Bone or Cartilage Disease

Coding Dimension ID: 
279
Coding Dimension path name: 
Bone or Cartilage Disease

Tissue engineered cartilage from autologous, dermis-isolated, adult, stem (DIAS) cells

Funding Type: 
Early Translational III
Grant Number: 
TR3-05709
ICOC Funds Committed: 
$1 735 703
Disease Focus: 
Bone or Cartilage Disease
Stem Cell Use: 
Adult Stem Cell
oldStatus: 
Active
Public Abstract: 
This study addresses the cartilage defects resulting from injuries or from wear-and-tear that can eventually degenerate to osteoarthritis. This is a significant problem that impacts millions and costs in excess of $65B per annum in the US alone. Addressing this indication successfully holds potential for halting the progression of cartilage damage before it destroys the entire joint. We have shown that articular cartilage can be engineered with properties on par with native tissues using chondrocytes. Also, skin derived stem cells can be used to engineer new cartilage with significant mechanical integrity. Combining these findings, the new cellular therapy that this proposal seeks to develop is an autologous skin cell-derived combination product for articular cartilage repair. Three aims are proposed to advance this autologous, adult stem cell-based method: First, protocols shown to be efficacious in cartilage tissue engineering will be applied to skin-derived stem cells and show safety in the mouse model. Then, using a preclinical model, the desired biological response, toxicology, and durability will be verified. Finally, short-term safety and efficacy of cartilage repair will be examined in a different preclinical model. Successful completion of this DCF project will allow the start of preclinical studies in the sheep that demonstrate long-term safety and efficacy, as specified by the FDA.
Statement of Benefit to California: 
Arthritis is the leading cause of disability in the US, affecting over 46 million Americans. Of these, over 5 million Californians are affected by this debilitating disease, with roughly 3 million that are women and over 2 million that are men. Additionally, Californian youth is also included in the estimated 30 million children who participate in organized sports activities, whose yearly costs for injuries have been projected to be $1.8 billion. For young patients with knee injuries, 75% exhibit superficial (grade I–II) and 25% exhibit deep (grade III–IV) cartilage lesions. Young patients not only need to retain mobility for many years in life but also new, tissue-sparing techniques. This proposal seeks to develop an autologous, adult stem cell-based therapy that addresses grade II-IV cartilage lesions. The source of these cells will be the skin, using minimally invasive procedures. The development of such a therapy would expand the clinical options available to Californians. The assembled team of academics, orthopaedic surgeons, and veterinary surgeons are based in the [REDACTED]. The refinement of this research will not only benefit [REDACTED] in terms of increasing competitiveness for NIH funding, but it will also allow for Californian companies to license the technology and therefore benefit economically.
Progress Report: 
  • Cartilage degeneration resulting from injuries or wear-and-tear leads to osteoarthritis, which impacts millions and costs in excess of $65B per annum. No long-term solutions exist for cartilage degeneration, but cellular therapies hold promise toward replacing degenerated cartilage with healthy tissue. This Development Candidate Feasibility Award is a first step toward the overall goal of developing a cell-based cartilage repair therapy using stem cells derived from the skin. The therapy would consist of using a skin biopsy to harvest dermis-isolated, adult stem cells (DIAS cells), which will undergo processing to yield neocartilage. This neocartilage will then be implanted into the patient’s joint to restore or improve mobility.
  • Work during this progress report period has been divided into project preparation and scientific progress. Project preparation includes setting up facilities and approvals for work with human DIAS cells, identifying sources and acquiring human skin for DIAS cell isolation, and hiring and training personnel. Scientific progress includes a publication on co-cultures using stem cells, work on culturing larger numbers of cells using low oxygen tension, comparing stem cells from human skin of different anatomical locations, and gaining an understanding of the niches where skin stem cells may reside.
  • The project now has a consistent source of human dermis tissue from which stem cells can be isolated. This includes skin containing hair follicles and also skin without follicles. Spherical culture of human skin-derived stem cells has been performed. It was found that directing stem cells into cells that make cartilaginous matrix can be more efficacious if done under low oxygen tension. Since much of the prior work on directing stem cells from the skin to form neocartilage has been done using animal-derived stem cells, in the next project period neocartilage will be formed using human stem cells instead. Technologies developed using animal models can thus be translated toward human use.
  • Resulting from injuries or wear-and-tear that leads to osteoarthritis, cartilage degeneration is a problem that costs in excess of $65B per annum. Toward developing a long-term solution for this vexing problem, cellular therapies hold the promise of replacing degenerated cartilage with healthy tissue. This Development Candidate Feasibility Award is a first step toward the overall goal of developing a cell-based cartilage repair therapy using stem cells derived from the skin. The therapy would begin with a biopsy of the patient’s own skin to harvest dermis isolated, adult stem cells (DIAS cells), which will undergo processing to yield neocartilage. This neocartilage will then be implanted into the patient’s joint to restore or improve mobility.
  • During this progress report period, a major milestone has been completed. Previously, DIAS cells have been isolated from various animal models, including sheep, goat, and rabbit. Comparing animal skin and human skin showed notable differences, including morphology, response to enzymatic digestion, and the rate at which cells attach to tissue culture plastic. As a result, protocols that successfully yielded DIAS cells using animal models could not be directly applied to isolating DIAS cells from human skin. During the first six months of this reporting period, human DIAS cells were isolated and used to engineer neocartilage. Characterizing the human DIAS cell population showed that cells shared similar characteristics with stem and progenitor cells previously identified by other groups as originating from various niches of the skin. Neocartilage constructs formed using human DIAS cells were found to contain twice as much glycosaminoglycans and three times more collagen; these are cartilage extracellular matrix component important in imparting mechanical function to the tissue. Neocartilage constructs generated from human DIAS cells also contained five times higher compressive modulus and close to twice the tensile modulus of constructs generated using sheep DIAS cells. The completion of this important milestone allowed for progression to the next milestones of this award.
  • Milestone 2 of this award consists of examining safety of the engineered constructs in a small animal model. For the scaling-up of constructs to be used in an athymic mouse study, an experiment was conducted to finalize our protocol for generating human DIAS cell constructs, using what have been learned both from Milestone 1 and also from literature sources. Three methods for generating neocartilage constructs were examined. While the resultant constructs did not differ in mechanical properties, one method nonetheless yielded constructs of more uniform size and greater cell and glycosaminoglycan content.
  • For milestones 3 and 4, the originally proposed studies were to implant autologous neocartilage constructs in intermediate and large animal studies to examine efficacy of repair. To improve the translational potential of this project, CIRM has requested that neocartilage constructs of human origin be used instead. To ensure that the implanted constructs are not rejected, progress during this reporting period also includes identifying methods to immunosuppress intermediate and large animal models.
  • To summarize, progress during this reporting period includes the completion of Milestone 1 and work toward all other milestones of this award. Additionally, two papers have been published thus far to disseminate scientific findings to the public.

