Effects of Interleukin-1β Inhibition on Incident Hip and Knee Replacement : Exploratory Analyses From a Randomized, Double-Blind, Placebo-Controlled Trial.

BACKGROUND

Osteoarthritis is a common inflammatory disorder with no disease-modifying therapies. Whether inhibition of interleukin-1β (IL-1β) can reduce the consequences of large joint osteoarthritis is unclear.

OBJECTIVE

To determine whether IL-1β inhibition with canakinumab reduces incident total hip or knee replacement (THR/TKR).

DESIGN

Exploratory analysis of a randomized trial. (ClinicalTrials.gov: NCT01327846).

SETTING

1091 clinical sites in 39 countries.

PARTICIPANTS

10 061 CANTOS (Canakinumab Anti-inflammatory Thrombosis Outcomes Study) participants.

INTERVENTION

Random allocation to placebo or canakinumab (50, 150, or 300 mg) subcutaneously once every 3 months.

MEASUREMENTS

The primary and secondary outcomes were time to first incident THR/TKR and time to first occurrence of an osteoarthritis-related adverse event (AE). Data were obtained through blinded ascertainment of trial clinical and safety databases.

RESULTS

Median follow-up was 3.7 years. For the individual canakinumab dose groups, compared with placebo, hazard ratios (HRs) for incident THR/TKR during follow-up were 0.60 (95% CI, 0.38 to 0.95) for the 50-mg group, 0.53 (CI, 0.33 to 0.84) for the 150-mg group, and 0.60 (CI, 0.38 to 0.93) for the 300-mg group. Thus, in the pooled canakinumab groups, compared with the placebo group, incidence rates for THR/TKR were 0.31 and 0.54 events per 100 person-years (HR, 0.58 [CI, 0.42 to 0.80];

LIMITATION

Because the parent trial was not designed to examine the efficacy of IL-1β inhibitors in osteoarthritis, information on structural joint outcomes was not collected.

CONCLUSION

Findings from this exploratory analysis of a randomized controlled trial support further investigation of IL-1β inhibition for treatment of large joint osteoarthritis.

PRIMARY FUNDING SOURCE

Novartis Pharmaceuticals.