Symptomatic and structural benefit of cathepsin K inhibition by MIV-711 in a subgroup with unilateral pain: post-hoc analysis of a randomised phase 2a clinical trial.

OBJECTIVES: Osteoarthritis (OA) development programmes face challenges due to discordance between structural changes and symptoms. A novel cathepsin-K inhibitor, MIV-711, recently reported structural benefits, but did not demonstrate a significant difference from placebo in symptoms. Previous work suggests that pain from non-target joints may confound OA pain outcomes. We therefore conducted an exploratory analysis in participants with predominantly unilateral knee pain from the MIV-711-201 trial. METHOSD: Participants scoring below median contralateral knee NRS pain at baseline from the MIV-711-201 phase 2a clinical trial (n=119) were analysed by treatment group for differences in change from baseline in WOMAC pain, quantitative magnetic resonance imaging bone area and cartilage thickness with a repeated-measures mixed model adjusting for relevant co-variates. RESULTS: In the subgroup with unilateral knee pain, treatment with MIV-711 100 mg led to greater reduction in WOMAC pain compared to placebo (-5.0, 95% CI: -8.69 to -1.3, p=0.008), while 200 mg did not (-2.5, 95% CI: -6.5 to 1.6, p=0.23). MIV-711 treatment was associated with a reduced change in bone area compared to placebo (200 mg; -19.6 mm2 , 95% CI: -36.2 to -3.0, p=0.02, and 100 mg; -12.5 mm2 , 95% CI: -27.8 to 2.8, p=0.11,). No observed differences between treatment groups in cartilage thickness were found in this subgroup. CONCLUSIONS: In a subgroup with predominantly unilateral knee pain, significant reduction in OA pain by MIV-711 100 mg treatment was found, with concurrent beneficial structural effects, highlighting the importance of appropriate pain inclusion criteria in OA trials.

The relationship between three-dimensional knee MRI bone shape and total knee replacement-a case control study: data from the Osteoarthritis Initiative.

OBJECTIVE: There is growing understanding of the importance of bone in OA. Our aim was to determine the relationship between 3D MRI bone shape and total knee replacement (TKR). METHODS: A nested case-control study within the Osteoarthritis Initiative cohort identified case knees with confirmed TKR for OA and controls that were matched using propensity scores. Active appearance modelling quantification of the bone shape of all knee bones identified vectors between knees having or not having OA. Vectors were scaled such that -1 and +1 represented the mean non-OA and mean OA shapes. RESULTS: Compared to controls (n = 310), TKR cases (n = 310) had a more positive mean baseline 3D bone shape vector, indicating more advanced structural OA, for the femur [mean 0.98 vs -0.11; difference (95% CI) 1.10 (0.88, 1.31)], tibia [mean 0.86 vs -0.07; difference (95% CI) 0.94 (0.72, 1.16)] and patella [mean 0.95 vs 0.03; difference (95% CI) 0.92 (0.65, 1.20)]. Odds ratios (95% CI) for TKR per normalized unit of 3D bone shape vector for the femur, tibia and patella were: 1.85 (1.59, 2.16), 1.64 (1.42, 1.89) and 1.36 (1.22, 1.50), respectively, all P < 0.001. After including Kellgren-Lawrence grade in a multivariable analysis, only the femur 3D shape vector remained significantly associated with TKR [odds ratio 1.24 (1.02, 1.51)]. CONCLUSION: 3D bone shape was associated with the endpoint of this study, TKR, with femoral shape being most associated. This study contributes to the validation of quantitative MRI bone biomarkers for OA structure-modification trials.

A systematic review of the relationship between subchondral bone features, pain and structural pathology in peripheral joint osteoarthritis.

INTRODUCTION: Bone is an integral part of the osteoarthritis (OA) process. We conducted a systematic literature review in order to understand the relationship between non-conventional radiographic imaging of subchondral bone, pain, structural pathology and joint replacement in peripheral joint OA. METHODS: A search of the Medline, EMBASE and Cochrane library databases was performed for original articles reporting association between non-conventional radiographic imaging-assessed subchondral bone pathologies and joint replacement, pain or structural progression in knee, hip, hand, ankle and foot OA. Each association was qualitatively characterised by a synthesis of the data from each analysis based upon study design, adequacy of covariate adjustment and quality scoring. RESULTS: In total 2456 abstracts were screened and 139 papers were included (70 cross-sectional, 71 longitudinal analyses; 116 knee, 15 hip, six hand, two ankle and involved 113 MRI, eight DXA, four CT, eight scintigraphic and eight 2D shape analyses). BMLs, osteophytes and bone shape were independently associated with structural progression or joint replacement. BMLs and bone shape were independently associated with longitudinal change in pain and incident frequent knee pain respectively. CONCLUSION: Subchondral bone features have independent associations with structural progression, pain and joint replacement in peripheral OA in the hip and hand but especially in the knee. For peripheral OA sites other than the knee, there are fewer associations and independent associations of bone pathologies with these important OA outcomes which may reflect fewer studies; for example the foot and ankle were poorly studied. Subchondral OA bone appears to be a relevant therapeutic target. SYSTEMATIC REVIEW: PROSPERO registration number: CRD 42013005009.