Gene Targeting to Endogenous Stem Cells for Segmental Bone Fracture Healing

Funding Type: 
Early Translational IV
Grant Number: 
TR4-06713
ICOC Funds Committed: 
$5 185 487
Disease Focus: 
Arthritis
Bone or Cartilage Disease
Stem Cell Use: 
Adult Stem Cell
Cell Line Generation: 
Adult Stem Cell
oldStatus: 
Active
Public Abstract: 
Segmental bone fractures are a complex medical condition. These injuries cause great suffering to patients, long-term hospitalization, repeated surgeries, loss of working days, and considerable costs to the health system. It is well known that bone grafts taken from the patient (autografts) are considered the gold-standard therapy for these bone defects. Yet these grafts are not always available, and their harvest often leads to prolonged pain. Allografts, are "dead" bone grafts, which are readily available from tissue banks, but have very low potential to induce bone repair. We have previously shown that stem cells from human bone marrow, engineered with a bone-forming gene, can lead to complete repair of segmental fractures. However, such an approach requires several steps, which could complicate and prolong the pathway to clinical use. An alternative approach would be to gene-modify stem cells that already reside in the fracture site. We were the first to show, in a rodent model, that a segmental bone defect can be completely repaired by recruitment stem cells to the defect site followed by direct gene delivery. In the proposed project we aim to further promote this approach to clinical studies. The project will include the development of a direct gene delivery technology, based on ultrasound. We will test the efficiency of the method in repairing large bone defects and its safety. If successful, we will be able to proceed to FDA approval towards first-in-human trials.
Statement of Benefit to California: 
Segmental bone defects are a complex medical problem that often requires bone grafting. Autografts are considered the gold standard for these defects, but their usage is limited by availability and donor-site morbidity and supply. Allografts are more available but often fail to integrate with the host bone. Thus there is an unmet need in the field of orthopedic medicine for novel therapies for segmental bone fractures. We propose to develop a novel approach for the treatment of such fractures without the need for a bone graft. Specifically, we will utilize ultrasound to deliver a bone-forming gene to stem cells that will be recruited to the defect site. As we have already shown, the gene would trigger the cells to regenerate the bone that had been lost due to trauma or cancer. If successful, this project could lead to the development of a simple treatment for massive bone loss. Such a treatment will benefit the citizens of California by reducing loss of workdays, duration of hospital stays, and operative costs, and by improving quality of life for Californians with complex segmental bone fractures.
Progress Report: 
  • Segmental bone fractures constitute a complex medical condition with no effective treatment. These injuries cause great suffering to patients, long-term hospitalization, repeated surgeries, loss of working days, and considerable costs to the health system. It is well known that autologous bone grafts (autografts) that are harvested from the patient, are considered the gold-standard therapy for these bone defects. Yet these grafts are not always available, and their harvest often leads to prolonged postoperative pain and comorbidity at the donor site. Bone allografts obtained from tissue banks are readily available, but lead to poor graft-host integration resulting in numerous failures. We have previously shown that mesenchymal stem cells (MSCs) engineered with a specific bone-forming gene can be used to achieve complete regeneration of segmental fractures in long bones. However, such an approach requires several steps—cell isolation, expansion, and engineering—which could complicate and prolong the regulatory pathway to clinical use. An alternative approach would be to gene-modify endogenous stem cells that reside within in the body. We were the first to show, in a rodent model, that a segmental bone defect can be completely repaired by recruitment of endogenous stem cells to the fracture site followed by direct gene delivery. In this research project we aimed to further promote this therapeutic approach to clinical studies. During the first year of the project we investigated the use of an ultrasound system to deliver genes to feature sites. Our results showed that we were able to deliver the genes to 40-50% of the cells residing in the fracture site. Moreover, 70-90% of the cells that received the genes were identified as stem cells, which are the target of the therapeutic approach. Our next goal would be to deliver bone-forming genes to stem cells in the fracture site in order to induce complete defect repair.

Multi-modal technology for non-destructive characterization of bioengineered tissues

Funding Type: 
Tools and Technologies III
Grant Number: 
RT3-07981
ICOC Funds Committed: 
$1 846 529
Disease Focus: 
Bone or Cartilage Disease
Stem Cell Use: 
Adult Stem Cell
Public Abstract: 
Stem cell technologies hold great promise for engineering replacement tissues for repairing functional loss from trauma or disease. Such therapies are particularly important for replacing bone and cartilage in the aging population to maintain an active quality of life. However, the application of stem cells to generate individualized implantable grafts suffers from patient-to-patient variability that is unpredictable and immeasurable without destructive techniques, representing a major bottleneck in translating stem cell technologies to the clinic and delivering a quality product. This process could be markedly improved by the availability of nondestructive, non- or minimally invasive methods to measure dynamic changes in tissue development, thereby reducing the quantity of tissue collection for sufficient cell numbers and cutting costs that do not directly benefit the patient. During tissue formation, cells deposit extracellular matrix molecules that possess a unique fluorescence signature, which can be detected by light, while matrix quantity, detectable by ultrasound, correlates with mechanical strength. We propose the development and application of a multi-modal imaging probe that uses light and sound to detect changes in engineered bone and cartilage, which reflect maturity and mechanical properties. The availability of this tool will advance the personalized medicine aspect of stem cell-based tissue formation while providing new insight into dynamic tissue development.
Statement of Benefit to California: 
The aging population of California, 20% of whom will be over 65 in 2025, will require functional replacement tissues to maintain their quality of life. The promise of using stem cells to generate individualized grafts suffers from donor variability that is unpredictable and immeasurable without destructive techniques. The development of a nondestructive, minimally invasive tool enabling the dynamic assessment of tissue maturation and remodeling would provide users unparalleled insight without destructive biopsies. Herein, we aim to develop a multi-modal imaging probe that uses light and sound to measure the maturity of stem cell-generated bone and cartilage by detecting unique signatures of extracellular matrix components and observing matrix deposition. After optimizing the probe for these tissues, we will characterize maturation of engineered tissues in vitro and after implantation. This tool will reduce the number of cells required to create tissues by eliminating destructive biopsies and provide an individualized tissue product to maximize clinical outcome, resulting in reduced healthcare costs. The technology will be invaluable to clinicians and biotechnology companies pursuing regenerative medicine in California. Finally, the exposure of trainees to new stem cell-related research may provide the greatest benefit to California by inspiring future scientists to pursue their research efforts within the state or develop therapies at California-based companies.

Treatment of osteoporosis with endogenous Mesenchymal stem cells

Funding Type: 
Disease Team Therapy Development - Research
Grant Number: 
DR2A-05302
ICOC Funds Committed: 
$19 999 867
Disease Focus: 
Bone or Cartilage Disease
Stem Cell Use: 
Adult Stem Cell
oldStatus: 
Active
Public Abstract: 
Although most individuals are aware that osteoporosis is disease of increased bone fragility that results from estrogen deficiency and aging, most are unaware of the high risk and cost of the disorder. It is estimated that close to 30% of the fractures that occur in the United States each year are due to osteoporosis (Schwartz & Kagan 2002). California, with one of the largest over-age-65 populations, is expected to double the fracture rate from 1995 to 2015 (Schwartz & Kagan 2002). Current treatment of osteoporosis is focused on anti-resorptive agents that prevent further bone loss. These agents and are effective in reducing new vertebral fractures but less effective for the prevention of hip fractures, and the duration of use of one anti-resorptive class, the bisphosphonates, is limited due to a concern about weakening of the cortical bone with longterm use. The only bone growing agent that is approved by FDA is the protein, hPTH 1-34, which requires two years of daily injections, is only approved by the FDA for one course of treatment, is only effective in about 60% of treated individuals for reduction of vertebral fractures, and has not been shown to be effective in reducing new hip fractures. This leaves an unmet medical need for an anabolic or agent that stimulates bone formation for millions of elderly Californians that suffer or will suffer from this disease. We have developed a small molecule, LLP2A-Ale that directs endogenous mesenchymal stem cells (MSCs), the cells that have the potential to grow bone tissue, to the bone surface to form new bone. We propose a development plan for this small molecule, LLP2A-Ale for the treatment of osteoporosis in both postmenopausal women and men. Yrs. 1-2: These 2 years will be spent with optimizing the manufacturing and packaging of the small molecule, obtaining information about the efficacy and toxicity in preclinical models, and preparing documents for an FDA meeting when the preclinical studies are completed to provide comment on the proposed Phase I clinical trials. Yrs. 3-4. We plan perform a Phase I study with two parts. Part I will study postmenopausal women with osteopenia and a fracture risk (3% for hip fracture and 20% for major nonvertebral fractures over the next 10 years). After the initial Phase I study in postmenopausal women we will perform Part 2 and study both postmenopausal women and men with similar inclusion and exclusion criteria. The primary endpoint of these studies will be change in biochemical markers of bone turnover (PINP, BSAP, osteocalcin), and secondary endpoints will be bone mineral density of the lumbar spine measured by DXA and trabecular bone volume measured by QCT. The Phase I trials will also include required pharmacokinetic and pharmacodynamic measures to obtain information about the action of this small molecule and to inform us for Phase II clinical studies in the future.
Statement of Benefit to California: 
Osteoporosis is a disease of the elderly that results from a process of age related bone loss that renders the bone fragile. Current osteoporosis treatments have relatively good efficacy in reducing incident fractures. However these agents (anti-resorptive agents or the anabolic agent rhPTH (1-34) only reduce the risk of vertebral fractures about 60%, and hip fractures only 40%, and these agents require years of treatment to be effective. The goal of this project is to increase bone homing of the endogenous MSCs with a small molecule (LLP2A-Ale) to form new bone as a novel treatment for osteoporosis that could cure osteoporosis with only 3-4 injections by mobilizing the endogenous MSCs to build bone. Our molecule would be highly competitive in this market as the efficacy of increasing bone mass and bone strength would be high and the risks in a very acceptable range. The market potential for bone tissue regeneration is large as it is estimated that close to 1/3 of fractures that occur in the US each year are due to osteoporosis (Schwartz & Kagan (2002). California, with one of the largest over-age-65 populations, is expected to double the fracture rate from 1995 to 2015 (Schwartz & Kagan 2002). One study places the cost per year in osteoporotic fractures at 2.4 billion dollars (Schwartz & Kagan 2002), establishing it as one of the highest health care costs for older individuals. The prevalence of osteoporosis is projected to increase with increasing lifespan globally both from age related bone loss and from secondary causes of bone loss including inflammatory diseases and cancer. The market potential for bone tissue regeneration is large, an estimated 2 million fractures and $19 billion in costs annually. By 2025, experts predict that osteoporosis will be responsible for approximately 3 million fractures and $25.3 billion in costs each year (publication from National Osteoporosis Foundation). The osteoporotic patients spend about $10 a month for the generic version of Fosamax, at the lower end, to about $80 a month for brand-name Fosamax or Actonel to $900 or more a month for Forteo (rhPTH (1-34). Therefore, once validated in osteoporosis patients, this form of tissue regeneration would be effective in patients with primary osteoporosis, in patients with secondary osteoporosis due to long term glucocorticoid treatment or after chemotherapy in both men and women and to augment peak bone mass in children in whom current osteoporosis medications are contraindicated, in individuals who have had radiation to their skeletons in whom rhPTH (1-34) is contraindicated and to augment fracture healing in the elderly. Our agent would have the potential to save the State of California millions of dollars in health care and would allow these osteoporotic individuals to live longer and be independent longer.
Progress Report: 
  • One of the early goals for this project is the successful development and clinical grade manufacturing of the drug LLP2A-Alendronate (LLP2A-Ale). We are pleased that we now have a robust stability indicating method that has been transferred for use in drug product development. We are currently working with our collaborators on stability maintenance and monitoring of the compound.
  • At the annual CIRM advisory committee review in late October 2013, the reviewers liked the "hybrid" compound. However, they also felt that the project would benefit from additional preclinical studies to compare two treatments for osteoporosis that are currently available, alendronate and PTH. Therefore, based on the advisory committee's comments, we will conduct further studies that confirm and support our original hypotheses. We are looking forward to beginning clinical trials soon after those studies are completed.
  • This past year, on the advice of CDAP, we completed the recommended additional proof of concept studies with LLP2A-Ale for age related osteoporosis and other indications. These new studies have demonstrated that LLP2A-Ale can also be effective in fracture healing and osteonecrosis. In addition, we completed the requested drug stability testing of LLP2A-Ale.
  • At this time we are awaiting decision by CIRM/CDAP regarding continuation of our Disease Team project for the use of LLP2A-Ale for the treatment of bone diseases.

