CCR5 Receptor Occupancy Analysis Reveals Increased Peripheral Blood CCR5+CD4+ T Cells Following Treatment With the Anti-CCR5 Antibody Leronlimab.

CCR5 plays a central role in infectious disease, host defense, and cancer progression, thereby making it an ideal target for therapeutic development. Notably, CCR5 is the major HIV entry co-receptor, where its surface density correlates with HIV plasma viremia. The level of CCR5 receptor occupancy (RO) achieved by a CCR5-targeting therapeutic is therefore a critical predictor of its efficacy. However, current methods to measure CCR5 RO lack sensitivity, resulting in high background and overcalculation. Here, we report on two independent, flow cytometric methods of calculating CCR5 RO using the anti-CCR5 antibody, Leronlimab. We show that both methods led to comparable CCR5 RO values, with low background on untreated CCR5+CD4+ T cells and sensitive measurements of occupancy on both blood and tissue-resident CD4+ T cells that correlated longitudinally with plasma concentrations in Leronlimab-treated macaques. Using these assays, we found that Leronlimab stabilized cell surface CCR5, leading to an increase in the levels of circulating and tissue-resident CCR5+CD4+ T cells in vivo in Leronlimab-treated macaques. Weekly Leronlimab treatment in a chronically SIV-infected macaque led to increased CCR5+CD4+ T cells levels and fully suppressed plasma viremia, both concomitant with full CCR5 RO on peripheral blood CD4+ T cells, demonstrating that CCR5+CD4+ T cells were protected from viral replication by Leronlimab binding. Finally, we extended these results to Leronlimab-treated humans and found that weekly 700 mg Leronlimab led to complete CCR5 RO on peripheral blood CD4+ T cells and a statistically significant increase in CCR5+CD4+ T cells in peripheral blood. Collectively, these results establish two RO calculation methods for longitudinal monitoring of anti-CCR5 therapeutic antibody blockade efficacy in both macaques and humans, demonstrate that CCR5+CD4+ T cell levels temporarily increase with Leronlimab treatment, and facilitate future detailed investigations into the immunological impacts of CCR5 inhibition in multiple pathophysiological processes.

Functional risk for fracture by safe functional motion testing: a short version of the safe functional motion test.

BACKGROUND: 'Unsafe' movement strategies used to perform everyday activities were quantified using scores for tasks included in the Short Form Safe Functional Motion test series (SSFM). Baseline scores were independently associated with incident fractures after adjusting for factors known to effect fracture risk. The purpose of the present study is to determine whether the SSFM, a series of tests of habitual motion, is associated with incident fragility fracture at any skeletal sites. METHODS: An osteoporosis clinic database was queried for adults with baseline SSFM scores and corresponding data for prevalent fractures, femoral neck bone mineral density (fnBMD), osteoporosis medication use, and incident fractures at 1-year and 3-year follow ups [n = 1700 (118 incident fractures) and n = 1058 (202 incident fractures), respectively]. Multiple logistic regressions, adjusted for sex, age, fnBMD, osteoporosis medication use, and any prevalent fractures at baseline, were used to determine whether baseline SSFM scores were associated with incident fragility fractures. RESULTS: An Sfm-3 score was a significant independent predictor of any fracture at 1 year [adjusted odds ratio (95% CI) = 1.118 (1.025, 1.219) for each 10-point decrease in Sfm-3; p = 0.012], and 3-year follow up [adjusted odds ratio (95% CI) = 1.183 (1.098, 1.274) for each 10-point decrease in Sfm-3; p < 0.0001]. CONCLUSIONS: Scores on the SSFM predict fracture risk such that for each 10-point drop in score the odds of fracture are increased by up to 18% independent of risk associated with age, bone mineral density, use of bone-sparing medications, and history of a fracture.

Remodeling- and Modeling-Based Bone Formation With Teriparatide Versus Denosumab: A Longitudinal Analysis From Baseline to 3 Months in the AVA Study.

