Interleukin (IL)-1β is considered a shared pathogenic mediator between rheumatoid arthritis (RA) and type 2 diabetes (T2D). In the TRACK study, participants with both diseases were randomised to an IL-1 inhibitor, anakinra, or a TNF inhibitor (TNFi). After 6 months, anakinra induced a such of improvement on metabolic and inflammatory parameters, leading to a premature stoppage of the study. Thus, we aimed to assess how long IL-1 inhibition benefits lasted.
Since the TRACK was prematurely discontinued for "early benefit", we furtherly followed-up the enrolled participants to assess how long persisted the improvement of glycated haemoglobin (HbA1c%) and of RA disease activity.
After a mean follow-up of 18 months (15 participants in anakinra-group and 14 in TNFi-group), RA clinical response was retained in both groups (DAS28: 2.59±1.01 vs. 2.88±0.91; p=0.109). Concomitant glucocorticoids were reduced in both groups (2.01±0.71 vs. 3.01±0.87 mg/die; p=0.124), but a larger percentage of anakinra-treated participants discontinued such drugs (53.3% vs. 28.6%; p=0.004). There was no difference between anakinra and TNFi for HbA1c% (6.60±0.52 vs. 6.79±0.43; p=0.291), but a reduction of anti-diabetic drugs was observed in anakinra-treated participants (53.3% vs. 7.1%; p=0.008) whereas an increase of anti-diabetic therapies was needed in TNFi-treated ones. Significant correlations were also observed among HbA1c% with DAS28 and with C-reactive protein. Analysing the safety profile, only minor side effects were recorded.
Data deriving from the long-term extension of participants with RA and T2D, enrolled in the TRACK study, could suggest that the benefits of IL-1 inhibition on metabolic and inflammatory parameters could last longer than first 6 months of follow-up, but further studies are needed to confirm these findings.