Steve Deacon

Safety and Efficacy of the Cathepsin K Inhibitor ONO-5334 in Postmenopausal Osteoporosis: The OCEAN Study

Osteoporosis occurs when there is an imbalance between resorption and formation of bone, with resorption predominating. Inhibitors of cathepsin K may rebalance this condition. This is the first efficacy study of a new cathepsin K inhibitor, ONO‐5334. The objective of the study was to investigate the efficacy and safety of ONO‐5334 in postmenopausal osteoporosis. This was a 12‐month, randomized, double‐blind, placebo‐ and active‐controlled parallel‐group study conducted in 13 centers in 6 European countries. Subjects included 285 postmenopausal women aged 55 to 75 years with osteoporosis. Subjects were randomized into one of five treatment arms: placebo; 50 mg twice daily, 100 mg once daily, or 300 mg once daily of ONO‐5334; or alendronate 70 mg once weekly. Lumbar spine, total hip, and femoral neck BMD values were obtained along with biochemical markers of bone turnover and standard safety assessments. All ONO‐5334 doses and alendronate showed a significant increase in BMD for lumbar spine, total hip (except 100 mg once daily), and femoral neck BMD. There was little or no suppression of ONO‐5334 on bone‐formation markers compared with alendronate, although the suppressive effects on bone‐resorption markers were similar. There were no clinically relevant safety concerns. With a significant increase in BMD, ONO‐5334 also demonstrated a new mode of action as a potential agent for treating osteoporosis. Further clinical studies are warranted to investigate long‐term efficacy as well as safety of ONO‐5334.

Effect of ONO-5334 on bone mineral density and biochemical markers of bone turnover in postmenopausal osteoporosis: 2-year results from the OCEAN study.

Cathepsin K inhibitors, such as ONO‐5334, are being developed for the treatment of postmenopausal osteoporosis. However, their relative effects on bone resorption and formation, and how quickly the effects resolve after treatment cessation, are uncertain. The aim of this study was to examine the efficacy and safety of 24‐month treatment with ONO‐5334 and to assess the effect of treatment cessation over 2 months. We studied 197 postmenopausal women with osteoporosis or osteopenia with one fragility fracture. Patients were randomized to ONO‐5334 50 mg twice daily, 100 mg or 300 mg once daily, alendronate 70 mg once weekly (positive control), or placebo for 24 months. After 24 months, all ONO‐5334 doses were associated with increased bone mineral density (BMD) for lumbar spine, total hip, and femoral neck (p < 0.001). ONO‐5334 300 mg significantly suppressed the bone‐resorption markers urinary (u) NTX and serum and uCTX‐I throughout 24 months of treatment and to a similar extent as alendronate; other resorption marker levels remained similar to placebo (fDPD for ONO‐5334 300 mg qd) or were increased (ICTP, TRAP5b, all ONO‐5334 doses). Levels of B‐ALP and PINP were suppressed in all groups (including placebo) for approximately 6 months but then increased for ONO‐5334 to close to baseline levels by 12 to 24 months. On treatment cessation, there were increases above baseline in uCTX‐I, uNTX, and TRAP5b, and decreases in ICTP and fDPD. There were no clinically relevant safety concerns. Cathepsin K inhibition with ONO‐5334 resulted in decreases in most resorption markers over 2 years but did not decrease most bone formation markers. This was associated with an increase in BMD; the effect on biochemical markers was rapidly reversible on treatment cessation.

Pharmacodynamic Effects on Biochemical Markers of Bone Turnover and Pharmacokinetics of the Cathepsin K Inhibitor, ONO‐5334, in an Ascending Multiple‐Dose, Phase 1 Study