There has been renewed interest of late in the role of modeling-based formation (MBF) during osteoporosis therapy. Here we describe early effects of an established anabolic (teriparatide) versus antiresorptive (denosumab) agent on remodeling-based formation (RBF), MBF, and overflow MBF (oMBF) in human transiliac bone biopsies. Postmenopausal women with osteoporosis received subcutaneous teriparatide (n = 33, 20 µg/d) or denosumab (n = 36, 60 mg once/6 months), open-label for 6 months at 7 US and Canadian sites. Subjects received double fluorochrome labeling at baseline and before biopsy at 3 months. Sites of bone formation were designated as MBF if the underlying cement line was smooth, RBF if scalloped, and oMBF if formed over smooth cement lines adjacent to scalloped reversal lines. At baseline, mean RBF/bone surface (BS), MBF/BS, and oMBF/BS were similar between the teriparatide and denosumab groups in each bone envelope assessed (cancellous, endocortical, periosteal). All types of formation significantly increased from baseline in the cancellous and endocortical envelopes (differences p < 0.001) with teriparatide (range of changes 2.9- to 21.9-fold), as did MBF in the periosteum (p < 0.001). In contrast, all types of formation were decreased or not significantly changed with denosumab, except MBF/BS in the cancellous envelope, which increased 2.5-fold (difference p = 0.048). These data highlight mechanistic differences between these agents: all 3 types of bone formation increased significantly with teriparatide, whereas formation was predominantly decreased or not significantly changed with denosumab, except for a slight increase in MBF/BS in the cancellous envelope. © 2017 American Society for Bone and Mineral Research.

Differential Effects of Teriparatide and Denosumab on Intact PTH and Bone Formation Indices: AVA Osteoporosis Study.

We compared effects of teriparatide and denosumab on PTH, bone turnover markers, and bone histomorphometry in osteoporotic postmenopausal women. The findings were inconsistent with an early indirect anabolic effect of denosumab.

A Longitudinal Study of Skeletal Histomorphometry at 6 and 24 Months Across Four Bone Envelopes in Postmenopausal Women With Osteoporosis Receiving Teriparatide or Zoledronic Acid in the SHOTZ Trial.

Previously, we reported the effects of teriparatide (TPTD) and zoledronic acid (ZOL) on bone formation based on biochemical markers and bone histomorphometry of the cancellous envelope at month 6 in postmenopausal women with osteoporosis who participated in the 12-month primary Skeletal Histomorphometry in Subjects on Teriparatide or Zoledronic Acid Therapy (SHOTZ) study. Patients were eligible to enter a 12-month extension on their original treatment regimen: TPTD 20 µg/day (s.c. injection) or ZOL 5 mg/year (i.v. infusion). A second biopsy was performed at month 24. Here we report longitudinal changes between and within each treatment group in the cancellous, endocortical, intracortical, and periosteal bone envelopes in patients with evaluable biopsies at months 6 and 24 (paired data set: TPTD, n = 10; ZOL, n = 9). Between-group differences are also reported in the larger set of patients with evaluable biopsies at month 6 (TPTD, n = 28; ZOL, n = 30). Data from the cancellous envelope at month 6 or month 24 provided a reference to compare differences across envelopes within each treatment group. The 24-month results extend our earlier report that TPTD and ZOL possess different tissue-level mechanisms of action. Moreover, these differences persisted for at least 2 years in all four bone envelopes. Few longitudinal differences were observed within or across bone envelopes in ZOL-treated patients, suggesting that the low bone formation indices at month 6 persisted to month 24. Conversely, the magnitude of the effect of TPTD on bone formation varied across individual envelopes: median values for mineralizing surface (MS/BS) and bone formation rate (BFR/BS) at month 6 were approximately 3-fold to 5-fold higher in the endocortical and intracortical envelopes compared to the cancellous envelope. Although MS/BS and BFR/BS declined in these envelopes at month 24, median values continued to exceed, or were not significantly different from, those in the cancellous envelope. This study demonstrates for the first time that bone formation indices are higher with TPTD treatment than with ZOL in all four bone envelopes and the difference persists for at least 2 years. Moreover, the magnitude of the effect of TPTD in cortical bone remains robust at 24 months. © 2016 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research (ASBMR).