Increasing the endogenous mesenchymal stem cells to the bone surface to treat osteoporosis

Funding Type: 
Disease Team Therapy Planning I
Grant Number: 
DR2-05302
ICOC Funds Committed: 
$110 000
Disease Focus: 
Bone or Cartilage Disease
oldStatus: 
Closed
Public Abstract: 
Although most individuals are aware that osteoporosis is disease of increased bone fragility that results from estrogen deficiency and aging, most are unaware of the high risk and cost of the disorder. It is estimated that close to 30% of the fractures that occur in the United States each year are due to osteoporosis (Schwartz & Kagan (2002). California, with one of the largest over-age-65 populations, is expected to double the fracture rate from 1995 to 2015 (Schwartz & Kagan 2002). One study places the cost per year in osteoporotic fractures at 2.4 billion dollars (Schwartz & Kagan 2002), establishing it as one of the highest health care costs for older individuals. The prevalence of osteoporosis is projected to increase with increasing lifespan globally both from age related bone loss and from secondary causes of bone loss including inflammatory diseases and cancer. In additional, medications used for the treatment of cancer and inflammatory diseases can also induce bone loss. Current treatment of osteoporosis is focused on agents that prevent further bone loss such as the bisphosphonates or selective estrogen modulators. The only bone growing agent that is approved by FDA is the protein, hPTH 1-34, which requires two years of daily injections and is only effective in about 60% of treated individuals. We have developed a small molecule, LLP2A-Alendronate that augments the homing of endogenous mesenchymal stem cells (MSCs), the cells that have the potential to grow bone tissue, to the bone surface and form new bone. Therefore, we plan to file IND in the next sin months and we will perform two clinical trials to test its safety and efficacy in two clinical trials in the next fours years. Yrs. 1-2: Phase I clinical trial. To determine if LLP2A-Ale is safe when used in patients with osteoporosis. After this phase I study, our research group will decide on two or three doses of LLP2A-Ale and two dosing regimens and will perform a phase II clinical trial. Yrs. 3-4: Our phase II clinical trials will evaluate the efficacy of LLP2A-Ale in patients with osteoporosis The primary endpoint will be bone mineral density measured by DEXA of the lumbar spine and hip and biochemical markers of bone turnover, also calciotrophic hormones of bone metabolism (Vitamin D, FGF23, Sclerostin, IGF-1,and sclerostin,etc). Secondary clinical study endpoints will include a detailed assessment of the quantity of new bone formed and its distribution throughout the skeleton with XtremeCT, a new high-resolution 3 dimensional bone scan that allows regular follow-up measurements with software that automatically matches cortical and trabecular bone regions (SCANCO Medical microCT Systems) at 3 month intervals and bone biopsies performed at the iliac crest after treatment is completed. All the patients in the trials will be followed at 3 month intervals for 2 years.
Statement of Benefit to California: 
Osteoporosis is a disease of the elderly that results from a process of age related bone loss that renders the bone fragile such that it breaks with very little force. Current osteoporosis treatments have relatively good efficacy in improving bone strength and reducing incident fractures, however these agents ( anti-resorptive agents or the anabolic agent rhPTH (1-34) only reduce the risk of hip fractures by 40%, and require years of treatment to be effective. The goal of this project is to increase bone homing of the endogenous MSCs with a novel compound to form new bone as a novel treatment for osteoporosis. A compound that could cure osteoporosis with only 3-4 injections of an agent that mobilized MSCs to build bone would be highly competitive in this market as the efficacy of increasing bone mass and bone strength would be high and the risks in a very acceptable range. This agent would be effective in patients with primary osteoporosis defined by very low bone mass or low trauma fractures, in patients with secondary osteoporosis due to long term glucocorticoid treatment or after chemotherapy in both men and women and to augment peak bone mass in adolescents. The market potential for bone tissue regeneration is large, an estimated two million fractures and $19 billion in costs annually. By 2025, experts predict that osteoporosis will be responsible for approximately three million fractures and $25.3 billion in costs each year (publication from National Osteoporosis Function). The osteoporotic patients spend about $10 a month for the generic version of Fosamax, at the lower end, to about $80 a month for brand-name Fosamax or Actonel to $900 or more a month for Forteo (huPTH (1-34).A compound that could cure osteoporosis with only 3-4 injections of an agent that mobilized MSCs to build bone would be highly competitive in this market as the efficacy of increasing bone mass and bone strength would be high and the risks in a very acceptable range. Once validated in osteoporosis patients, this form of tissue regeneration will be useful for children in whom current osteoporosis medications is contraindicated, individuals who have had radiation to their skeletons, and to augment fracture healing in the elderly. The market potential for bone tissue regeneration is large as it is estimated that close to 1/3 of fractures that occur in the US each year are due to osteoporosis (Schwartz & Kagan (2002). California, with one of the largest over-age-65 populations, is expected to double the fracture rate from 1995 to 2015 (Schwartz & Kagan 2002). One study places the cost per year in osteoporotic fractures at 2.4 billion dollars (Schwartz & Kagan 2002), establishing it as one of the highest health care costs for older individuals. The prevalence of osteoporosis is projected to increase with increasing lifespan globally both from age related bone loss and from secondary causes of bone loss including inflammatory diseases and cancer.
Progress Report: 
  • The purpose of our Disease Team planning grant was to develop a solid Clinical development program for our compound, LLP2A- Ale that directs mesenchymal stem cells to the bone marrow and stimulates new bone formation.
  • We published our scientific findings in the Journal Nature Medicine (2012 March issue). Our research team developed a clinical development program that included producing compound, performing toxicity studies, and a clinical development plan for a Phase I study. We also submitted an IND for the FDA, the FDA responded to our clinical development program and questions we raised, and we had a teleconference with the FDA CDER group on January 31st, 2012.
  • We have obtained sufficient information from the FDA on our IND to begin producing our compound for toxicity studies. In addition, we participated in a Stem Cell Awareness Public Forum at UC Davis in which we displayed our work with the mesenchymal stem cells to build new bone.

