odanacatib and Osteoporotic-Fractures

There is a need for the development of new drugs to prevent osteoporosis-related fractures. Fractures are projected to increase and the present drugs have modest efficacy, significant side-effects and poor compliance. To illustrate the difficulties in the development of new drugs, the author reviews the fate of several drugs that have failed to gain regulatory approval. These drugs include arzoxifene, lasofoxifene, MK-5442, roncalceret and odanacatib. Romosozumab and abaloparatide are the only new drugs presently in phase-3 development. It is anticipated that ongoing studies of the mechanisms and signaling pathways involved in the regulation of bone remodeling will open up new opportunities for targeted pharmacological interventions to increase bone strength. However, the perfect drug is still a long way off and will face many obstacles before approval.

Topics: Benzoates; Biphenyl Compounds; Bone Density Conservation Agents; Drug Discovery; Humans; Osteoporosis; Osteoporotic Fractures; Piperidines; Propanolamines; Pyrrolidines; Tetrahydronaphthalenes; Thiophenes

Osteoporosis is a metabolic bone disease that is characterized by heightened state of bone resorption accompanied by diminished bone formation, leading to a reduction of bone mineral density (BMD) and deterioration of bone quality, thus increasing the risk of developing fractures. Molecular insight into bone biology identified cathepsin K (CatK) as a novel therapeutic target. CatK is a lysosomal cysteine protease secreted by activated osteoclasts during bone resorption, whose primary substrate is type I collagen, the major component of organic bone matrix. Available anti-resorptive drugs affect osteoclast survival and influence both resorption and formation of bone. CatK inhibitors are distinct from the existing anti-resorptives as they only target the resorption process itself without impairing osteoclast differentiation and do not interfere with bone formation. An inhibitor of CatK, odanacatib, robustly increased both trabecular and cortical BMD in postmenopausal osteoporosis patients. The phase III fracture prevention trial with odanacatib ended early due to good efficacy and a favorable benefit/risk profile, thus, enhancing the opportunity for CatK as a pharmacological target for osteoporosis. So far, all the inhibitors that reached to the stage of clinical trial targeted active site of CatK to abrogate the entire proteolytic activity of the enzyme in addition to the desired blockage of excessive elastin and collagen degradation, and could thus pose safety concerns with long term use. Identification of selective exosite inhibitors that inhibit CatK's elastase and/or collagenase activity but do not affect the hydrolysis of other physiologically relevant substrates of CatK would be an improved strategy to inhibit this enzyme.

Topics: Aged; Animals; Biphenyl Compounds; Bone and Bones; Bone Density Conservation Agents; Cathepsin K; Cysteine Proteinase Inhibitors; Drugs, Investigational; Female; Humans; Molecular Targeted Therapy; Osteoclasts; Osteoporosis, Postmenopausal; Osteoporotic Fractures

Osteoporosis is a significant public health issue affecting over half of women aged over 50. With an aging population, its importance is set to increase further over time. Prevention of fragility fractures avoids significant mortality and morbidity as well as saving significant direct and indirect costs to the economy. In this review, we discuss existing treatments to contextualize the treatment landscape, and demonstrate how our understanding of bone pathophysiology has led to novel therapies-in the form of combinations and altered durations of existing treatments, as well as newer drug therapies.. PubMed and Embase were searched for randomized controlled trials of new therapies for osteoporosis. These searches were supplemented with material presented in abstract form at international meetings.. New drugs that appear promising in the treatment of osteoporosis include the cathepsin K inhibitor, monoclonal antibodies against sclerostin and parathyroid hormone-related protein analog.. Separate to the development of novel drug therapies is the issue of how best to use agents that are currently available to us; specifically which agent to choose, alone or in combination; duration of therapy; how best to identify patients at highest risk of fracture, and to ensure the highest possible adherence to medication. Many of these issues have been addressed in other excellent review papers, and will not be considered in detail here.. As with all new treatments, we await results of long-term use and experience in 'real life' patient populations.. As alluded to above, data are urgently required regarding the optimal duration of therapy; use of combination therapy; ordering of therapies for best therapeutic effect. As stratified medicine becomes more strongly considered in all areas of therapy, its merits in osteoporosis as in other musculoskeletal conditions, is timely and valuable.