Selective inhibitors of cathepsin K, which has a major role in the degradation of bone collagen, are potential new treatments for osteoporosis. The pharmacokinetics and the pharmacodynamic effects on biochemical markers of bone turnover of the new cathepsin K inhibitor, ONO‐5334, were investigated in a multiple ascending dose, phase 1 study. A total of 120 healthy postmenopausal women were enrolled, and doses of 10 to 600 mg once daily and 50 and 300 mg twice daily were evaluated in 15‐ and 28‐day multiple‐dosing cohorts. Plasma ONO‐5334 concentration reached steady state within 2 days. Twenty‐four hours after the last dose in the 15‐day multiple‐dose cohort, 100, 300, and 600 mg once daily reduced urinary C‐terminal telopeptide of type I collagen by a mean (± standard deviation) 44.9% ± 13.6%, 84.5% ± 4.4%, and 92.5% ± 1.3%, respectively. The 28‐day cohort showed similar effects. There were far smaller effects on bone‐specific alkaline phosphatase (B‐ALP), tartrate‐resistant acid phosphatase 5b (TRAP5b), or osteocalcin (OC) (measured after 28 days). ONO‐5334 was well tolerated up to 600 mg/d and for up to 28 days of multiple dosing. Multiple dosing with ONO‐5334 100 mg resulted in considerable suppression of bone resorption markers with no appreciable effects on bone formation markers (B‐ALP, OC) or osteoclast number (TRAP5b).

Serum and urine bone resorption markers and pharmacokinetics of the cathepsin K inhibitor ONO‐5334 after ascending single doses in post menopausal women

AIMS To investigate the safety, pharmacokinetics and pharmacodynamics of the new cathepsin K inhibitor, ONO-5334. METHODS A double-blind, placebo-controlled, randomized study was carried out in 52 healthy post menopausal females. Single ascending doses of ONO-5334 (3-600 mg) were evaluated in six cohorts. The effect of food was studied at ONO-5334 100 mg. RESULTS Across the doses tested, mean ONO-5334 C(max) occurred 0.5-1.0 h after dosing and the the t(1/2) ranged from 9.1 to 22 h. Linear increases in C(max) and AUC(0,∞) were observed in the 3-300 mg and 3-600 mg dose range, respectively. After food, the geometric mean ratio (95% CI) C(max) and AUC(0,∞) for ONO-5334 were 0.78 (0.31, 1.94) and 0.95 (0.67, 1.35)-fold greater than fasted, respectively. ONO-5334 significantly reduced serum bone resorption markers within 4 h vs. placebo. Statistical significance was achieved for ONO-5334 doses ≥30 mg for C-terminal telopeptide of type 1 collagen (CTX) and ≥300 mg for N-terminal telopeptide of type 1 collagen (NTX). Statistical significance was still evident at 24 h for ONO-5334 100 mg with serum CTX and 600 mg with serum NTX. The maximum suppression in serum CTX occurred at 4 h post dose with difference compared with placebo of -32%, -59%, -60% and -66% for 30, 100, 300 and 600 mg ONO-5334, respectively. Second morning urine void 24 h post dose showed statistically significant suppression of urinary CTX and NTX at 100 mg and above vs. placebo. ONO-5334 600 mg showed statistically significant suppression up to 72 h for serum CTX, urinary CTX and urinary NTX and 48 h for serum NTX vs. placebo. Adverse events were transient with no evidence of dose relationship. CONCLUSIONS ONO-5334 displayed linear plasma pharmacokinetics over the (predicted therapeutic) dose range, 3-300 mg, with clear suppression of urinary bone resorption markers at doses ≥100 mg for serum markers at 24 h. ONO-5334 was well tolerated up to 600 mg day(-1) when administered to healthy post menopausal women.

Effects of 16-month treatment with the cathepsin K inhibitor ONO-5334 on bone markers, mineral density, strength and histomorphometry in ovariectomized cynomolgus monkeys

We examined the effects of ONO-5334, a cathepsin K inhibitor, on bone markers, BMD, strength and histomorphometry in ovariectomized (OVX) cynomolgus monkeys. ONO-5334 (1.2, 6 and 30mg/kg/day, p.o.), alendronate (0.05mg/kg/2weeks, i.v.), or vehicle was administered to OVX monkeys (all groups N=20) for 16months. A concurrent Sham group (N=20) was also treated with vehicle for 16months. OVX significantly increased bone resorption and formation markers and decreased BMD in lumbar vertebra, femoral neck, proximal tibia and distal radius. Alendronate suppressed these parameters to a level similar to that in the Sham-operated monkeys. ONO-5334 at doses 6 and 30mg/kg decreased bone resorption markers to a level roughly half of that in the Sham group, while keeping bone formation markers level above that in the Sham monkeys. Changes in DXA BMD confirmed that ONO-5334 at doses 6 and 30mg/kg increased BMD to a level greater than that in the Sham group in all examined sites. In the proximal tibia, in vivo pQCT analysis showed that ONO-5334 at doses 6 and 30mg/kg suppressed trabecular BMD loss to the sham level. However, ONO-5334 increased cortical BMD, cortical area and cortical thickness to a level greater than that in the Sham group, suggesting that ONO-5334 improves both cortical BMD and cortical geometry. Histomorphometric analysis revealed that ONO-5334 suppressed bone formation rate (BFR) at osteonal site in the midshaft femur but did not influence OVX-induced increase in BFR at either the periosteal or endocortical surfaces. Unlike alendronate, ONO-5334 increased osteoclasts surface (Oc.S/BS) and serum tartrate-resistant acid phosphatise 5b (TRAP5b) activity, highlighting the difference in the mode of action between these two drugs. Our results suggest that ONO-5334 has therapeutic potential not only in vertebral bones, but also in non-vertebral bones.

