Bone or Cartilage Disease

Coding Dimension ID: 
279
Coding Dimension path name: 
Bone or Cartilage Disease
Funding Type: 
Preclinical Development Awards
Grant Number: 
PC1-08128
Investigator: 
Institution: 
Type: 
PI
ICOC Funds Committed: 
$7 660 211
Disease Focus: 
Bone or Cartilage Disease
Stem Cell Use: 
Embryonic Stem Cell
Public Abstract: 

Surgical approaches to the treatment of focal cartilage defects can be classified into repair, replacement, and regeneration therapies. Marrow stimulation procedures such as microfracture result in a repair tissue that is predominantly fibrocartilaginous in nature, which is mechanically less durable than articular cartilage and survives on average 7 years before requiring another procedure. Osteochondral grafting (autologous or allogeneic) replaces the defect with fresh mature cartilage and bone. While the tissue replicates natural cartilage, the grafted cartilage does not integrate or bond with the host tissue. Autologous chondrocyte implantation (ACI) attempts to regenerate tissue by injecting chondrocytes into the defect. Results with this technique are mixed with several randomized clinical trials failing to find a clinically and statistically significant benefit over microfracture or other procedures.
Our approach is to advance third-generation cell therapy by constructing scaffolds that are seeded with chondroprogenitor cells programmed to undergo differentiation into bone and cartilage cells. If successful, this will be the first-in-man embryonic stem-cell-based treatment of an orthopaedic disease that has challenged repeated attempts over the last 400 years. The product has the unique advantage that the same material is universally applicable in all patients with a range of different defect shapes and sizes. The preclinical development, characterization, efficacy, and safety will also support and advance stem-cell-based regenerative medicine in general.

Statement of Benefit to California: 

Arthritis is a common disease and increases with age. The annual cost of treating arthritis in the US is estimated to be over $200B in 2013. Over a million joint replacements are performed in the US alone for end-stage arthritis. However, for younger patients with severe arthritis or impending arthritis there is as yet no treatment that can prevent, cure, or even slow the progression of this disease. In this proposal. we target bone and cartilage defects that are a major factor in contributing to early osteoarthritis in patients less than 55 years of age. Our approach is to advance third-generation cell therapy by constructing scaffolds that are seeded with chondroprogenitor cells programmed to undergo differentiation into bone and cartilage cells. This proposal falls under the mission statement of CIRM for funding innovative research. A stem-cell-based approach for treating articular cartilage defects in not represented in CIRM’s current portfolio. If successful, this will be the first-in-man embryonic stem-cell-based treatment of an orthopaedic disease that has challenged repeated attempts over the last 400 years. This will further validate the significance of the CIRM program and help maintain California’s leading position at the cutting edge of biomedical research.

Funding Type: 
Early Translational I
Grant Number: 
TR1-01249
Investigator: 
Name: 
Institution: 
Type: 
PI
ICOC Funds Committed: 
$6 762 954
Disease Focus: 
Bone or Cartilage Disease
Stem Cell Use: 
Adult Stem Cell
oldStatus: 
Active
Public Abstract: 

All adult tissues contain stem cells. Some tissues, like bone marrow and skin, harbor more adult stem cells; other tissues, like muscle, have fewer. When a tissue or organ is injured these stem cells possess a remarkable ability to divide and multiply. In the end, the ability of a tissue to repair itself seems to depend on how many stem cells reside in a particular tissue, and the state of those stem cells. For example, stress, disease, and aging all diminish the capacity of adult stem cells to self-renew and to proliferate, which in turn hinders tissue regeneration.

Our strategy is to commandeer the molecular machinery responsible for adult stem cell self-renewal and proliferation and by doing so, stimulate the endogenous program of tissue regeneration. This approach takes advantage of the solution that Nature itself developed for repairing damaged or diseased tissues, and controls adult stem cell proliferation in a localized, highly controlled fashion. This strategy circumvents the immunological, medical, and ethical hurdles that exist when exogenous stem cells are introduced into a human. When utilizing this strategy the goal of reaching clinical trials in human patients within 5 years becomes realistic.

Specifically, we will target the growing problem of neurologic, musculoskeletal, cardiovascular, and wound healing diseases by local delivery of a protein that promotes the body’s inherent ability to repair and regenerate tissues. We have evidence that this class of proteins, when delivered locally to an injury site, is able to stimulate adult tissue stem cells to grow and repair/replace the deficient tissue following injury. We have developed technologies to package the protein in a specialized manner that preserves its biological activity but simultaneously restricts its diffusion to unintended regions of the body. For example, when we treat a skeletal injury with this packaged protein we augment the natural ability to heal bone by 350%; and when this protein is delivered to the heart immediately after an infarction cardiac output is improved and complications related to scarring are reduced. This remarkable capacity to augment tissue healing is not limited to bones and the heart: the same powerful effect can be elicited in the brain, and skin injuries.