Topics: Biphenyl Compounds; Bone Density; Bone Density Conservation Agents; Calcium, Dietary; Cathepsin K; Dietary Supplements; Diphosphonates; Humans; Osteoporosis; Osteoporotic Fractures; Parathyroid Hormone-Related Protein; Randomized Controlled Trials as Topic; Treatment Outcome; Vitamin D

Progress continues to be made in the development of therapeutics for fracture prevention. Bisphosphonates are now available orally and intravenously, often as inexpensive generics, and remain the most widely used interventions for osteoporosis. The major safety concern associated with the use of bisphosphonates is the development of femoral shaft stress fractures and, although rare, this adverse event affords the principal rationale for restricting bisphosphonate therapy to those individuals with femoral T-scores <-2.5, and for providing drug holidays in those individuals requiring therapy for >5 years. Newer antiresorptive therapies, in the form of denosumab and cathepsin K inhibitors, might increase efficacy and possibly circumvent some of the safety concerns associated with bisphosphonate use (for example, gastrointestinal and renal complications). The combination of teriparatide with antiresorptives markedly increases effects on BMD; new anabolic agents are also very promising in this regard. However, whether or not these changes in BMD translate into improved efficacy of fracture prevention remains to be determined. Vitamin D is important for the prevention of osteomalacia, but does not influence BMD or fracture risk in patients not deficient in vitamin D. The balance of risks and benefits of calcium supplementation is contentious, but patients should be encouraged to adhere to a balanced diet aimed at maintaining a healthy body weight. Consideration of a patient's risk of falling, and its mitigation, are also important. In this Review, I summarize the short-term and long-term effects of osteoporosis therapies.

Topics: Adaptor Proteins, Signal Transducing; Antibodies, Monoclonal; Biphenyl Compounds; Bone Density Conservation Agents; Bone Morphogenetic Proteins; Calcium; Cathepsin K; Denosumab; Diphosphonates; Estrogens; Genetic Markers; Humans; Osteoporosis; Osteoporotic Fractures; Parathyroid Hormone; Strontium; Treatment Outcome; Vitamin D

Osteoporosis is a common disease characterised by a systemic impairment of bone mass and microarchitecture that results in fragility fractures. With an ageing population, the medical and socioeconomic effect of osteoporosis, particularly postmenopausal osteoporosis, will increase further. A detailed knowledge of bone biology with molecular insights into the communication between bone-forming osteoblasts and bone-resorbing osteoclasts and the orchestrating signalling network has led to the identification of novel therapeutic targets. Novel treatment strategies have been developed that aim to inhibit excessive bone resorption and increase bone formation. The most promising novel treatments include: denosumab, a monoclonal antibody for receptor activator of NF-κB ligand, a key osteoclast cytokine; odanacatib, a specific inhibitor of the osteoclast protease cathepsin K; and antibodies against the proteins sclerostin and dickkopf-1, two endogenous inhibitors of bone formation. This overview discusses these novel therapies and explains their underlying physiology.

Topics: Absorptiometry, Photon; Adaptor Proteins, Signal Transducing; Aged; Aged, 80 and over; Anabolic Agents; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Benzodioxoles; Biphenyl Compounds; Bone Density; Bone Density Conservation Agents; Bone Morphogenetic Proteins; Bone Remodeling; Bone Resorption; Calcium; Denosumab; Diphosphonates; Female; Genetic Markers; Humans; Intercellular Signaling Peptides and Proteins; Middle Aged; Osteoblasts; Osteoclasts; Osteoporosis; Osteoporosis, Postmenopausal; Osteoporotic Fractures; Quinazolines; Randomized Controlled Trials as Topic; RANK Ligand; Risk Assessment; Risk Factors; Vitamin D Deficiency; Wnt Proteins

