Bone Biologics Bets on a More Selective Path to Spine Fusion

For most of the past two decades, the orthobiologics shelf has been defined by a familiar tradeoff. Surgeons could reach for ceramics and allografts that act as passive scaffolds, giving native bone a lattice to grow through, or they could reach for growth factors that drive bone formation more aggressively and accept the inflammation and off-target growth that can come with them. Burlington, Massachusetts-based Bone Biologics (NASDAQ: BBLG) is building its thesis on the idea that surgeons should not have to choose.

A More Targeted Mechanism

The company's lead candidate, NB1, pairs a recombinant human protein called NELL-1 with demineralized bone matrix. What makes NELL-1 interesting to CEO Jeff Frelick is not just that it promotes bone, but the targeted nature (mechanism of action) of bone promotion. “It only grows bone in the presence of bone,” Frelick said, describing NELL-1 as the mechanism that up regulates Runx2, the “master switch” for bone growth, only in osteoblasts. The protein occurs naturally in the body and is manufactured exogenously in biopharmaceutical reactors. If it does not encounter the bone-forming signal it is looking for, it clears the body in roughly a week. This was shown in Bone Biologics own pharmacokinetic studies that NELL-1 is 75% cleared in 24 hours and virtually 100% gone in 168 hours. 

That selectivity is the company's central safety argument, and Frelick frames it as a deliberate contrast to bone morphogenetic proteins. BMPs act much earlier, pushing mesenchymal stem cells down the osteogenic lineage whether or not they were headed there, which is a known source of inflammation and unwanted bone growth. NELL-1, in his description, waits for the right cellular address before doing anything at all.

A Deep Research Foundation

The technology emerged from university research, and the founding investigators produced an unusually deep body of evidence before the product reached a clinical roadmap. “There's 45+ peer-reviewed publications,” Frelick noted, a figure that exceeds what most companies at this stage can point to.

Frelick himself came to the company by an unusual route. After a biology degree, an MBA, and early years in the lab, he moved into medical device sales and management, then spent roughly 16 years on Wall Street as a sell-side analyst covering diagnostics, devices, and life science tools, with orthopedics among his focus areas. He joined Bone Biologics more than a decade ago because, having watched the space closely, he believed the technology was differentiated and could add value to the patients requiring bone graft material in spine fusion surgery.

Where the Program Stands

Today the company is enrolling a 30-patient pilot study in Australia. The trial enrolls patients with single-level degenerative disc disease and up to Grade 1 spondylolisthesis, across three arms: two dosed with the NB1 device-drug combination and a control arm using autograft. The primary performance endpoint is a composite consisting of bridging bone by XR, neurology, and Oswestry Disability Index score. Because the FDA has deemed this a PMA (pre-market approval) pathway for a device-drug combination, the pilot study is a required step before a larger U.S. pivotal trial. Frelick expects to report pilot results next year, file an IDE (investigational device exemption) to open the pivotal, and commence that larger study in late 2027 or early 2028 with a two-year follow-up.

Two Paths to Market

On commercialization, Frelick is keeping two options open. His distribution background leaves him prepared to launch independently through the dealer and agent network that dominates orthopedics, while major strategics are aware of the company and following its progress. For now, the operating rhythm is disciplined: advance the science, raise the necessary capital, repeat, yearly or so.

What keeps him going through a development arc measured in years is something more concrete than any endpoint. Frelick described calls from patients asking whether the product is available yet, including the hard healers, those who are obese, diabetic, smokers, or immunocompromised, who struggle to generate their own bone. An aging, active population only sharpens that demand. “The need for patient safety solutions, surgeon demand, and the growth of the spine fusion bone market support this,” he said.

For Frelick, that possibility is what turns a long, quarter-by-quarter march into a mission well worth the wait.