BioMimetic Therapeutics, Inc. has received orphan drug designation from the Food and Drug Administration (FDA) for its protein therapeutic, recombinant human platelet derived growth factor (rhPDGF-BB) for the treatment of Osteonecrosis of the Jaw (ONJ).

ONJ is a growing problem in the United States in patients receiving high doses of bisphosphonates for the treatment of severe osteoporosis and other diseases. Orphan drug status, designated to drugs that have the potential to treat rare diseases, provides an accelerated path to FDA approval and seven years of market exclusivity, a BioMimetic Therapeutics press release stated.

"ONJ lesions are often severely painful and debilitating open sores in the mouth for which there are currently no proven therapeutic treatments," said Dr. Samuel Lynch, president and CEO of BioMimetic Therapeutics. "Based on the ability of rhPDGF-BB to stimulate bone and tissue healing, we believe that rhPDGF-BB has the potential to help these patients. Thus, ONJ represents another potential to leverage our platform rhPDGF technology and be assured of market exclusivity in this indication."

Orphan drug designation was designed by the FDA to encourage the development of therapeutic products for clinical indications that affect fewer than 200,000 individuals within the United States. Drugs that receive orphan drug designation obtain seven years of marketing exclusivity from the date of drug approval as well as tax credits for clinical investigation costs, marketing application filing fee waivers and assistance from the FDA in the drug development process. Orphan drug designation does require a clinical trial to gain market approval authorization through the New Drug Application (NDA) process.

Osteonecrosis of the Jaw (ONJ) is also known by several other names, such as avascular or aseptic necrosis of the mandible/maxilla, bisphosphonate associated osteonecrosis of the jaw (BON), Jaw Rot, Dead Jaw disease or Bisphossy Jaw. The typical clinical presentation of ONJ includes pain, soft-tissue swelling and infection, loosening of teeth, drainage, and exposed bone. These symptoms may occur spontaneously, or more commonly, at the site of previous trauma, including tooth extraction. Patients may also present with feelings of numbness, heaviness and/or tingling of the jaw. The latter cases may be diagnosed after finding exposed bone in the jaw which doesn't heal following use of current therapies.

BioMimetic's product and product candidates use rhPDGF-BB (recombinant human Platelet-Derived Growth Factor), one of the principal wound healing stimulators in the body. The Company believes that rhPDGF-BB is well suited for various therapeutic applications due to its stimulation of a broad spectrum of cellular events critical for the initiation and progression of healing of musculoskeletal tissues including bones, tendons, ligaments and cartilage. rhPDGF-BB acts like a magnet to attract cells necessary for tissue healing through a process known as chemotaxis, while also stimulating an increase in the number of healing cells through a process known as mitogenesis, thereby expanding the number of cells available for the repair process. In addition, published in vivo and in vitro studies demonstrate that rhPDGF-BB may enhance processes important in new blood vessel formation at the wound site, a process called angiogenesis which is critical for wound healing.