NEW trial data suggest that diacerein does not improve pain in patients with knee osteoarthritis (OA), even among those with an inflammatory phenotype, challenging its role as a targeted treatment option.
The randomised, double-blind, placebo-controlled study evaluated the efficacy of diacerein, an interleukin-1β inhibitor, in patients with symptomatic knee OA and MRI-confirmed effusion-synovitis.
Targeting Inflammation in OA
Inflammation is increasingly recognised as a key contributor to pain and disease progression in a subset of OA patients. Diacerein, which inhibits IL-1β activity, has been proposed as a potential treatment for this inflammatory phenotype.
To test this, researchers enrolled 262 adults with knee OA, significant pain, and imaging evidence of joint inflammation across four centres in Australia. Participants were randomised to receive diacerein or placebo for 24 weeks.
No Significant Pain Improvement
At the end of the study period, both groups experienced reductions in knee pain. However, there was no meaningful difference between diacerein and placebo. The between-group difference in pain scores was small and not clinically significant, falling well below the threshold for meaningful improvement.
These findings indicate that targeting IL-1β with diacerein does not translate into better pain outcomes, even in patients selected for inflammatory features.
Higher Rate of Adverse Events
Patients receiving diacerein experienced a higher frequency of adverse events, particularly gastrointestinal symptoms. Diarrhoea was notably more common in the treatment group, and some patients also reported changes in urine colour.
Although no major safety concerns emerged, the higher burden of side effects further limits the clinical appeal of the drug in this setting.
Implications for Treatment Strategies
The results highlight the ongoing challenge of developing effective pharmacological treatments for knee OA, particularly for patients with inflammatory features. While biologically targeted therapies remain an area of interest, this study suggests that IL-1 inhibition with diacerein is unlikely to provide meaningful benefit.
Looking Ahead
The authors conclude that diacerein should not be recommended for improving knee pain in patients with inflammatory knee OA. Future research will need to explore alternative pathways and more effective strategies for managing this complex and highly prevalent condition.