Odanacatib, a cathepsin K inhibitor, reduces bone resorption while maintaining bone formation. Previous work has shown that odanacatib increases bone mineral density in postmenopausal women with low bone mass. We aimed to investigate the efficacy and safety of odanacatib to reduce fracture risk in postmenopausal women with osteoporosis.. The Long-term Odanacatib Fracture Trial (LOFT) was a multicentre, randomised, double-blind, placebo-controlled, event-driven study at 388 outpatient clinics in 40 countries. Eligible participants were women aged at least 65 years who were postmenopausal for 5 years or more, with a femoral neck or total hip bone mineral density T-score between -2·5 and -4·0 if no previous radiographic vertebral fracture, or between -1·5 and -4·0 with a previous vertebral fracture. Women with a previous hip fracture, more than one vertebral fracture, or a T-score of less than -4·0 at the total hip or femoral neck were not eligible unless they were unable or unwilling to use approved osteoporosis treatment. Participants were randomly assigned (1:1) to either oral odanacatib (50 mg once per week) or matching placebo. Randomisation was done using an interactive voice recognition system after stratification for previous radiographic vertebral fracture, and treatment was masked to study participants, investigators and their staff, and sponsor personnel. If the study completed before 5 years of double-blind treatment, consenting participants could enrol in a double-blind extension study (LOFT Extension), continuing their original treatment assignment for up to 5 years from randomisation. Primary endpoints were incidence of vertebral fractures as assessed using radiographs collected at baseline, 6 and 12 months, yearly, and at final study visit in participants for whom evaluable radiograph images were available at baseline and at least one other timepoint, and hip and non-vertebral fractures adjudicated as being a result of osteoporosis as assessed by clinical history and radiograph. Safety was assessed in participants who received at least one dose of study drug. The adjudicated cardiovascular safety endpoints were a composite of cardiovascular death, myocardial infarction, or stroke, and new-onset atrial fibrillation or flutter. Individual cardiovascular endpoints and death were also assessed. LOFT and LOFT Extension are registered with ClinicalTrials.gov (number NCT00529373) and the European Clinical Trials Database (EudraCT number 2007-002693-66).. Between Sept 14, 2007, and Nov 17, 2009, we randomly assigned 16 071 evaluable patients to treatment: 8043 to odanacatib and 8028 to placebo. After a median follow-up of 36·5 months (IQR 34·43-40·15) 4297 women assigned to odanacatib and 3960 assigned to placebo enrolled in LOFT Extension (total median follow-up 47·6 months, IQR 35·45-60·06). In LOFT, cumulative incidence of primary outcomes for odanacatib versus placebo were: radiographic vertebral fractures 3·7% (251/6770) versus 7·8% (542/6910), hazard ratio (HR) 0·46, 95% CI 0·40-0·53; hip fractures 0·8% (65/8043) versus 1·6% (125/8028), 0·53, 0·39-0·71; non-vertebral fractures 5·1% (412/8043) versus 6·7% (541/8028), 0·77, 0·68-0·87; all p<0·0001. Combined results from LOFT plus LOFT Extension for cumulative incidence of primary outcomes for odanacatib versus placebo were: radiographic vertebral fractures 4·9% (341/6909) versus 9·6% (675/7011), HR 0·48, 95% CI 0·42-0·55; hip fractures 1·1% (86/8043) versus 2·0% (162/8028), 0·52, 0·40-0·67; non-vertebral fractures 6·4% (512/8043) versus 8·4% (675/8028), 0·74, 0·66-0·83; all p<0·0001. In LOFT, the composite cardiovascular endpoint of cardiovascular death, myocardial infarction, or stroke occurred in 273 (3·4%) of 8043 patients in the odanacatib group versus 245 (3·1%) of 8028 in the placebo group (HR 1·12, 95% CI 0·95-1·34; p=0·18). New-onset atrial fibrillation or flutter occurred in 112 (1·4%) of 8043 patients in the odanacatib group versus 96 (1·2%) of 8028 in the placebo group (HR 1·18, 0·90-1·55; p=0·24). Odanacatib was associated with an increased risk of stroke (1·7% [136/8043] vs 1·3% [104/8028], HR 1·32, 1·02-1·70; p=0·034), but not myocardial infarction (0·7% [60/8043] vs 0·9% [74/8028], HR 0·82, 0·58-1·15; p=0·26). The HR for all-cause mortality was 1·13 (5·0% [401/8043] vs 4·4% [356/8028], 0·98-1·30; p=0·10). When data from LOFT Extension were included, the composite of cardiovascular death, myocardial infarction, or stroke occurred in significantly more patients in the odanacatib group than in the placebo group (401 [5·0%] of 8043 vs 343 [4·3%] of 8028, HR 1·17, 1·02-1·36; p=0·029, as did stroke (2·3% [187/8043] vs 1·7% [137/8028], HR 1·37, 1·10-1·71; p=0·0051).. Odanacatib reduced the risk of fracture, but was associated with an increased risk of cardiovascular events, specifically stroke, in postmenopausal women with osteoporosis. Based on the overall balance between benefit and risk, the study's sponsor decided that they would no longer pursue development of odanacatib for treatment of osteoporosis.. Merck Sharp & Dohme Corp, a subsidiary of Merck & Co, Inc, Kenilworth, NJ, USA.