Clinical Development of an osteoinductive therapy to prevent osteoporosis-related fractures

Funding Type: 
Disease Team Therapy Planning I
Grant Number: 
DR2-05368
Investigator: 
ICOC Funds Committed: 
$99 110
Disease Focus: 
Bone or Cartilage Disease
oldStatus: 
Closed
Public Abstract: 
There are over 1.5 million osteoporotic fractures annually in the USA alone, at a cost of approximately $15 billion each year. The majority of these fractures occur in the spine, followed by the hip and wrist. Incidence varies according to age; vertebral fracture rates increase rapidly by the sixth decade of life, whereas the risk of hip fracture rises markedly by the eighth decade and beyond. Current treatment is focused on prevention using osteoclast inhibitors, hormone therapy, diet and exercise. When a fracture occurs current therapies involve injection of cement into the vertebral body and/or open surgery with implants. Unfortunately, these procedures do not regenerate bone tissue, often fail and incur risks of leakage and emboli. The clinical and economic impact associated with these fractures is substantial. Following a fragility fracture, significant pain, disability, and deformity can ensue. If fracture union is not achieved, the patient may suffer long-term disability. This is exacerbated because there is a five-fold increase in the risk for sustaining a subsequent vertebral fracture and the odds that a neighboring vertebrae will fail within one year is >20%. We propose to add a noninvasive anabolic option to the treatment and prevention of osteoporotic fractures. This therapy utilizes a novel small molecule Wnt pathway activator that drives the endogenous stem cells in the bone compartment to differentiate into bone forming osteoblasts thereby increasing bone mass and reducing the risk of fracture. This therapy will be administered 1-2X/year by injection, eliminating the concerns over patient compliance and revolutionizing the treatment of vertebral and hip fractures in patients suffering from osteoporosis.
Statement of Benefit to California: 
There are over 25 million osteoporosis patients in the US alone, leading to 1.5 million osteoporotic fractures annually at a cost of approximately $17 billion per year. The lifetime incidence of fragility fractures secondary to osteoporosis in females over fifty years of age is approximately 1 in 2, and in males over the age of fifty, is 1 in 4. Osteoporosis-related vertebral compression fractures are the most common fragility fractures in the United States, accounting for more than 79% of the total. Approximately 70,000 OVCFs result in hospitalization each year with an average hospital stay per patient of 8 days. Current treatment is focused on prevention using osteoclast inhibitors, hormone therapy, diet and exercise. When a fracture occurs, current therapies involve injection of cement into the vertebral body and/or open surgery with implants. Unfortunately, these procedures do not regenerate bone tissue, often fail, incur risks of leakage and emboli, and suffer significant side effects. The clinical and economic impact associated with these fractures is substantial. Following a fragility fracture, significant pain, disability, and deformity can ensue. If fracture union is not achieved, the patient may suffer long-term disability. This is exacerbated because there is a five-fold increase in the risk for sustaining a subsequent vertebral fracture after the first fracture, and the odds that an adjacent vertebrae will fail within one year is >20%. We propose to add a noninvasive anabolic option to the treatment and prevention of osteoporotic fractures, with minimal to no side effects or systemic safety concerns. This therapy utilizes a novel small molecule Wnt pathway activator that drives the endogenous stem cells in the bone compartment to differentiate into bone forming cells, thereby increasing bone mass and reducing the risk of fracture. This therapy will be administered 1-4 times per year by injection, eliminating the concerns over patient compliance and revolutionizing the treatment of vertebral and hip fractures in patients suffering from osteoporosis. This will benefit the citizens of California by reducing hospitalization periods, operative costs and loss of workdays, and by improving quality of life for Californians with osteoporosis that are at risk for OVCFs.
Progress Report: 
  • This project is working to advance a first-in-class, small molecule Wnt pathway activator through IND-enabling and Phase I/II clinical studies for treatment of osteoporotic hip fractures. During this reporting period, quotes were solicited from drug manufacturing companies for the manufacture of the drug compound, a manufacturer was selected and the drug is presently in the GMP manufacturing process. In addition, international thought leaders were identified to act as clinical consultants and with their input the outline of a Phase I/II clinical trial plan was drafted and submitted to the FDA for comment. Beyond that, a pre-IND briefing document was prepared that described the clinical product’s known pharmacology, pharmacokinetic, toxicology and chemical characteristics. After preparing and submitting the clinical plan outline and pre-IND briefing document to the FDA, the team had a successful pre-IND meeting on January 30, 2012. IND filing is proposed for the first half of 2013. Currently, quotes have been requested for contract research organizations (CROs) who offer appropriate preclinical fracture model studies and a decision on the most suitable vendor for the study will be determined shortly.
  • In addition, the CIRM disease team application detailing known properties of the drug, along with a 4 year development plan and associated budget was drafted and completed during the reporting period.

Genetically Engineered Mesenchymal Stem Cells for the Treatment of Vertebral Compression Fractures.