The disease targets of stroke, bone fractures, heart attacks, and skin wounds and ulcers represent an enormous health care burden now, but this burden is expected to skyrocket because our population is quickly aging. Thus, our proposal addresses a present and ongoing challenge to healthcare for the majority of Californians, with a novel therapeutic strategy that mimics the body’s inherent repair mechanisms.

Statement of Benefit to California: 

Californians represent 1 in 7 Americans, and make up the single largest healthcare market in the United States. The diseases and injuries that affect Californians affect the rest of the US, and the world. For example, stroke is the third leading cause of death, with more than 700,000 people affected every year. It is a leading cause of serious long-term disability, with an estimated 5.4 million stroke survivors currently alive today. Symptoms of musculoskeletal disease are the number two most cited reasons for visit to a physician. Musculoskeletal disease is the leading cause of work-related and physical disability in the United States, with arthritis being the leading chronic condition reported by the elderly. In adults over the age of 70, 40% suffer from osteoarthritis of the knee and of these nearly 80% have limitation of movement. By 2030, nearly 67 million US adults will be diagnosed with arthritis. Cardiovascular disease is the leading cause of death, and is a major cause of disability worldwide. The annual socioeconomic burden posed by cardiovascular disease is estimated to exceed $400 billion annually and remains a major cause of health disparities and rising health care costs. Skin wounds from burns, trauma, or surgery, and chronic wounds associated with diabetes or pressure ulcer, exact a staggering toll on our healthcare system: Burns alone affect 1.25M Americans each year, and the economic global burden of these injuries approaches $50B/yr. In California alone, the annual healthcare expenditures for stroke, skeletal repair, heart attacks, and skin wound healing are staggering and exceed 700,000 cases, 3.5M hospital days, and $34B.

We have developed a novel, protein-based therapeutic platform to accelerate and enhance tissue regeneration through activation of adult stem cells. This technology takes advantage of a powerful stem cell factor that is essential for the development and repair of most of the body’s tissues. We have generated the first stable, biologically active recombinant Wnt pathway agonist, and showed that this protein has the ability to activate adult stem cells after tissue injury. Thus, our developmental candidate leverages the body’s natural response to injury. We have generated exciting preclinical results in a variety of animals models including stroke, skeletal repair, heart attack, and skin wounding. If successful, this early translational award would have enormous benefits for the citizens of California and beyond.