Myostatin antibody (LY2495655) in older weak fallers: a proof-of-concept, randomised, phase 2 trial.

BACKGROUND: Myostatin inhibits skeletal muscle growth. The humanised monoclonal antibody LY2495655 (LY) binds and neutralises myostatin. We aimed to test whether LY increases appendicular lean body mass (aLBM) and improves physical performance in older individuals who have had recent falls and low muscle strength and power. METHODS: In this proof-of-concept, randomised, placebo-controlled, double-blind, parallel, multicentre, phase 2 study, we recruited patients aged 75 years or older who had fallen in the past year from 21 investigator sites across Argentina, Australia, France, Germany, Sweden, and the USA. Eligible patients had low performance on hand grip strength and chair rise tests, tested with the procedure described by Guralnik and colleagues. Participants were stratified by country, age, hand grip strength, and performance on the chair rise test, and were randomly assigned (1:1) by a computer-generated random sequence to receive subcutaneous injections of placebo or 315 mg LY at weeks 0 (randomisation visit), 4, 8, 12, 16, and 20, followed by 16 weeks observation. The primary outcome was change in aLBM from baseline to 24 weeks. We measured physical performance as secondary outcomes (four-step stair climbing time, usual gait speed, and time to rise five times from a chair without arms, or with arms for participants unable to do it without arms) and exploratory outcomes (12-step stair climbing test, 6-min walking distance, fast gait speed, hand grip strength, and isometric leg extension strength). Efficacy analyses included all randomly assigned patients who received at least one dose and had a baseline and at least one subsequent measure. The primary analysis and all other tests of treatment effect (except physical performance tests) were done at a two-sided alpha level of 0·05. Tests of treatment effect on physical performance tests were done at a pre-specified two-sided alpha level of 0·1. This trial is registered with ClinicalTrials.gov, number NCT01604408. FINDINGS: Between June 19, 2012, and Dec 12, 2013, we screened 365 patients. 99 were randomly assigned to receive placebo and 102 to receive LY. Treatment was completed in 85 (86%) of patients given placebo and in 82 (80%) given LY. At 24 weeks, the least-squares mean change in aLBM was -0·123 kg (95% CI -0·287 to 0·040) in the placebo group and 0·303 kg (0·135 to 0·470) in the LY group, a difference of 0·43 kg (95% CI 0·192 to 0·660; p<0·0001). Stair climbing time (four-step and 12-step tests), chair rise with arms, and fast gait speed improved significantly from baseline to week 24 with differences between LY and placebo of respectively -0·46 s (p=0·093), -1·28 s (p=0·011), -4·15 s (p=0·054), and 0·05 m/s (p=0·088). No effect was detected for other performance-based measures. Injection site reactions were recorded in nine (9%) patients given placebo and in 31 (30%) patients given LY (p<0·0001), and were generally mild, and led to treatment discontinuation in two patients given LY. INTERPRETATION: Our findings show LY treatment increases lean mass and might improve functional measures of muscle power. Although additional studies are needed to confirm these results, our data suggest LY should be tested for its potential ability to reduce the risk of falls or physical dependency in older weak fallers. FUNDING: Eli Lilly and Company.

The Effect of Discontinuing Treatment With Blosozumab: Follow-up Results of a Phase 2 Randomized Clinical Trial in Postmenopausal Women With Low Bone Mineral Density.