Funding Type: 
Disease Team Therapy Planning I
Grant Number: 
DR2-05288
ICOC Funds Committed: 
$109 743
Disease Focus: 
Bone or Cartilage Disease
oldStatus: 
Closed
Public Abstract: 
Osteoporosis is an unsolved and highly prevalent health care problem: 10 million Americans suffer from the disease, and an additional 34 million have low bone mass. Roughly half of all women and a fourth of all men older than 50 years will sustain an osteoporosis-related fracture at some time in their lives, and when such a fracture occurs, the chances of death within 12 months are about 1 in 5. Osteoporotic fractures can take several forms, but VCFs (vertebral compression fractures) occur at a rate of 700,000 per year—twice the rate of hip fractures. The economic burden of osteoporotic fractures is tremendous. In 2001, there were approximately 1.5 million osteoporosis-related fractures in the US at a cost of $17 billion, or approximately $47 million per day. Currently, treatment is focused primarily on prevention. When fractures occur in patients with osteoporosis, treatment options are limited because open surgery with implants often fails. Recently, new therapies involving injection of cement into the vertebral body were developed. Unfortunately, these procedures do not regenerate bone tissue, but do incur risks of leakage and emboli. Moreover,recent publications in leading scientific journal question the effectiveness of those procedures. Hence, we need new biological treatment that will promote repair of such fractures in a safe and efficient manner. We propose to develop a therapy that exploits MSCs (mesenchymal stem cells) that are genetically engineered to express a bone-inducing gene, bone morphogenetic protein-2 (BMP-2). Those cells have been shown to induce bone formation and fracture repair in numerous studies in animal models. Specifically, we intend to use allogeneic ("off the shelf") human MSCs. These cells will be genetically engineered with a BMP-2 gene using a technology based on short electric pulses. BMP-2 engineered MSCs have an advantage in bone repair since they become bone cells by themselves and recruit additional cells from the environment. This synergistic effect leads to accelerated and robust bone formation, which could be an attractive therapy for a variety of clinical conditions involving bone lose. An image-guided injection of BMP-2 engineered MSCs to a fractured vertebra could be an attractive treatment that would lead to rapid fracture repair and shortening of hospitalization time. We propose to use off-the-shelf MSCs that do not require the patient to undergo additional medical procedure such as bone marrow aspiration. In addition, the use of allogeneic cells is not limited by cell number, as could be the case for autologous cells, that are taken from the patient. If successful, this therapeutic strategy could revolutionize the treatment in osteoporsis patients, offering a minimal-invasive, biological solution. We plan to analyze aspects of efficiency and safety of the proposed therapy in a pre-clinical model, that will enable us to submit an approvable IND to the FDA by the end of the 4-year project.
Statement of Benefit to California: 
Approximately 10 million people in the United States are diagnosed as osteoporotic, while an additional 34 million are classified as having low bone mass. The lifetime incidence of fragility fractures secondary to osteoporosis in females over fifty years of age is approximately 1 in 2, and in males over the age of fifty, is 1 in 4. Vertebral compression fractures (VCFs) are the most common fragility fractures in the United States, accounting for approximately 700,000 injuries per year, twice the rate of hip fractures. Approximately 70,000 VCFs result in hospitalization each year with an average hospital stay per patient of 8 days. Fragility fractures due to osteoporosis also place a severe financial strain upon the health care industry. Estimates show there were approximately 1.5 million osteoporosis-related fractures in the United States in 2001, the care of which cost about $17 billion. Moreover, as the number of individuals over the age of fifty continues to increase, costs are predicted to rise to an estimated $60 billion a year by the year 2030. VCFs have previously received limited attention from the spine care community. This oversight may be a result of the perception that VCFs are benign, self-limited problems or that treatment options are limited. However, it has become clear that VCFs are associated with significant physiologic and functional impairment, even in patients not presenting for medical evaluation at the time of fracture. Current treatment of osteoporotic patients is mostly focused on prevention of VCFs. There are a few options of treatment when VCFs actually occur. Since open surgery involves morbidity and implant failure in the osteoporotic patient population, nonoperative management, including medications and bracing, is usually recommended for the vast majority of patients. Unfortunately, large numbers of patients report intractable pain and inability to return to activities. Currently there is no efficient biological solution for the treatment of VCFs. The proposed study will further develop a biological therapeutic solution that will accelerate repair of VCFs. The treatment will rely upon adult stem cell that are genetically engineered to overexpress an osteogenic gene, BMP-2, using a non-viral technique that is currently in clinical trials. It will also involve an injection of the cells into the fracture site, instead of a percutaneous injection of a polymer, which does not restore lost bone tissue. Data generated form this study could potentially revolutionize the treatment of vertebral fractures and other complex fractures in patients suffering from osteoporosis, and so benefit the citizens of California by reducing hospitalization periods, operative costs and loss of workdays, and by improving quality of life for Californians with osteoporosis that are at risk for VCFs.
Progress Report: 
  • Approximately 10 million people in the United States are diagnosed as osteoporotic, while an additional 34 million are classified as having low bone mass. The lifetime incidence of fragility fractures secondary to osteoporosis in females over the age of fifty years of age is approximately 1 in 2, and in males over the age of fifty, is 1 in 4. Vertebral compression fractures (VCFs) are the most common fragility fractures in the United States, accounting for approximately 700,000 injuries per year, twice the rate of hip fractures. Approximately 70,000 VCFs result in hospitalization each year with an average hospital stay per patient of 8 days. There are limited options of treatment when VCFs occur. New, non-biological, methods have been developed to regain the biomechanical properties of a fractured vertebral body. These methods include the minimally invasive procedures of vertebroplasty and balloon tamp reduction. Both procedures involve injection of synthetic nonbiological material that does not resorb and instead remains a permanent foreign-body fixture in the spine. Ultimately, a biological solution that would promote rapid fracture healing and stimulate normal bone production would be the best for osteoporotic patients with vertebral column injuries. Our goal is to develop a novel therapy for VCFs, which will be based on adult stem cells, isolated from bone marrow samples. These cells will be "triggered" to form bone by the activation of a specific gene and then injected into the fractured vertebra leading to fast fracture repair. The funding from the planning award allowed us to establish a highly experienced team, from the academy and industry, that would be able to bring the proposed therapy to clinical use. In addition, we assembled a comprehensive development plan that described in detail the studies and steps required to obtain an approval from the FDA in order to begin clinical trials. Furthermore, we have negotiated and obtained commitment from several biotech companies, which will provide the necessary materials and facilities to perform the studies described in the development plan. Our proposal for a Disease Team Therapy Development Award was submitted in January 2012. If awarded, we will be beginning the pre - clinical studies in August 2012.

Cartilage Regeneration by the Chondrogenic Small Molecule PRO1 during Osteoarthritis

Funding Type: 
Early Translational II
Grant Number: 
TR2-01829
ICOC Funds Committed: 
$6 792 660
Disease Focus: 
Arthritis
Bone or Cartilage Disease
Stem Cell Use: 
Adult Stem Cell
Cell Line Generation: 
Other
oldStatus: 
Active
Public Abstract: 
The ability to direct the differentiation of resident mesenchymal stem cells (MSCs) towards the cartilage lineage offers considerable promise for the regeneration of articular cartilage after traumatic joint injury or age-related osteoarthritis (OA). MSCs can be stimulated in vitro to form new functional cartilage. In the OA-affected joint, the repair is insufficient, leaving a damaged matrix, suggesting that key factors are missing to properly direct the regenerative process. Molecules that activate the chondrogenic potential of cartilage stem cells may potentially prevent further cartilage destruction and stimulate repair of cartilage lesions. Currently there are no disease-modifying therapeutics available for the 40 million Americans suffering from OA. Therapeutic options are limited to oral and intra-articularly injected pain medications and joint replacement surgery. The primary objective of this project is to develop a non-invasive, therapeutic for the regeneration of cartilage in OA. This new therapy will target the resident MSCs in the joint, stimulate production of new cartilage matrix, promote repair and thus limit additional joint damage and improve joint pain and function. To provide a proof-of-concept for our strategy, a cell-based screen of a diverse small molecule library led to compounds capable of enhancing the formation of articular cartilage (chondrogenesis) from MSCs in vitro. In secondary assays, molecules were assessed for protection of the existing cartilage against induced tissue damage. Through these approaches, the lead low molecular weight small molecule PRO1 was identified which promotes cartilage differentiation and protects cartilage from damage. PRO1 reproducibly demonstrated in vivo efficacy in two animal models of OA (surgical and enzyme-induced). OA-associated pain was reduced and the architecture of the cartilage was restored. PRO1 therefore appears to activate the regenerative potential of the resident cartilage stem cells.