Modeling and simulation of bone mineral density response from a phase 2 study of ONO-5334, a new cathepsin K inhibitor, to support dose selection in osteoporosis.

ONO‐5334, a selective inhibitor of cathepsin K, is a potential new treatment for osteoporosis. The objectives of this modeling study were to (1) develop exposure–response (E–R) models to relate ONO‐5334 exposure to bone mineral density (BMD), (2) predict BMD responses to various doses of ONO‐5334 for both immediate release tablet (IRT) and sustained release tablet (SRT) formulations where only BMD response after administration of IRT had been studied to date, (3) inform selection of appropriate formulation/dose using simulation for future clinical trials. A population pharmacokinetic (PK) model was developed to simultaneously analyze data for both IRT and SRT. The exposure metrics at steady state were estimated by post hoc Bayesian prediction using the final population PK model. E–R models were developed using dose‐ranging data with only IRT from postmenopausal females with osteoporosis. Based on the developed model, lumbar spine and total hip BMD after administration of ONO‐5334 SRT as well as IRT were simulated. The simulation results showed that ONO‐5334 SRT should provide comparable BMD responses at a lower dose relative to IRT (a finding consistent with the results from a previous population PK–PD modeling study with bone resorption markers).

Population pharmacokinetic and pharmacodynamic modeling of different formulations of ONO-5334, cathepsin K inhibitor, in Caucasian and Japanese postmenopausal females.

ONO‐5334, a selective inhibitor of cathepsin K, is a potential new treatment for osteoporosis. The objectives of this study were to (1) develop population pharmacokinetic–pharmacodynamic (PK–PD) models for ONO‐5334 using dose‐ascending data from healthy postmenopausal females, (2) examine comparability of PK and/or PD profile between Caucasian and Japanese, and (3) compare PK–PD profile between immediate release tablet (IRT) and sustained release tablet (SRT). The population PK–PD models were developed for each formulation for post‐dose levels of bone resorption markers (serum CTX and NTX). The data were provided from 4 phase 1 studies with total of 201 Caucasian and 94 Japanese subjects. Plasma concentrations of ONO‐5334 and bone resorption markers were thoroughly evaluated in those studies. An indirect response model described relationships between bone resorption markers and plasma concentrations of ONO‐5334. There was no significant difference in PK and pharmacodynamic potency (IC50) between Caucasian and Japanese. Based on the developed model, serum CTX and NTX after administration of ONO‐5334 IRT or SRT were simulated, and the results showed that ONO‐5334 SRT would provide comparable PD effect on bone resorption markers with lower dose relative to IRT.

Effects of novel cathepsin K inhibitor ONO-5334 on bone resorption markers: a study of four sustained release formulations with different pharmacokinetic patterns

The purpose of the study was clarify the effect of the cathepsin K inhibitor ONO-5334 on bone resortion markers using sustained release (SR) formulations with different pharmacokinetic (PK) patterns, and identify the optimal SR formulation. The PK profiles and pharmacodynamic effect on bone resorption markers of 4 SR candidates formulations were evaluated in healthy postmenopausal women within a randomized, 2-part, open-label crossover study. In Part A, subject received a single dose of each formulation orally in the fed state. In Part B, two selected formulations were evaluated in the fasted state. From the results from Part A, Cmax was reduced and plasma concentrations of ONO-5334 were sustained with all SR formulations compared with an immediate release tablet. In pharmacodynamics, the level of C-terminal telopeptide of type I collagen (CTX) in serum and urine were inhibited with SR tablets rather than with granules. Cmax and area under the concentration–time curve from time 0 to the last measurable time point (AUC0−t) of SR tablets were higher than those of granules. From Part B, Cmax in the fasted condition was lower than that in the fed condition with two SR tablets. In contrast, C24 h in the fasted condition was slightly higher than that in the fed condition, but AUC0−t was similar. The inhibitory effect on CTX in serum and urine may depend on the PK pattern of ONO-5334. The SR tablets was well tolerated in postmenopausal women and has the optimal SR profiles on pharmacodynamics effect on bone resortion markers and PK profile. These results suggest that SR tablets of ONO-5334 are an excellent drug candidate for osteoporosis.