Topics: Aged; Aged, 80 and over; Biphenyl Compounds; Bone Density; Bone Density Conservation Agents; Double-Blind Method; Female; Fractures, Bone; Hip Fractures; Humans; Osteoporosis, Postmenopausal; Osteoporotic Fractures; Spinal Fractures; Treatment Outcome

Odanacatib is a cathepsin K inhibitor investigated for the treatment of postmenopausal osteoporosis. Phase 2 data indicate that 50 mg once weekly inhibits bone resorption and increases bone mineral density, with only a transient decrease in bone formation. We describe the background, design and participant characteristics for the phase 3 registration trial.. Odanacatib (ODN) is a selective cathepsin K inhibitor being evaluated for the treatment of osteoporosis. In a phase 2 trial, ODN 50 mg once weekly reduced bone resorption while preserving bone formation and progressively increased BMD over 5 years. We describe the phase III Long-Term ODN Fracture Trial (LOFT), an event-driven, randomized, blinded placebo-controlled trial, with preplanned interim analyses to permit early termination if significant fracture risk reduction was demonstrated. An extension was planned, with participants remaining on their randomized treatment for up to 5 years, then transitioning to open-label ODN.. The three primary outcomes were radiologically determined vertebral, hip, and clinical non-vertebral fractures. Secondary end points included clinical vertebral fractures, BMD, bone turnover markers, and safety and tolerability, including bone histology. Participants were women, 65 years or older, with a BMD T-score≤-2.5 at the total hip (TH) or femoral neck (FN) or with a prior radiographic vertebral fracture and a T-score≤-1.5 at the TH or FN. They were randomized to ODN or placebo tablets. All received weekly vitamin D3 (5600 international units (IU)) and daily calcium supplements as needed to ensure a daily intake of approximately 1200 mg.. Altogether, 16,713 participants were randomized at 387 centers. After a planned interim analysis, an independent data monitoring committee recommended that the study be stopped early due to robust efficacy and a favorable benefit/risk profile. Following the base study closeout, 8256 participants entered the study extension.. This report details the background and study design of this fracture end point trial and describes the baseline characteristics of its participants.

