by Susan Hsiong, PhD

Biomimetics Therapeutics, Inc. (Franklin, TN), a company which develops drug-device combination products for orthopedic applications, recently announced positive results from its Canadian clinical study evaluating its GEM OS®1 Bone Graft for the open surgical treatment of foot and ankle fusions. The GEM OS®1 is a combination product comprised of a β-tricalcium phosphate matrix and recombinant-human platelet-derived growth factor (rhPDGF-BB) and is based on the same platform technology as their first product, GEM 21S®, only the second FDA recombinant protein approved product for orthopedic applications.

This product is similar to the market leading INFUSE® Bone Graft by Medtronic Sofamor Danek (the first FDA recombinant protein approved product (2002)) in that they are biomaterials releasing molecular therapeutics to drive local bone regeneration. The differences between the two products are the molecules (growth factor in this case) used to drive bone regeneration and the material used to guide where the bone regenerates:

*rhBMP-2 recombinant human bone morphogenetic protein 2

The main difference between the two growth factors is that the BMPs are the most widely studied, and have the capacity to initiate bone growth (BMP-2 being the most potent of these factors). PDGF, although important in bone healing and remodeling, is unlikely to be osteogenic itself. Bone graft substitutes (BGS) based on biomaterials and recombinant protein products may one day eliminate the need for an autologous (or autogeneous) bone grafts, currently the “gold standard”. Recombinant protein bone graft products are showing fusion rates similar or better than those achieved with autologous bone while having the additional advantage of reducing surgery complications and patient recovery times. The biologics/orthopedic market is profitable and growing, and there are an estimated half-million spinal fusion procedures and over a million foot and ankle fusion and corrective interventions performed annually in the United States

Biomimetics is taking the strategy of developing devices to address new markets based on the same proprietary technology platform (the material-growth factor combination). Once FDA approval is obtained for one product, approval of another product based on the same technology follows rather quickly. This allows the companies to expand into various markets (dental, spinal, foot and ankle, etc.) and generate revenue quickly. This is what Biomimetics did with their products: GEM 21S® was first approved for the dental market (2005) and GEM OS®1 is intended for foot and ankle fusions but both products are basically the same, perhaps with small differences in formulation or dosage of growth factor. Biomimetics recently sold its remaining dental business and rights for the GEM 21S® product in the dental area to Lupitold so it can focus on orthopedics. This deal brings in an infusion of cash to the company so it can further develop its product pipeline. It seems that Biomimetics is targeting more lucrative markets such as the sports injury area, however it is interesting that they are not going after spine fusion since this is such a large market. They may have decided that Infuse is too established a product to compete against, or are hoping for off-label use in that area.

Biomimetics next generation technology will allow for injection of the bone graft substitute directly into a fracture site without open surgery procedures. This minimally invasive approach makes for easier procedures for the surgeon and further reduces patient recovery time – creating marketing advantages and potentially opening up new indications. The marketing advantage comes from surgeon time savings. If a surgeon can perform the same procedure but it only takes 20% of the time, they will be more likely to use a product if it has the same efficacy. Also, the minimally invasive nature may allow procedures to be done outside of the OR, dramatically decreasing costs for the patients and hassle for the hospitals; a win-win situation that may allow for premium pricing. Biomimetics already has an injectable product in their pipeline (GEM OS®2).

Third generation technologies will likely focus on products which allow for more controlled delivery of the different molecular therapeutics, or products which deliver multiple molecules simultaneously and at different rates. However, these types of products will require an unprecedented understanding of the biology of healing, and the regulatory process for such multi-combination products is unclear. We will see how aggressively these truly convergent biological products are pursued by the regenerative medicine industry.