Although improvement in total Western Ontario and McMaster Universities Osteoarthritis Index scores were seen in the patients with knee OA, there was no real differentiation by dose or by placebo. The rationale for having a longer trial follow-up – the last dose of sprifermin was given at 18 months – is to see if there is a later effect.
In the later stages of development is Invossa TissueGene-C; this is drug that consists of patients’ normal and genetically-modified chondrocyte cells that express transforming growth factor-beta 1. Phase 2 findings have shown that it can improve pain and function scores in patients with moderate to advanced knee OA (BMC Musculoskelet Disord. 2017;18[1]:461). Based on those findings, two phase 3 trials are currently underway, with some further findings presented elsewhere at the OARSI meeting.
Even though there is still no disease-modifying osteoarthritis drug currently licensed for use, “I’m really positive about all of what we’ve learned, particularly with the application to future trials and ongoing trials in this space,” Dr. Hunter observed.
“Future strategies should differentiate between those agents aiming to reduce pain, and those targeting structural evolution, incorporating a combination of anabolic and anti-catabolic therapies,” Dr. Hunter suggested. One of the challenges, however, is to address the placebo effect, which can be exaggerated by the context of administration or surgery.