence base for FLEXISEQ's analgesic mode of action and the major limitation of all trials in that there was no topical placebo control (inactive gel) with which to compare the effectiveness of FLEXISEQ. The meta-analysis was of poor methodological quality. A randomised controlled trial comparing FLEXISEQ to a topical gel placebo in people with knee osteoarthritis is currently ongoing with results expected in late 2016.

FLEXISEQ is not yet available on the NHS, but the current retail cost for a 50 g tube bought over the counter is about £18.00, including VAT.