Progress Report: 
  • In the first year of CIRM funding our objectives were to optimize the activity of the Wnt protein for use in the body and then to test, in a variety of injury models, the effects of this lipid-packaged form of Wnt. We have made considerable progress on both of these fronts. For example, in Roel Nusse and Jill Helms’ groups, we have been able to generate large amounts of the mouse form of Wnt3a protein and package it into liposomal vesicles, which can then be used by all investigators in their studies of injury and repair. Also, Roel Nusse succeeded in generating human Wnt3a protein. This is a major accomplishment since our ultimate goal is to develop this regenerative medicine tool for use in humans. In Jill Helms’ lab we made steady progress in standardizing the activity of the liposomal Wnt3a formulation, and this is critically important for all subsequent studies that will compare the efficacy of this treatment across multiple injury repair scenarios.
  • Each group began testing the effects of liposomal Wnt3a treatment for their particular application. For example, in Theo Palmer’s group, the investigators tested how liposomal Wnt3a affected cells in the brain following a stroke. We previously found that Wnt3A promotes the growth of neural stem cells in a petri dish and we are now trying to determine if delivery of Wnt3A can enhance the activity of endogenous stem cells in the brain and improve the level of recovery following stroke. Research in the first year examined toxicity of a liposome formulation used to deliver Wnt3a and we found it to be well tolerated after injection into the brains of mice. We also find that liposomal Wnt3a can promote the production of new neurons following stroke. The ongoing research involves experiments to determine if these changes in stem cell activity are accompanied by improved neurological function. In Jill Helms’ group, the investigators tested how liposomal Wnt3a affected cells in a bone injury site. We made a significant discovery this year, by demonstrating that liposomal Wnt3a stimulates the proliferation of skeletal progenitor cells and accelerates their differentiation into osteoblasts (published in Science Translational Medicine 2010). We also started testing liposomal Wnt3a for safety and toxicity issues, both of which are important prerequisites for use of liposomal Wnt3a in humans. Following a heart attack (i.e., myocardial infarction) we found that endogenous Wnt signaling peaks between post-infarct day 5-7. We also found that small aggregates of cardiac cells called cardiospheres respond to Wnt in a dose-responsive manner. In skin wounds, we tested the effect of boosting Wnt signaling during skin wound healing. We found that the injection of Wnt liposomes into wounds enhanced the regeneration of hair follicles, which would otherwise not regenerate and make a scar instead. The speed and strength of wound closure are now being measured.
  • In aggregate, our work on this project continues to move forward with a number of great successes, and encouraging data to support our hypothesis that augmenting Wnt signaling following tissue injury will provide beneficial effects.
  • In the second year of CIRM funding our objectives were to optimize packaging of the developmental candidate, Wnt3a protein, and then to continue to test its efficacy to enhance tissue healing. We continue to make considerable progress on the stated objectives. In Roel Nusse’s laboratory, human Wnt3a protein is now being produced using an FDA-approved cell line, and Jill Helms’ lab the protein is effectively packaged into lipid particles that delay degradation of the protein when it is introduced into the body.
  • Each group has continued to test the effects of liposomal Wnt3a treatment for their particular application. In Theo Palmer’s group we have studied how liposomal Wnt3a affects neurogenesis following stroke. We now know that liposomal Wnt3a transiently stimulates neural progenitor cell proliferation. We don’t see any functional improvement after stroke, though, which is our primary objective.
  • In Jill Helms’ group we’ve now shown that liposomal Wnt3a enhances fracture healing and osseointegration of dental and orthopedic implants and now we demonstrate that liposomal Wnt3a also can improve the bone-forming capacity of bone marrow grafts, especially when they are taken from aged animals.
  • We’ve also tested the ability of liposomal Wnt3a to improve heart function after a heart attack (i.e., myocardial infarction). Small aggregates of cardiac progenitor cells called cardiospheres proliferate to Wnt3a in a dose-responsive manner, and we see an initial improvement in cardiac function after treatment of cells with liposomal Wnt3a. the long-term improvements, however, are not significant and this remains our ultimate goal. In skin wounds, we tested the effect of boosting Wnt signaling during wound healing. We found that the injection of liposomal Wnt3a into wounds enhanced the regeneration of hair follicles, which would otherwise not regenerate and make a scar instead. The speed of wound closure is also enhanced in regions of the skin where there are hair follicles.
  • In aggregate, our work continues to move forward with a number of critical successes, and encouraging data to support our hypothesis that augmenting Wnt signaling following tissue injury will provide beneficial effects.
  • Every adult tissue harbors stem cells. Some tissues, like bone marrow and skin, have more adult stem cells and other tissues, like muscle or brain, have fewer. When a tissue is injured, these stem cells divide and multiply but only to a limited extent. In the end, the ability of a tissue to repair itself seems to depend on how many stem cells reside in a particular tissue, and the state of those stem cells. For example, stress, disease, and aging all diminish the capacity of adult stem cells to respond to injury, which in turn hinders tissue healing. One of the great unmet challenges for regenerative medicine is to devise ways to increase the numbers of these “endogenous” stem cells, and revive their ability to self-renew and proliferate.
  • The scientific basis for our work rests upon our demonstration that a naturally occurring stem cell growth factor, Wnt3a, can be packaged and delivered in such a way that it is robustly stimulates stem cells within an injured tissue to divide and self-renew. This, in turn, leads to unprecedented tissue healing in a wide array of bone injuries especially in aged animals. As California’s population ages, the cost to treat such skeletal injuries in the elderly will skyrocket. Thus, our work addresses a present and ongoing challenge to healthcare for the majority of Californians and the world, and we do it by mimicking the body’s natural response to injury and repair.