Effect of ONO-5334 on Bone Mineral Density and Biochemical Markers of Bone Turnover in Postmenopausal Osteoporosis: 2-Year Results From the OCEAN Study: 2-YEAR TREATMENT OF OSTEOPOROSIS WITH ONO-5334

Cathepsin K inhibitors, such as ONO‐5334, are being developed for the treatment of postmenopausal osteoporosis. However, their relative effects on bone resorption and formation, and how quickly the effects resolve after treatment cessation, are uncertain. The aim of this study was to examine the efficacy and safety of 24‐month treatment with ONO‐5334 and to assess the effect of treatment cessation over 2 months. We studied 197 postmenopausal women with osteoporosis or osteopenia with one fragility fracture. Patients were randomized to ONO‐5334 50 mg twice daily, 100 mg or 300 mg once daily, alendronate 70 mg once weekly (positive control), or placebo for 24 months. After 24 months, all ONO‐5334 doses were associated with increased bone mineral density (BMD) for lumbar spine, total hip, and femoral neck (p < 0.001). ONO‐5334 300 mg significantly suppressed the bone‐resorption markers urinary (u) NTX and serum and uCTX‐I throughout 24 months of treatment and to a similar extent as alendronate; other resorption marker levels remained similar to placebo (fDPD for ONO‐5334 300 mg qd) or were increased (ICTP, TRAP5b, all ONO‐5334 doses). Levels of B‐ALP and PINP were suppressed in all groups (including placebo) for approximately 6 months but then increased for ONO‐5334 to close to baseline levels by 12 to 24 months. On treatment cessation, there were increases above baseline in uCTX‐I, uNTX, and TRAP5b, and decreases in ICTP and fDPD. There were no clinically relevant safety concerns. Cathepsin K inhibition with ONO‐5334 resulted in decreases in most resorption markers over 2 years but did not decrease most bone formation markers. This was associated with an increase in BMD; the effect on biochemical markers was rapidly reversible on treatment cessation.

Effect of ONO-5334 on Bone Mineral Density and Biochemical Markers of Bone Turnover in Postmenopausal Osteoporosis

Cathepsin K inhibitors, such as ONO‐5334, are being developed for the treatment of postmenopausal osteoporosis. However, their relative effects on bone resorption and formation, and how quickly the effects resolve after treatment cessation, are uncertain. The aim of this study was to examine the efficacy and safety of 24‐month treatment with ONO‐5334 and to assess the effect of treatment cessation over 2 months. We studied 197 postmenopausal women with osteoporosis or osteopenia with one fragility fracture. Patients were randomized to ONO‐5334 50 mg twice daily, 100 mg or 300 mg once daily, alendronate 70 mg once weekly (positive control), or placebo for 24 months. After 24 months, all ONO‐5334 doses were associated with increased bone mineral density (BMD) for lumbar spine, total hip, and femoral neck (p < 0.001). ONO‐5334 300 mg significantly suppressed the bone‐resorption markers urinary (u) NTX and serum and uCTX‐I throughout 24 months of treatment and to a similar extent as alendronate; other resorption marker levels remained similar to placebo (fDPD for ONO‐5334 300 mg qd) or were increased (ICTP, TRAP5b, all ONO‐5334 doses). Levels of B‐ALP and PINP were suppressed in all groups (including placebo) for approximately 6 months but then increased for ONO‐5334 to close to baseline levels by 12 to 24 months. On treatment cessation, there were increases above baseline in uCTX‐I, uNTX, and TRAP5b, and decreases in ICTP and fDPD. There were no clinically relevant safety concerns. Cathepsin K inhibition with ONO‐5334 resulted in decreases in most resorption markers over 2 years but did not decrease most bone formation markers. This was associated with an increase in BMD; the effect on biochemical markers was rapidly reversible on treatment cessation.