Topics: Aged; Biphenyl Compounds; Bone Density; Bone Density Conservation Agents; Cathepsin K; Double-Blind Method; Female; Femur Neck; Hip Joint; Humans; Osteoporosis, Postmenopausal; Osteoporotic Fractures; Patient Selection; Research Design; Treatment Outcome

The efficacy and safety of oral placebo or odanacatib 10, 25, or 50 mg once weekly for 52 weeks were evaluated in a double-blind, randomized, multi-center study in Japanese female and male patients with osteoporosis.. Odanacatib is a selective and reversible cathepsin K inhibitor that decreases bone resorption and increases bone mineral density (BMD).. The primary efficacy endpoint was percent change from baseline to week 52 in lumbar spine BMD. Secondary endpoints included percent change in total hip, femoral neck, and trochanter BMD and in bone biomarkers after treatment for 52 weeks.. In this study, 286 patients [94% female, mean age (SD) 68.2 (7.1) years] were included in the analysis. The least-squares mean percent changes from baseline to week 52 in the groups receiving placebo, 10, 25 and 50 mg of odanacatib for lumbar spine (L1~L4) BMD were 0.5, 4.1, 5.7, and 5.9% and for total hip BMD were -0.4, 1.3, 1.8, and 2.7%, respectively. The changes in femoral neck and trochanter BMD were similar to those at the total hip. Bone turnover markers were reduced in a dose-dependent manner. However, the effects of odanacatib on bone formation markers were less compared with the effects on bone resorption markers. Tolerability and safety profiles were similar among all treatment groups with no dose-related trends in any adverse events.. Weekly odanacatib treatment for 52 weeks increased BMD at the lumbar spine and at all hip sites in a dose-dependent manner and was well tolerated in Japanese patients with osteoporosis.

Topics: Aged; Anthropometry; Biomarkers; Biphenyl Compounds; Bone Density; Bone Density Conservation Agents; Cathepsin K; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Female; Hip Joint; Humans; Lumbar Vertebrae; Male; Middle Aged; Osteoporosis; Osteoporosis, Postmenopausal; Osteoporotic Fractures; Treatment Outcome

Case reports of women sustaining multiple vertebral fractures (VF) soon afterdenosumab discontinuation are accumulating.. We report a woman with five new vertebral fractures in ~8 months following discontinuation of long-term odanacatib (ODN), an experimental cathepsin K inhibitor.. DXA examination demonstrated an ~12% decline in bone mineral density (BMD) and ~9% decline in trabecular bone score (TBS) since ODN discontinuation. Laboratory evaluation did not reveal a secondary cause of bone loss.. This case mimics observations following denosumab discontinuation, but, to our knowledge, is the first reported with ODN and the first documenting substantial decline in TBS. While not directly clinically relevant as ODN is no longer being developed, this case raises the possibility that a syndrome of multiple vertebral fractures could follow discontinuation of various potent osteoporosis therapies that produce major BMD increases but do not have persisting bone effects (i.e., all non-bisphosphonates). Use of antiresorptive therapies to prevent rapid bone loss following discontinuation of potent bone active agents seems appropriate. Identification of those patients who could be at risk for the multiple VF syndrome is needed.

Topics: Aged; Biphenyl Compounds; Bone Density; Bone Density Conservation Agents; Drug Administration Schedule; Female; Humans; Osteoporosis, Postmenopausal; Osteoporotic Fractures; Radiography; Recurrence; Spinal Fractures; Withholding Treatment

Topics: Biphenyl Compounds; Bone and Bones; Cathepsin K; Female; Humans; Osteoporosis, Postmenopausal; Osteoporotic Fractures

Topics: Aged; Aged, 80 and over; Antibodies, Monoclonal, Humanized; Biphenyl Compounds; Bone Density Conservation Agents; Calcium, Dietary; Cause of Death; Combined Modality Therapy; Cross-Sectional Studies; Denosumab; Diphosphonates; Female; Germany; Humans; Life Style; Male; Middle Aged; Osteoporosis; Osteoporotic Fractures; Population Dynamics; Risk Factors; Selective Estrogen Receptor Modulators; Vitamin D

Topics: Adaptor Proteins, Signal Transducing; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Biphenyl Compounds; Bone Density Conservation Agents; Bone Morphogenetic Proteins; Cathepsin K; Denosumab; Diphosphonates; Drug Approval; Drugs, Investigational; Genetic Markers; Germany; Humans; Medication Adherence; Osteoporosis; Osteoporosis, Postmenopausal; Osteoporotic Fractures; RANK Ligand