Statement of Benefit to California: 
Osteoarthritis (OA) is the most prevalent musculoskeletal disease and globally the 4th leading cause of Years Lost to Disease (YLD). OA affects over 40 million Americans and the magnitude of the problem is predicted to increase even further with the obesity epidemic and aging of the baby boomer generation. It is estimated that 80% of the population will have radiographic evidence of OA by age 65 years. The annual economic impact of arthritis in the U.S. is estimated at over $100 billion, representing more than 2% of the gross domestic product. OA accounts for 25% of visits to primary care physicians. In 2004 OA patients received 650,000 knee and hip replacements at a cost of $26 billion. Without change in treatment options 1.8 million joint replacements will be performed in 2015. OA is a painful, degenerative type of arthritis; physical activity can become difficult or impossible. Some patients with osteoarthritis are forced to stop working because their condition becomes so limiting. OA can interfere with a patient's ability to even perform routine daily activities, resulting in a decrease in quality of life. The goals of osteoarthritis treatment are to relieve pain and other symptoms, preserve or improve joint function, and reduce physical disability. Current therapeutic options are limited to pain medications and joint replacement for patients with advanced disease. No disease-modifying OA drugs are approved for clinical use. OA is thus a major unmet medical need with a huge clinical and socioeconomic impact and a complete absence of effective therapies. Clearly the development of a new therapeutic that is both symptom and disease modifying would have a significant impact on the well-being of Californians and reduce the negative economic impact on the state resulting from this highly prevalent disease.
Progress Report: 
  • We have carried out a structure-activity relationship study to identify highly potent analogues of kartogenin with chondrogenic and chondroprotective activities. Over 150 analogues were synthesized with structurally diverse elements and assessed for chondrogenic activity (ability to induce mesenchymal stem cells to differentiate into cartilage producing chondrocytes) on human and rodent mesenchymal stem cells. A number of highly potent lead compounds were identified which will next be assessed in chondroprotective assays, cell-based selectively and toxicity assays, pharmacokinetic assays and in vivo rodent efficacy models. At the same time a number of assays were developed and used to assess the chondrocyte protective effects, joint retention, and proliferative activity on human chondrocytes of the parent compound, kartogenin. Kartogenin was found to: (1) have long term human and rodent chondrogenic activity; (2) possess chondroprotective activity in bovine chondrocytes (i.e., protects against degradative activities in the joint); (3) minimally induce chondrocytes proliferation (an undesired activity that could lead to fibrotic and immune responses); (4) have good joint retention (compound retained in the intra-articular space at the site of action); and (5) is subject to rapid systemic clearance (a desirable property to minimize systemic adverse effects).
  • We also identified the mechanism by which the compound functions. In contrast to other drugs in development for osteoarthritis, kartogenin does not target extracellular enzymes involved in joint cartilage degradation. Rather it appears to act directly on an endogenous stem cell population and induce chondrocyte formation. The molecule binds selectively to an intracellular protein filamin A, a protein involved in regulating the cell’s cytoskeletal network (structural elements inside the cell). Rather than modulating the interaction of filamin A with other structural proteins, kartogenin blocks its interaction with the protein CBFβ (core binding factor β subunit, a subunit of a transcription complex with the runt-related transcription factor (RUNX) family). The result is an increase in CBFβ levels in the nucleus where it binds and activates transcription of RUNX dependent genes. In particular CBFβ activates RUNX1 dependent transcription of genes that play key roles in chondrogenesis. Thus this molecule acts by a novel mechanism directly and selectively on gene transcription to induce the selective differentiation of mesenchymal stem cells to chondrocytes. Importantly molecules that act by this method should complement the activity of drugs in clinical trials aimed at blocking degradative enzymes.
  • We have made excellent progress toward the identification of a preclinical candidate for the treatment of osteoarthritis. A large structure-activity relationship study was carried out with the chemical synthesis of over 250 analogues of the original lead compound. We have identified molecules with improved activity in cell culture and in relevant preclinical in vivo models. Based on these efforts we are synthesizing a final series of molecules which we will profile with respect to in vitro and in vivo chondrogenesis activity, pharmacokinetics and safety. We expect to choose the final preclinical candidate from this series in the third year of the grant.
  • Osteoarthritis (OA) is the most prevalent musculoskeletal disease affecting about 27 million people in the United States, and is the leading cause of chronic disability in the United States. Current therapeutic options are limited to pain or symptom-modifying drugs and joint replacement surgery; no disease-modifying drugs are approved for clinical use. OA is characterized by progressive degeneration of the articular cartilage, resulting from abnormal activation, differentiation and death of cartilage cells. A unique and unexplored therapeutic opportunity exists to induce somatic stem cells to regenerate the damaged tissue and reverse the chronic destructive process. Because limited joints are affected in most OA patients, intra-articular (IA) drug injection is an attractive treatment approach that allows high local drug concentration with limited systemic exposure. Targeting resident stem cells pharmacologically also avoids the risks and costs associated with cell-based approaches.
  • Cartilage contains resident mesenchymal stem cells (MSCs) that can be differentiated in vitro to form chondrocytes. This observation suggests that intra-articular injection of a small molecule that promotes chondrogenesis in vivo will preserve and regenerate cartilage in OA-affected joints. Using an image-based screen, we identified a drug-like small molecule, kartogenin (KGN), that promotes efficient and selective chondrocyte differentiation from MSCs in vitro. Intra-articular injection of KGN also shows beneficial effects in surgery-induced acute and enzyme-induced chronic cartilage injury models in rodents, as well as positive effects in incapacitance pain models. This project is aimed at the development of new lead compounds with improved biological activity, the demonstration of efficacy of the lead compounds in rodent and dog OA models and the elucidation of the cellular mechanisms underlying the cartilage regeneration activities of KGN and its analogs.
  • Through medicinal chemistry efforts, we have designed and synthesized over 400 analogs of KGN. Using cell culture based assays, we assessed the chondrocyte differentiation activity of these analogs and identified 17 compounds exhibiting improved potency compared to KGN (EC50 < 100 nM). These compounds showed no obvious cytotoxicity at high concentrations (100 μM) when incubated with a variety of cells present in the joints including MSCs, chondrocytes, osteoblasts and synoviocytes. Up to date, we have assessed the efficacy of 7 compounds using a rat OA model (medial meniscal tear). Two of the tested compounds showed significantly improved cartilage repair at the end of the study. At the same time, no adverse effects, such as body weight loss, pain or impaired motor functions, were observed in any compound treated animals. We are currently studying the effects of another 10 analogs using the same OA model, which is expected to conclude within two to three months. Next, we will assess the efficacy of active compounds in a canine OA model (partial meniscectomy using beagles). Furthermore, full rodent pharmacokinetics and non-GLP toxicology studies will be performed for the lead compounds.
  • To study the underlying mechanisms of KGN induced chondrogenesis, we designed and synthesized an affinity probe with biological activities comparable to that of KGN. Through affinity-based methods, we identified protein filamin A (FLNA) as the target of KGN. In MSCs, KGN binds to FLNA and disrupts its interaction with core binding factor β (CBFβ), which leads to the nuclear translocalization of CBFβ, subsequent activation of the RUNX1-CBFβ transcription program and, as a result, chondrocyte differentiation. This mechanism has been confirmed using cell biological methods including RNAi mediated gene silencing and cDNA overexpression of relevant genes such as FLNA, CBFβ and RUNX1. These studies have been published in the journal Science.
  • We have demonstrated efficacy in preclinical in vivo models of a potential drug candidate for the treatment of osteoarthritis. The small molecule functions by selectively differentiating meschenchymal stem cells to chondrocytes to repair damaged cartilage .

