Imaging atlas for eligibility and on-study safety of potential hip adverse events in anti-NGF studies (Part 2)

Abstract

Recently, nerve growth factor (NGF) inhibitors have been introduced for treatment of osteoarthritis (OA) symptoms, and have shown good analgesic efficacy and improvement in function in patients with OA. However, anti- (a-)NGF trials in OA had been suspended by the U.S. Food and Drug Administration (FDA) due to concerns over accelerated rates of OA progression and osteonecrosis. Since a-NGF therapies offer potential as the first new class of analgesics for many years, future studies assessing a-NGF compounds will have to follow stringent eligibility criteria and will require a rigorous safety monitoring. Imaging is paramount to identify potential negative outcomes as early as possible. These imaging findings include atrophic OA, osteonecrosis and others at eligibility and especially rapid progressive OA (RPOA) during the course of treatment. This second part of the a-NGF imaging atlas will present specific hip joint imaging findings that are relevant for eligibility and safety and represent potential adverse joint events on radiography and magnetic resonance imaging (MRI) in studies investigating a-NGF compounds. Researchers and clinicians should become familiar with several of these entities, and especially osteonecrosis of the hip and insufficiency fractures are relatively common findings in such a patient population. As several of these diagnoses may only be detected at late stages using radiographic methods, MRI plays an important role in identifying such pathologies early and at potentially still reversible stages before irreversible joint destruction has occurred.