Administration of blosozumab, a humanized monoclonal antibody that binds sclerostin, increases bone formation and bone mineral density (BMD) in postmenopausal women with low BMD. To evaluate the effect of discontinuing blosozumab, we studied women enrolled in a 1-year randomized, placebo-controlled phase 2 trial for an additional year after they completed treatment. Of the 120 women initially enrolled in the study, 106 women completed treatment and continued into follow-up; 88 women completed 1 year of follow-up. At the beginning of follow-up, groups remained balanced for age, race, and body mass index, but lumbar spine and total hip BMD were increased in prior blosozumab groups, reflecting an anabolic treatment effect. At the end of follow-up, 1 year after discontinuing treatment, lumbar spine BMD remained significantly greater than placebo in women initially treated with blosozumab 270 mg every 2 weeks (Q2W) and blosozumab 180 mg Q2W (6.9% and 3.6% above baseline, respectively). Total hip BMD also declined after discontinuation of treatment but at 1 year after treatment remained significantly greater than placebo in women initially treated with blosozumab 270 mg Q2W and blosozumab 180 mg Q2W (3.9% and 2.6% above baseline, respectively). During follow-up, median serum P1NP was not consistently different between the prior blosozumab groups and placebo. A similar pattern was apparent for median serum C-terminal telopeptide of type 1 collagen (CTx) levels, with more variability. Mean serum total sclerostin concentration increased with blosozumab, indicating target engagement, and declined to baseline after discontinuation. There were no adverse events considered related to prior treatment with blosozumab. Anti-drug antibodies generally declined in patients who had detectable levels during prior treatment. These findings support the continued study of blosozumab as an anabolic therapy for treatment of osteoporosis.

Skeletal histomorphometry in subjects on teriparatide or zoledronic acid therapy (SHOTZ) study: a randomized controlled trial.

CONTEXT: Recent studies on the mechanism of action (MOA) of bone-active drugs have rekindled interest in how to present and interpret dynamic histomorphometric parameters of bone remodeling. OBJECTIVE: We compared the effects of an established anabolic agent, teriparatide (TPTD), with those of a prototypical antiresorptive agent, zoledronic acid (ZOL). DESIGN: This was a 12-month, randomized, double-blind, active-comparator controlled, cross-sectional biopsy study. SETTING: The study was conducted at 12 U.S. and Canadian centers. SUBJECTS: Healthy postmenopausal women with osteoporosis participated in the study. INTERVENTIONS: Subjects received TPTD 20 µg once daily by sc injection (n = 34) or ZOL 5 mg by iv infusion at baseline (n = 35). MAIN OUTCOME MEASURES: The primary end point was mineralizing surface/bone surface (MS/BS), a dynamic measure of bone formation, at month 6. A standard panel of dynamic and static histomorphometric indices was also assessed. When specimens with missing labels were encountered, several methods were used to calculate mineral apposition rate (MAR). Serum markers of bone turnover were also measured. RESULTS: Among 58 subjects with evaluable biopsies (TPTD = 28; ZOL = 30), MS/BS was significantly higher in the TPTD group (median: 5.60 vs. 0.16%, P < 0.001). Other bone formation indices, including MAR, were also higher in the TPTD group (P < 0.05). TPTD significantly increased procollagen type 1 N-terminal propeptide (PINP) at months 1, 3, 6, and 12 and carboxyterminal cross-linking telopeptide of collagen type 1 (CTX) from months 3 to 12. ZOL significantly decreased PINP and CTX below baseline at all time points. CONCLUSIONS: TPTD and ZOL possess fundamentally different mechanisms of action with opposite effects on bone formation based on this analysis of both histomorphometric data and serum markers of bone formation and resorption. An important mechanistic difference was a substantially higher MS/BS in the TPTD group. Overall, these results define the dynamic histomorphometric characteristics of anabolic activity relative to antiresorptive activity after treatment with these two drugs.

Teriparatide for acceleration of fracture repair in humans: a prospective, randomized, double-blind study of 102 postmenopausal women with distal radial fractures.

