Prevalence of preexisting articular bone pathology in patients with osteoarthritis screened for fasinumab clinical trials identified by X-ray or magnetic resonance imaging

Objective

To examine the prevalence of preexisting articular bone pathology in patients with hip or knee pain due to osteoarthritis (OA) screened for fasinumab clinical trials.

Method

This post-hoc analysis included patients with OA screened for three phase 3 fasinumab studies (NCT02683239, NCT03161093, NCT03304379). During screening, participants who met other clinical inclusion/exclusion criteria underwent radiography of knees, hips, and shoulders. Those with Kellgren–Lawrence grade (KLG) ≥ 2 for index joint and without an exclusionary finding proceeded to magnetic resonance imaging (MRI) of index, contralateral, and KLG ≥ 3 joints. Exclusionary findings included bone fragmentation/collapse, bone loss/resorption, osteonecrosis, and fracture, by either X-ray or MRI. Participants with extensive subchondral cysts were also excluded. Prevalence of abnormalities on radiographs and MRIs are reported.

Results

Of 27,633 participants screened, 21,997 proceeded to imaging. Of these, 1203 (5.5%) were excluded due to the presence of ≥ 1 joint with severe articular bone pathology (X-ray or MRI): bone fragmentation/collapse (2.60%), subchondral insufficiency fracture (SIF; 1.67%), osteonecrosis (1.11%), and significant bone loss (0.32%). Additionally, 3.13% screen-failed due to extensive subchondral cysts. More than half of the exclusions due to bone fragmentation/collapse (386/572), osteonecrosis (141/245) and significant bone loss (59/71), and approximately one third of SIF (133/367) and extensive subchondral cysts (229/689) were evident on X-rays.

Conclusions

Approximately one in 20 participants with OA who met the clinical screening criteria for fasinumab phase 3 trials were later excluded due to preexisting severe articular bone pathology findings by X-ray or MRI.