The biologic adalimumab (Humira) has no effect on pain or structural abnormalities in people with erosive hand osteoarthritis, an Australian randomised placebo controlled trial concludes.

According to the team of rheumatologists led by Professor Graeme Jones from the Menzies Institute for Medical Research in Tasmania, the findings indicate that TNF-alpha may not be the right treatment target in people with osteoarthritis.

The trial involved 43 patients who were randomised to receive a 40mg subcutaneous injection of adalimumab every other week or identical placebo injections for 12 weeks. Following an 8 week washout period patients were then crossed over to the other treatment group.

Results showed that the main clinical outcome — change over 12 weeks as assessed by VAS score — was not different between the two groups (mean decrease in VAS pain of 3.2mm 40 (SD 16.7) for adalimumab versus 0.8mm (SD 29.6) for placebo).

No clinically or statistically significant differences were seen found for patient-reported outcomes and MRI-assessed structural abnormalities (synovitis and BMLs).

“Unlike RA, inflammation in OA may be present as a result of joint damage as opposed to primary immune activation,” the research team concluded in their paper published in Osteoarthritis and Cartilage.

“It may not be driving the disease but rather represent a consequence of the disease process,” they said.