Animal experiments show a dramatic improvement in skeletal repair by teriparatide. We tested the hypothesis that recombinant teriparatide, at the 20 microg dose normally used for osteoporosis treatment or higher, would accelerate fracture repair in humans. Postmenopausal women (45 to 85 years of age) who had sustained a dorsally angulated distal radial fracture in need of closed reduction but no surgery were randomly assigned to 8 weeks of once-daily injections of placebo (n = 34) or teriparatide 20 microg (n = 34) or teriparatide 40 microg (n = 34) within 10 days of fracture. Hypotheses were tested sequentially, beginning with the teriparatide 40 microg versus placebo comparison, using a gatekeeping strategy. The estimated median time from fracture to first radiographic evidence of complete cortical bridging in three of four cortices was 9.1, 7.4, and 8.8 weeks for placebo and teriparatide 20 microg and 40 microg, respectively (overall p = .015). There was no significant difference between the teriparatide 40 microg versus placebo groups (p = .523). In post hoc analyses, there was no significant difference between teriparatide 40 microg versus 20 microg (p = .053); however, the time to healing was shorter in teriparatide 20 microg than placebo (p = .006). The primary hypothesis that teriparatide 40 microg would shorten the time to cortical bridging was not supported. The shortened time to healing for teriparatide 20 microg compared with placebo still may suggest that fracture repair can be accelerated by teriparatide, but this result should be interpreted with caution and warrants further study.

Incidence of osteonecrosis of the jaw in women with postmenopausal osteoporosis in the health outcomes and reduced incidence with zoledronic acid once yearly pivotal fracture trial.

BACKGROUND: The authors determined incidence of osteonecrosis of the jaw (ONJ) in a large, prospective three-year clinical trial of zoledronic acid in women with postmenopausal osteoporosis (PMO). METHODS: A total of 7,714 women with PMO received intravenous zoledronic acid 5 mg or a placebo. No spontaneous reports of ONJ were received. An independent, blinded adjudication committee searched the trial's adverse event database by using 60 terms. On an ongoing basis, the committee reviewed the identified events, and it defined ONJ as exposed bone in the maxillofacial area with delayed healing for more than six weeks despite appropriate care. RESULTS: One participant who received a placebo and one participant who received zoledronic acid experienced delayed healing associated with infection. Both conditions resolved after antibiotic therapy, débridement or both. CONCLUSION: The occurrence of ONJ is rare in a PMO population, and delayed healing of lesions can occur with and without bisphosphonate use over three years. CLINICAL IMPLICATIONS: The low incidence of ONJ must be assessed in the context of the clinical benefit of zoledronic acid therapy in reducing hip, vertebral and nonvertebral fractures in this at-risk population. There is no evidence to suggest that healthy patients with osteoporosis who are receiving bisphosphonates require any special treatment beyond routine dental care or to support altering standard treatment practices.

Comparative effects of raloxifene and alendronate on fracture outcomes in postmenopausal women with low bone mass.

UNLABELLED: The double-blind, randomized raloxifene alendronate comparison trial was the first study designed to compare two osteoporosis therapies head-to-head for fracture risk reduction. The original protocol planned to treat 3000 postmenopausal women with alendronate 10 mg/day (ALN) or raloxifene 60 mg/day (RLX) for 5 years, and to recruit women (50-80 years old) with a femoral neck bone mineral density (BMD) T-score between -2.5 and -4.0, inclusive, no prevalent vertebral fractures, and no prior bone-active agent use. The trial was stopped early, due to difficulty in finding treatment-naïve women to meet enrollment goals within the planned timeline, resulting in insufficient power to show non-inferiority between therapies in the primary endpoint (number of women with >or=1 new osteoporotic vertebral or nonvertebral fracture). Except for vertebral fractures, fracture analyses were based upon 1412 of the 1423 women randomized (mean age of 66 years). After 312+/-254 days (mean+/-SD), 22 women in the ALN group and 20 in the RLX group had new vertebral or nonvertebral fractures. Four women in the ALN group and none in the RLX group had moderate/severe vertebral fractures, a pre-specified endpoint (P=0.04). Lumbar spine, femoral neck, and total hip BMD were increased from baseline at 2 years in each group (P<0.001), with greater increases in the ALN group (each P<0.05). Similar numbers of women in each group had >or=1 adverse event and discontinued due to an adverse event. The only adverse events with an incidence that differed between groups were colonoscopy, diarrhea, and nausea; each was more common with ALN treatment (each P<0.05). One woman in each group had a venous thromboembolic event. One case of breast cancer occurred in each group. In summary, as this trial was terminated early, there was insufficient power to compare the fracture risks between alendronate and raloxifene. Safety profiles were as expected from clinical trial and post-marketing reports. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT00035971.