Harnessing native fat-residing stem cells for bone regeneration

Funding Type: 
Early Translational II
Grant Number: 
TR2-01821
ICOC Funds Committed: 
$5 391 560
Disease Focus: 
Bone or Cartilage Disease
Stem Cell Use: 
Adult Stem Cell
Cell Line Generation: 
Other
oldStatus: 
Active
Public Abstract: 
Like most tissues of the body, bone possesses a natural regenerative system aimed at restoring cells and tissues lost to natural cell aging, disease or injury. These natural regenerative systems are complex combinations of cell growth factors and support structures that guide and control the development of specialized bone stem cells. However, the regeneration process may still fail, for multiple reasons. For instance, the degree of skeletal injury may be so great that it overwhelms the natural regenerative capacity. Alternatively, the natural regenerative capacity may be defective; this is exemplified by osteoporosis, a frequent condition affecting post-menopausal females and elderly males and females. Osteoporotic individuals have severe declines in stem cell numbers (10-fold decrease from age 30 to 80) and stem cell function (tendency of stem cells to turn into fat rather than bone cells with age), leading to bone loss and “fragility fractures” that typically would not occur in persons with normal stem cell number and function. Thus, there is a tremendous need for therapies to increase the number and function of endogenous adult stem cells with the potential to build new bone. One option is to introduce so called mesenchymal stem cells (MSC) from the patient to bone repair sites. However, significant hurdles to autologous MSC use include the need for 2-3 week culture times to isolate MSC before application. Moreover culturing introduces infectious and immunogenic risks from prolonged exposure to animal products and cancerous risks from cellular gene changes in culture. In addition, once isolated, MSC require appropriate growth factor stimulation to form bone. Finally, MSC isolated from patient tissues such as fat or bone marrow are heterogenous and of undetermined composition—making growth factor dosing and conformance with FDA regulations for defining target product identity, purity, and potency more difficult. To circumvent these problems, we have identified and purified the cells at the origin of human MSC. We have termed these perivascular stem cells (PSC) because they are natively localized around all arteries and veins, forming the key cellular component of the natural regenerative system. In a significant breakthrough, we are able to isolate these cells within hours from adipose tissues in sufficient numbers for therapy without the need for culture. This realizes the possibility of harvesting and implanting stem cells during the same operative period. In another breakthrough, we have identified a potent growth factor NELL-1 that potently amplifies the ability of PSC to form bone and vascular structures. This has led to the development of our target PSC+NELL-1 product, which effectively stimulates and augments the body’s natural bone regenerative system by providing all the components (stem cells, growth factor, and allograft bone support structure) necessary to “jump start” as well as maintain the function of bone stem cells.
Statement of Benefit to California: 
This FDA oriented proposal focuses on crucial preparatory work required before IND-enabling preclinical studies on our Developmental Candidate for bone formation and regeneration. Our Developmental Candidate provides a complete package of stem cells, bone growth factors, and scaffold to build an optimized microenvironment to “jump start” bone formation in normal and impaired bone healing conditions. We have generated very promising preclinical data on our Developmental Candidate’s superior bone formation and regeneration efficacy. In addition to its significant impact on health care, this highly multi-disciplinary project by our team has many near-term and long-term benefits to the State of California. 1. Besides direct health costs, musculoskeletal injuries and diseases are the leading cause of work-related and physical disability in the United States. Hard working Californians are responsible for California’s annual gross domestic product of $1.8 trillion, which rank our state among the top eight largest economies in the world. By promoting the repair of both normal and healing-impaired bone in a safe and effective manner, our mature technology will reduce the loss of work productivity at the front end, reduce work disability costs, and reduce the loss of state income tax. 2. Local osteogenic stem cells decline with age (from 1/10,000 in newborns to 1/250,000 by age 30 and 1/2,000,000 by age 80), leading to osteoporosis, poor bone quality, and fragility fractures. In 1998, the health care burden for osteoporosis exceeded $2.4 billion in California alone. A whopping 64% of the $2.4 billion was caused by hip fracture. If our Development Candidate is successful in healing existing fractures in impaired bone, it may also translate to therapies to prevent fractures in impaired bone. This will significantly reduce the long-term health care burden for California’s public health insurance program. 3. This project directly adds jobs at [REDACTED] and at the California-based companies that are involved in this project. 4. This project will produce intellectual property that is owned by t [REDACTED]. Our team has a track record of attracting out of state private investment to invest in California and of procuring supplies and equipment from strategic California-based companies. 5. This mature project is precisely the type of cutting-edge, multi-disciplinary stem cell project that Californians imagined when they approved proposition 71 in 2004. The establishment of CIRM has transformed the research infrastructure at [REDACTED], increased our ability to recruit world class stem cell scientists, and attracted the attention of superb scientists from other disciplines to this new field. Working together, our team has compiled an impressive list of accomplishments and we are confident in our abilities to take this project to IND submission in a timely fashion. Funding of this project will fulfill the promise of proposition 71.
Progress Report: 
  • Background: unsuccessful bone repair
  • Most organs can regenerate cells lost to ageing, exposure to adverse conditions, ephemeral lifespan, disease or injury. Regenerative systems are complex combinations of growth factors and anchorage molecules which support, guide and control the maturation of specialized stem cells. The regenerative process may still fail, for multiple reasons. Bone fractures will sometimes not heal spontaneously because parts of the broken bone do not join anymore, or because bone regeneration itself is impaired, like in osteoporosis, a frequent condition that affects post-menopause females and elderly people of both genders.
  • A novel class of bone-healing stem cells
  • Since specialized bone-forming cells have not been identified, which stem cells could be used for the cell therapy of bone fractures? We have identified and purified novel stem cells, localized around blood vessels and therefore named perivascular stem cells (PSCs). We have also demonstrated that Nell-1, a potent osteogenic growth factor we have developed, efficiently turns PSCs into bone cells. In 2011, we have been granted support by the California Institute for Regenerative Medicine to develop a product to heal critically fractured bones in osteoporotic – or not – patients or to perform spine fusion in order to correct skeletal defects. PSCs will be purified from the patient’s own fat tissue, a well-documented, rich source of these cells, and embedded in a biocompatible scaffold in the presence of the bone forming growth factor. The resulting compound, inserted at the site of the fracture, will provide bone-forming stem cells 1-precisely characterized in terms of origin and identity; 2- derived from the patient, hence not rejected; 3- not cultured, therefore similar to their natural counterparts.
  • Progress after one year of research supported by CIRM
  • We are now close to the end of the first year of our CIRM supported studies. In this initial period we have, first, validated the stem cells of use with regard to stringent biologic criteria: how many of these cells can be purified from fat tissue? How viable and pure are these cells after the sorting process? Do stem cell numbers and quality depend on the age, sex and corpulence of the donor? Following analysis of about 80 distinct fat harvests (lipoaspirates) we have determined that robust bone forming PSC can be reliably purified, in sufficient numbers, from male and female donors in all age and weight ranges. We have also shown that PSC are at least as good, in terms of bone forming potential, than conventional mesenchymal stem cells (the candidate stem cells, so far, to be used for cell therapies of bone defects amd injuries), while being significantly superior regarding purity and safety.
  • Transplantation experiments in mice and rats have revealed that the combination of PSC and the Nell-1 growth factor ensures the most efficient bone regeneration, but that PSC do not give rise to tumors, an important verification in any protocol involving transplantation. These experiments have also demonstrated that PSC stimulate the formation of new blood vessels, an essential requisite for efficient wound healing and tissue repair.
  • Finally, we have embarked on the development of a larger animal model of bone regeneration, that will be used in the second and third years of the projects.
  • In summary, we have reached all the milestones and met the deadlines planned in the original project. The next year will see the further validation of the protocol and the beginning of the development of a stem cell/scaffold/growth factor combination product in the perspective of trials in human patients.
  • Our research group has identified in the human body a novel class of stem cells endowed with strong osteogenic potential, which means capacity to produce bone. These stem cells are attached to the outer aspect of blood vessels, and therefore present in all organs. Our ultimate goal is to use these stem cells in human beings, to perform for instance spine fusion, a procedure used to treat spine deformities (scoliosis) or faulty vertebrae, or to heal complicated bone fractures, especially in patients suffering from osteoporosis, a condition where spontaneous bone repair is compromised. We shall harvest stem cells from the patient’s own abdominal adipose (fat) tissue, a rich source of these cells which is also easy and safe to collect. Stem cells will be purified on an automated machine, named fluorescence activated cell sorter, and immobilized on an engineered biocompatible scaffold in the presence of a novel osteogenic growth factor, that is a sort of hormone which stimulates stem cell development into bone. We have won an Early Translational grant (2011-2014) from the California Institute for Regenerative Medicine to develop this project to the stage where the first clinical trials can be engaged into. In the first year, we had fully validated the stem cell population of use on a large number of human adipose samples and clearly documented the availability, efficiency and safety of these cells independently of the age, sex and weight of the donor. We had also initiated experiments in mice and rats which have been pursued during the second year, finally demonstrating unequivocally the outstanding bone forming ability of these cells in the presence of the appropriate scaffold and osteogenic hormone. We have also, during this 2nd year, developed a large animal model of stem cell mediated bone regeneration which will be indispensable prior to the inception of human treatments. Finally, we have refined the physicochemical properties of the scaffold for optimal osteogenic factor availability and bone growth. In conclusion, all milestones and deadlines included in this grant have been met and our team is steadily progressing toward the medical “translation” of these novel stem cells.
  • Our research group has identified in the human body a novel class of stem cells endowed with strong osteogenic potential, which means capacity to produce bone. These stem cells are attached to the outer aspect of blood vessels, and therefore present in all organs. Our ultimate goal is to use these stem cells in human beings, to perform for instance spine fusion, a procedure used to treat spine deformities (scoliosis) or faulty vertebrae, or to heal complicated bone fractures, especially in patients suffering from osteoporosis, a condition where spontaneous bone repair is compromised. We shall harvest stem cells from the patient’s own abdominal adipose (fat) tissue, a rich source of these cells which is also easy and safe to collect. Stem cells will be purified on an automated machine, named fluorescence activated cell sorter, and immobilized on an engineered biocompatible scaffold in the presence of a novel osteogenic growth factor, that is a sort of hormone which stimulates stem cell development into bone. We have won an Early Translational grant (2011-2014) from the California Institute for Regenerative Medicine to develop this project to the stage where the first clinical trials can be engaged into. In the first year, we had fully validated the stem cell population of use on a large number of human adipose samples and clearly documented the availability, efficiency and safety of these cells independently of the age, sex and weight of the donor. We had also initiated experiments in mice and rats which have been pursued during the second year, finally demonstrating unequivocally the outstanding bone forming ability of these cells in the presence of the appropriate scaffold and osteogenic hormone. We have also, during this 2nd year, developed a large animal model of stem cell mediated bone regeneration which will be indispensable prior to the inception of human treatments. Finally, we have refined the physicochemical properties of the scaffold for optimal osteogenic factor availability and bone growth. In conclusion, all milestones and deadlines included in this grant have been met and our team is steadily progressing toward the medical “translation” of these novel stem cells.