  • To our knowledge, there is no existing technology that displays such effectiveness, or that holds such potential for the stem cell-based treatment of skeletal injuries, as does a L-Wnt3a strategy. Because this approach directly activates the body’s own stem cells, it avoids many of the pitfalls associated with the introduction of foreign stem cells or virally reprogrammed autologous stem cells into the human body. In summary, our data show that L-Wnt3a constitutes a viable therapeutic approach for the treatment of skeletal injuries, especially those in individuals with diminished healing potential.
  • This progress report covers the period between Sep 01 2012through Aug 31 2013, and summarizes the work accomplished under ET funding TR1-01249. Under this award we developed a Wnt protein-based platform for activating a patient’s own stem cells for the purpose of tissue regeneration.
  • At the beginning of our grant period we generated research grade human WNT3A protein in quantities sufficient for all our discovery experiments. We then tested the ability of this WNT protein therapeutic to improve the healing response in animal models of stroke, heart attack, skin wounding, and bone fracture. These experimental models recapitulated some of the most prevalent and debilitating human diseases that collectively, affect millions of Californians.
  • At the end of year 2, we assembled an external review panel to select the promising clinical indication. The scientific advisory board unanimously selected skeletal repair as the leading indication. The WNT protein is notoriously difficult to purify; consequently in year 3 we developed new methods to streamline the purification of WNT proteins, and the packaging of the WNT protein into liposomal vesicles that stabilized the protein for in vivo use.
  • In years 3 and 4 we continued to accrue strong scientific evidence in both large and small animal models that a WNT protein therapeutic accelerates bone regeneration in critical size bony non-unions, in fractures, and in cases of implant osseointegration. In this last year of funding, we clarified and characterized the mechanism of action of the WNT protein, by showing that it activates endogenous stem cells, which in turn leads to faster healing of a range of different skeletal defects.
  • In this last year we also identified a therapeutic dose range for the WNT protein, and developed a route and method of delivery that was simultaneously effective and yet limited the body’s exposure to this potent stem cell factor. We initiated preliminary safety studies to identify potential risks, and compared the effects of WNT treatment with other commercially available bone growth factors. In sum, we succeeded in moving our early translational candidate from exploratory studies to validation, and are now ready to enter into the IND-enabling phase of therapeutic candidate development.
  • This progress report covers the period between Sep 01 2013 through April 30 2014, and summarizes the work accomplished under ET funding TR101249. Under this award we developed a Wnt protein-based platform for activating a patient’s own stem cells for purposes of tissue regeneration.
  • At the beginning of our grant period we generated research grade human WNT3A protein in quantities sufficient for all our discovery experiments. We then tested the ability of this WNT protein therapeutic to improve the healing response in animal models of stroke, heart attack, skin wounding, and bone fracture. These experimental models recapitulated some of the most prevalent and debilitating human diseases that collectively, affect millions of Californians. At the conclusion of Year 2 an external review panel was assembled and charged with the selection of a single lead indication for further development. The scientific advisory board unanimously selected skeletal repair as the lead indication.
  • In year 3 we accrued addition scientific evidence, using both large and small animal models, demonstrating that a WNT protein therapeutic accelerated bone healing. Also, we developed new methods to streamline the purification of WNT proteins, and improved our method of packaging of the WNT protein into liposomal vesicles (e.g., L-WNT3A) for in vivo use.
  • In year 4 we clarified the mechanism of action of L-WNT3A, by demonstrating that it activates endogenous stem cells and therefore leads to accelerated bone healing. We also continued our development studies, by identifying a therapeutic dose range for L-WNT3A, as well as a route and method of delivery that is both effective and safe. We initiated preliminary safety studies to identify potential risks, and compared the effects of L-WNT3A with other, commercially available bone growth factors.
  • In year 5 we initiated two new preclinical studies aimed at demonstrating the disease-modifying activity of L-WNT3A in spinal fusion and osteonecrosis. These two new indications were chosen by a CIRM review panel because they represent an unmet need in California and the nation. We also initiated development of a scalable manufacturing and formulation process for both the WNT3A protein and L-WNT3A formulation. These two milestones were emphasized by the CIRM review panel to represent major challenges to commercialization of L-WNT3A; consequently, accomplishment of these milestones is a critical yardstick by which progress towards an IND filing can be assessed.
  • With regards to objective 1, we employed established animal models of spinal fusion and osteonecrosis to demonstrate the disease-mitigating activity of our Developmental Candidate, autograftWNT.
  • With regards to objective 2, the mechanism of L-WNT3A action has been demonstrated in ex vivo, non-GLP pharmacology studies.
  • With regards to objective 3, we have completed characterization of the non-GLP substance, WNT3A drug product, and the drug product, L-WNT3A. Methods for reproducible and scaleable research grade production of the drug substance WNT3A, and the drug product, L-WNT3A, have been developed (see below for details). A serum free process has been achieved.
Funding Type: 
Tools and Technologies III
Grant Number: 
RT3-07804
Investigator: 
Name: 
Institution: 
Type: 
PI
ICOC Funds Committed: 
$1 452 708
Disease Focus: 
Bone or Cartilage Disease
Stem Cell Use: 
Adult Stem Cell
Public Abstract: 

