Small Molecules & Bone Grafting

Building a Better Bone Graft

Imagine a 55 year old woman who has been active her whole life and suddenly starts experiencing radiating leg pain. After 12 months of pain, she learns that it is due to arthritis in her lower back. Soon her vertebra has slipped and she is unable to walk even after exhausting non-operative treatment options. At this stage, she will need spinal surgery in order to stop the vertebra from slipping, which means a spinal fusion operation.

Human Spine

Over 250,000 spinal fusion procedures are performed in the U.S. every year. Some estimates have found that bone healing from such surgery has a rate of failure of up to 40%. Traditionally, bone has been harvested from the iliac crest and donated to the spine to promote bone fusion at the site of the slipped vertebra. This approach is painful, creates more opportunity for complications, and is very costly. In contrast to harvesting bone from other sites on the body, researchers have discovered a recombinant human protein that is capable of generating bone growth. Currently, there is only one approved biologic factor that is capable of regenerating bone growth, but it is very expensive and has limitations. Since being brought to market in 2002, it has achieved over $3 billion in sales. However, due to financial and regulatory reasons, this biologic bone growth factor is not available for the extensive population that needs it, and there are some remaining safety concerns with its use.

Since Scott Boden, MD, began his career as an orthopedic surgeon, he has focused on finding a better and cheaper bone grafting alternative for spinal fusion patients. As he describes, "I knew I could help patients beyond those I could touch with my own hands. Being a clinician makes me a better scientist, and being a scientist makes me a better clinician." In 1998, his laboratory identified a novel gene that activates the same pathway that promotes bone growth. Although a gene therapy approach ended up not being viable commercially for non-lethal diseases, in an attempt to understand the mechanism of action of that gene, Boden's research group uncovered new pathways and discovered small molecules that mimic the action of proteins responsible for new bone growth. Some of the molecules Boden's group identified are already approved by the FDA for other uses, which alleviates concerns regarding safety.

Scott Boden, MD

These compounds must be applied locally at the site of surgery at one point in time, which makes it a unique product from most drugs that are taken by mouth and circulate throughout the entire body. The vast patient population that would benefit from the compounds would make them an asset for any medical device company. The efficacy, uniqueness, and usefulness of these molecules has been well validated. They comprise the first small molecules capable of forming bone from scratch and go beyond simply promoting more rapid growth. These compounds are cheaper to manufacture compared to existing the protein-based bone-forming therapeutics, and simply require the proper scaffold for delivery and the funding for clinical trials. "We believe that small molecules that generate bone and have already been shown to be safe in humans is a very attractive potential product for companies in this arena" says Mark Coburn, licensing associate in the Office of Technology Transfer. The compounds Boden's group have developed can improve patient outcomes for most scenarios involving bone regeneration. They are applicable for the most challenging of bone healing environments and accelerating bone regeneration, which could have positive implications for a wide variety of patients even beyond those going through spinal fusion operations.

Techids: 10164, 11070, 11071, NCS.20, 19012