Cartilage is a curious tissue in the human body. While acting as a “springboard” and cushion for our bones to articulate, it tends to take a substantial beating over our lifetime. And cartilage, unfortunately, does not have its own blood supply—after cartilage cells (a.k.a. chondrocytes) are sloughed off over time from wear and tear, they can’t recover or regenerate like the skin and other body cells. This phenomenon creates the all-too-familiar pathology of osteoarthritis.

Perhaps the joint most recognized for osteoarthritis as we age is the knee joint. Some prevalence estimates place knee osteoarthritis in nearly 40 percent of adults in the US over the age of 60. This is a tremendous burden, with potentially tens of millions of individuals suffering without any definitive cure. 

While cartilage regeneration is certainly of interest to many researchers around the globe, the majority of these potential therapies are still being tested in the “pre-clinical” realm (e.g., in vivo animal models or in vitro cell/tissue assays). However, there may be alternative routes to curbing this destructive and pervasive pathology of knee osteoarthritis—and it may be right around the corner at Utah-based Merit Medical.

Merit Medical Systems, Inc. announced in April 2022 that it received “breakthrough device designation” from the US Food & Drug Administration (FDA) for Embosphere® Microspheres for the targeted treatment of symptomatic knee osteoarthritis. This treatment works by blocking the blood flow to parts of the knee causing pain, decreasing the amount of inflammation, and allowing for more normal function of the knee joint despite destroying the cartilage “cushion” between the bones. As a market-leading solution in embolotherapy, Embosphere Microspheres are the most clinically utilized and studied spherical embolic. Embosphere Microspheres have been used in patients over the past 20+ years in more than 250,000 procedures and featured in more than 200 clinical articles.

“The ‘breakthrough device designation’ we received from the FDA is related to investigating a potential new use of the technology in the genicular arteries to reduce pain associated with osteoarthritis of the knee. This is referred to as genicular artery embolization, or GAE,” says Merit Medical Chief of Strategy and Innovation Officer Rob Fredericks. 

Interestingly, this embosphere technology is not solely used for knee osteoarthritis. In fact, it has been primarily on the market for entirely different indications. “Today, Embospheres are most commonly used to treat hypervascular tumors, including uterine fibroids, in the prostate arteries to relieve symptoms related to benign prostate hyperplasia (BPH) and to address arteriovenous malformations,” Fredericks explains. 

But how does this tiny “sphere” substance stop the blood flow? And isn’t it a bad thing for blood to stop flowing to a part of the body? 

“The technology consists of tiny, round particles about the size of a grain of sand, made of a substance called tris-acryl gelatin,” Fredericks says. “The particles are delivered into the body using narrow tubes called microcatheters. Physicians place the particles in a patient’s blood vessels to block blood flow to certain areas of the body, depending on the condition being treated.”

While Merit is looking to push the boundaries of the clinical care typically offered to patients suffering from symptomatic knee osteoarthritis, it does not need to shift the current technology to do so. “Our investigation of the use of Embospheres in new applications does not require physical modifications to the technology itself,” Fredericks says. “We see great opportunity to expand the use of the technology to applications such as GAE once the clinical evidence is robust and FDA and other regulatory agencies approve the use. 

Merit is leveraging an existing technology into this knee osteoarthritis space to fill a long-standing gap—proving that some of the most meaningful, impactful advances in clinical care are seen in the form of simple yet transformative solutions. 

Looking toward the horizon of future strategy and innovation coming from Merit’s incubator, “Our short to medium-term focus is conducting the clinical work to apply for regulatory approval to expand the use of Embospheres to GAE,” Fredericks predicts. “Timelines will be firmed up once the exact design of the study is agreed upon with FDA and begun. Beyond GAE, we have heard additional ideas from physicians for the use of the technology in other musculoskeletal applications. We may look deeper into expanding the indication for Embospheres to these areas at some point in the future.”