Hybrid molecule could have implications for osteonecrosis, fractures, osteoporosis and inflammatory arthritis.
The University of California, Davis, has reached a licensing agreement with Regenerative Arthritis and Bone Medicine (RABOME) for a class of drugs developed at the university that hold potential for treating diseases associated with bone loss and inflammatory arthritis.

The license, negotiated by the InnovationAccess team within the UC Davis Office of Research, provides the university–affiliated startup with rights to four families of patents and patent applications related to the novel composition of a hybrid molecule, known as LLP2A–alendronate, which has been found to effectively direct mesenchymal stem cells (MSCs) to induce bone regeneration in animal models. The compound works by guiding transplanted and endogenous MSCs to the surface of the bone where they differentiate into bone–forming cells, thereby increasing bone mass and strength. These cells are also immune–modulating, which helps to reduce inflammation at target sites.

The use of stem cells as therapeutic agents is a growing field, but directing stem cells to travel and adhere to the surface of bone for bone formation has been an elusive goal in regenerative medicine.

"There are many stem cells, even in elderly people, but they do not readily migrate to bone," said Wei Yao, co–inventor and associate professor of internal medicine at UC Davis. "Finding a molecule that attaches to stem cells and guides them to the targets we need provides a real breakthrough." Late last year, RABOME received approval from the U.S. Food and Drug Administration to begin phase I clinical trials to evaluate the safety of the drug in humans. The study sites are currently screening patients for enrollment.

"We are pursuing several indications for use, but our initial focus is in developing a treatment for osteonecrosis, a disease caused by reduced blood flow to bones," says Fred Tileston, president and chief executive officer RABOME, which is a California–based company. As many as 20,000 people per year in the United States develop osteonecrosis.

RABOME also plans to pursue other indications for use including fracture healing, osteoporosis and inflammatory arthritis.

"We are pleased that this very promising technology is being shepherded by Mr. Tileston, who is an experienced business leader and entrepreneur," said Dushyant Pathak, associate vice chancellor for Technology Management and Corporate Relations at UC Davis. "It is exciting to see the team’s progress in translating the discovery into commercial and societal impact."

The development of the novel therapy is the result of a successful research collaboration between two teams at UC Davis: a group of experts on bone health, led by Nancy Lane and Wei Yao from the UC Davis Center for Musculoskeletal Health, and a synergistic group of medicinal chemists led by Kit Lam and Ruiwu Liu from the Department of Biochemistry and Molecular Medicine.

"This research was a collaboration of stem cell biologists, biochemists, translational scientists, a bone biologist and clinicians," said Lane, endowed professor of medicine, rheumatology and aging research, and a principal investigator. "It was a truly fruitful team effort with remarkable results."

Lane received a Disease Team Therapy Development research grant in 2012 from the California Institute for Regenerative Medicine (CIRM) which, along with federal grants from the National Institutes of Health, supported the preclinical research. CIRM was established in 2004 via California Proposition 71 to fund stem cell research in attempt to accelerate and improve treatments for patients where current needs are unmet.