Despite the great promise stem cells hold for regenerative medicine, the efficacy of stem cell-based therapies is greatly limited by poor cell engraftment and survival. To overcome this major bottleneck, the goal of this proposal is to validate the efficacy of novel microribbon (µRB)-based scaffolds for cell delivery. These scaffolds combine the injectability and cell encapsulation of conventional hydrogels with macroporosity, which facilitates nutrient transfer, cell survival, proliferation, and tissue formation. In preliminary studies, our µRB-based scaffolds markedly enhanced the survival of human stem cells and accelerated bone repair in vivo. Thus, here we propose to validate the efficacy of µRB-like hydrogels with tunable stiffness and macroporosity as cell-delivery matrices that enhance the engraftment and survival of stem cells for both soft and hard tissue reconstruction using relevant animal models in vivo. Our results will significantly accelerate clinical translation of stem cell-based therapy by enhancing cell delivery, survival, and integration, thus improving therapeutic outcomes, reducing the number of cells needed for transplantation, and reducing the associated time and cost to produce these cells. Our validated platform will be broadly applicable to diverse cell types, and its wide dissemination will crucially advance the translation of stem cell-based therapies to combat both acute and degenerative human conditions

Statement of Benefit to California: 

Tissue loss and organ failure represents a substantial socioeconomic burden to the State of California, with increasing medical costs for treating patients suffering from various degenerative disease, trauma and congenital defects. Furthermore, the average life-span and percentage of aging population in California is expected to grow, with increasing needs for better therapeutic strategies for caring these patients. Stem cell-based therapies hold great promise for treating tissue loss and enhancing tissue regeneration, often via direct injection of cells at the target site. However, the majority of transplanted cells die shortly after transplantation, which greatly diminishes the efficacy of stem cell-based therapies. Poor cell engraftment and survival remain a major bottleneck to fully exploiting the power of stem cells for regenerative medicine. Here we propose to validate the efficacy of novel µRB-like hydrogels as cell-delivery matrices that enhance the engraftment and survival of stem cells for both soft and hard tissue reconstruction. Our results will significantly accelerate clinical translation of stem cell-based therapy for residents in California by enhancing cell delivery, survival, and integration, thus improving therapeutic outcomes. Our validated platform will be broadly applicable to diverse cell types, and its wide dissemination will crucially advance the translation of stem cell-based therapies to combat both acute and degenerative human conditions.

Funding Type: 
Preclinical Development Awards
Grant Number: 
PC1-08142
Investigator: 
ICOC Funds Committed: 
$2 633 592
Disease Focus: 
Bone or Cartilage Disease
Stem Cell Use: 
Adult Stem Cell
Public Abstract: 

Osteoarthritis (OA) is the most prevalent musculoskeletal disease affecting nearly 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. 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. Targeting resident stem cells pharmacologically also avoids the risks and costs associated with cell-based approaches. In previous preclinical studies we have identified a small molecule drug candidate that specifically induces chondrocyte differentiation in culture and improves cartilage repair in OA animal models. In the proposed study we will optimize the regimen for dose, frequency and duration. We will also profile the preclinical candidate (PCC) for physicochemical, pharmacological and toxicological properties, draft a detailed plan for phase 1 clinical trial, and prepare documents and conduct a pre-IND meeting with the FDA. If successful, we will initiate IND-enabling studies and subsequent phase 1 clinical trial for the PCC.

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.

Funding Type: 
Early Translational II
Grant Number: 
TR2-01829
Investigator: 
Type: 
PI
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 .
Funding Type: 
Disease Team Therapy Development - Research
Grant Number: 
DR2A-05302
Investigator: 
Name: 
Type: 
PI
Name: 
Type: 
Co-PI
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.
Funding Type: 
Early Translational IV
Grant Number: 
TR4-06713
Investigator: 
Name: 
Type: 
PI
Name: 
Type: 
Co-PI
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.
Funding Type: 
Tools and Technologies III
Grant Number: 
RT3-07981
Investigator: 
Name: 
Type: 
PI
Type: 
Co-PI
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.

Funding Type: 
Early Translational III
Grant Number: 
TR3-05709
Investigator: 
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.
Funding Type: 
Disease Team Therapy Planning I
Grant Number: 
DR2-05302
Investigator: 
Name: 
Type: 
PI
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.

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