Systemic Adult Stem Cell Therapy for Osteoporosis-Related Vertebral Compression Fractures

Funding Type: 
Early Translational II
Grant Number: 
TR2-01780
ICOC Funds Committed: 
$1 927 698
Disease Focus: 
Bone or Cartilage Disease
Stem Cell Use: 
Adult Stem Cell
Cell Line Generation: 
Other
oldStatus: 
Active
Public Abstract: 
Vertebral compression fractures are the most common fractures associated with osteoporosis. Approximately 700,000 osteoporosis-related vertebral compression fractures (OVCFs) occur each year in the US. Currently, treatment is focused primarily on prevention. When fractures occur in patients with osteoporosis, treatment options are limited because open surgery with implants often fails. Recently, new therapies involving injection of cement into the vertebral body were developed. Unfortunately, these procedures do not regenerate bone tissue, but do incur risks of leakage and emboli. Hence, we need new treatments that directly address both the underlying cause of OVCFs (bone loss) and the inadequate repair mechanisms when fractures occur. We propose to develop a therapy that exploits mesenchymal stem cells (MSCs) stimulated in vivo with PTH (parathyroid hormone) to accelerate bone repair. PTH alone can accelerate fracture repair in healthy animals by activating bone marrow MSCs. However, osteoporotic patients have either decreased numbers of MSCs, dysfunctional MSCs, or both. In these patients, injection of MSCs combined with a PTH regimen could be an effective therapy for the treatment of multiple fractures. Our preliminary data in a mouse model demonstrated that this combined treatment enhances MSC homing to long-bone fracture sites and leads to increased repair. Here, we will build upon this foundation and ask whether a similar strategy is also effective in OVCFs. We hypothesize that PTH administration will lead to increased homing of MSCs to sites of bone fracture. We further hypothesize that PTH promotes the differentiation of MSCs into osteoblasts. Hence, our objective in the proposed study is to determine the effect of injection of MSCs combined with PTH therapy on bone regeneration in a multiple vertebral bone defect model in osteoporotic rats. The optimal doses of PTH and numbers of MSCs per injection also will be determined. Human bone marrow-derived MSCs will be injected into osteoporotic athymic rats with multiple lumbar vertebral bone defects. MSC homing to bone defects will be monitored using micro- and molecular imaging. Subsequent studies will test increasing dosages of PTH to define the optimal dose for maximal enhancement of MSC homing to a fracture. Bone regeneration will be monitored using micro–CT imaging and biomechanical analyses (to determine structural integrity of newly repaired bone). Subsequent studies will determine whether increasing the number of injected MSCs linearly enhances bone tissue formation. These studies will aid in the creation of an evidence base for future clinical trials that could revolutionize the treatment of vertebral fractures and other complex fractures in patients suffering from osteoporosis.
Statement of Benefit to California: 
Approximately 10 million people in the United States are diagnosed as osteoporotic, while an additional 34 million are classified as having low bone mass. The lifetime incidence of fragility fractures secondary to osteoporosis in females over fifty years of age is approximately 1 in 2, and in males over the age of fifty, is 1 in 4. Osteoporosis-related vertebral compression fractures (OVCFs) are the most common fragility fractures in the United States, accounting for approximately 700,000 injuries per year, twice the rate of hip fractures. Approximately 70,000 OVCFs result in hospitalization each year with an average hospital stay per patient of 8 days. Fragility fractures due to osteoporosis also place a severe financial strain upon the health care industry. Estimates show there were approximately 1.5 million osteoporosis-related fractures in the United States in 2001, the care of which cost about $17 billion. Moreover, as the number of individuals over the age of fifty continues to increase, costs are predicted to rise to an estimated $60 billion a year by the year 2030. OVCFs have previously received limited attention from the spine care community. This oversight may be a result of the perception that OVCFs are benign, self-limited problems or that treatment options are limited. However, it has become clear that OVCFs are associated with significant physiologic and functional impairment, even in patients not presenting for medical evaluation at the time of fracture. Current treatment of osteoporotic patients is mostly focused on prevention of OVCFs. There are a few options of treatment when OVCFs actually occur. Since open surgery involves morbidity and implant failure in the osteoporotic patient population, nonoperative management, including medications and bracing, is usually recommended for the vast majority of patients. Unfortunately, large numbers of patients report intractable pain and inability to return to activities. Currently there is no efficient biological solution for the treatment of OVCFs. The proposed study will further develop a biological therapeutic solution that will accelerate repair of OVCFs. The treatment will rely upon a combination of drug and adult stem cell therapy; both are either approved for clinical use or in clinical trials. It will also involve a simple intravenous injection instead of a percutaneous injection of a polymer, which does not restore lost bone tissue. Data generated form this study could potentially revolutionize the treatment of vertebral fractures and other complex fractures in patients suffering from osteoporosis, and so benefit the citizens of California by reducing hospitalization periods, operative costs and loss of workdays, and by improving quality of life for Californians with osteoporosis that are at risk for OVCFs.
Progress Report: 
  • The goal of the proposed study is to develop a treatment for accelerating multiple vertebral fracture repairs. Approximately 10 million people in the United States are diagnosed as osteoporotic, while an additional 34 million are classified as having low bone mass. The lifetime incidence of fragility fractures secondary to osteoporosis in females over the age of fifty years of age is approximately 1 in 2, and in males over the age of fifty, is 1 in 4. Vertebral compression fractures (VCFs) are the most common fragility fractures in the United States, accounting for approximately 700,000 injuries per year, twice the rate of hip fractures. Approximately 70,000 VCFs result in hospitalization each year with an average hospital stay per patient of 8 days. Current treatment of osteoporotic patients is mostly focused on prevention of VCFs mainly using new medicines such as Alendronate and Parathyroid Hormone (1-34). But there are a few options of treatment when VCFs actually occur. New, non-biological, methods have been developed to regain the biomechanical properties of a fractured vertebral body. These methods include the minimally invasive procedures of vertebroplasty and balloon tamp reduction. Both procedures involve injection of synthetic nonbiological material that does not resorb and instead remains a permanent foreign-body fixture in the spine. Ultimately, a biological solution that would promote rapid fracture healing and stimulate normal bone production would be the best for osteoporotic patients with vertebral column injuries. Our pilot studies have shown that bone fractures can be treated by intravenous administration of adult stem cells combined with a dose of parathyroid hormone, which is approved by the FDA for use as an anabolic agent in the treatment of severe osteoporosis. Therefore, in the proposed project we will determine the ability of injected stem cells to migrate to a vertebral fracture site. We will also analyze the combined effect of PTH and stem cells on vertebral fracture repair.
  • The goal of the study is to develop a treatment for accelerating multiple vertebral fracture repair. Approximately 10 million people in the United States are diagnosed as osteoporotic, while an additional 34 million are classified as having low bone mass. Vertebral compression fractures (VCFs) are the most common fractures in the United States, accounting for approximately 700,000 injuries per year, twice the rate of hip fractures. Approximately 70,000 VCFs result in hospitalization each year with an average hospital stay per patient of 8 days. Current treatment of osteoporotic patients is mostly focused on prevention of VCFs mainly using new medicines such as Alendronate and Parathyroid Hormone (PTH). But there are no options of treatment when VCFs actually occur either than bed rest and pain medication.
  • Our goal is to induce efficient vertebral fracture repair by a combined treatment of adult stem cells and PTH. During the last year we treated osteoporotic animals (rodents) with human stem cells, isolated from bone marrow. The cells were injected to the blood circulation followed by PTH treatment for three weeks. In order to evaluate whether the injected cells migrated to the region of the spinal fractures, we used fluorescent cells. Using a highly sensitive camera we were able to track the injected cells in the body of the animals over 55 days. Our results showed that more cells targeted the spine region when PTH was given to the animals compared to a control group that did not receive PTH. In addition, we analyzed the effect of the stem cell treatment on the repair of spinal fractures. Using high resolution CT imaging we found that osteoporotic animals treated with stem cells and PTH had significantly more bone fracture repair when compared to untreated animals and to animals treated with PTH or stem cells only.
  • In conclusion, we have generated promising results demonstrating the efficiency of stem cell therapy combined with PTH for the treatment of vertebral fractures. We will further explore this effect in the 3rd year of the project, aiming to promote this therapy further towards clinical use.
  • During the 3rd year of the project we have been able to show that when stem cells are injected to osteoporotic animals, they migrate and home to vertebral fractures. We also showed that treating the animals with an FDA-approved drug, PTH, enhances the homing of the stem cells (i.e. more cells migrate to the site of the fracture). Using microscopy and specific fluorescent dyes we were able to investigate the fate of the injected stem cells after they arrived to the fracture site. Apparently these cells turn into bone-forming cells and participate in the fracture repair. Indeed, when we measured the repair of the vertebral fractures (i.e. amount of new bone that was formed) we found that the combination therapy of stem cells and PTH had a superior effect compared to the therapies that included only stem cells or were left untreated. We are currently evaluating the use of lower doses of PTH that are equivalent to the dose used for prevention of fractures in osteoporosis patients. In summary, we believe that our results so far merit further investigation of the proposed therapy that might prove beneficial of numerous patients suffering from vertebral compression fractures every year.

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