Evaluation of a stabilized RSV pre-fusion F mRNA vaccine: Preclinical studies and Phase 1 clinical testing in healthy adults.

Human respiratory syncytial virus (RSV) causes a substantial proportion of respiratory tract infections worldwide. Although RSV reinfections occur throughout life, older adults, particularly those with underlying comorbidities, are at risk for severe complications from RSV. There is no RSV vaccine available to date, and treatment of RSV in adults is largely supportive. A correlate of protection for RSV has not yet been established, but antibodies targeting the pre-fusion conformation of the RSV F glycoprotein play an important role in RSV neutralization. We previously reported a Phase 1 study of an mRNA-based vaccine (V171) expressing a pre-fusion-stabilized RSV F protein (mDS-Cav1) in healthy adults. Here, we evaluated an mRNA-based vaccine (V172) expressing a further stabilized RSV pre-fusion F protein (mVRC1). mVRC1 is a single chain version of RSV F with interprotomer disulfides in addition to the stabilizing mutations present in the mDS-Cav1 antigen. The immunogenicity of the two mRNA-based vaccines encoding mVRC1 (V172) or a sequence-optimized version of mDS-Cav1 to improve transcriptional fidelity (V171.2) were compared in RSV-naïve and RSV-experienced African green monkeys (AGMs). V172 induced higher neutralizing antibody titers than V171.2 and demonstrated protection in the AGM challenge model. We conducted a Phase 1, randomized, placebo-controlled, clinical trial of 25 µg, 100 µg, 200 µg, or 300 µg of V172 in healthy older adults (60-79 years old; N = 112) and 100 µg, 200 µg, or 300 µg of V172 in healthy younger adults (18-49 years old; N = 48). The primary clinical objectives were to evaluate the safety and tolerability of V172, and the secondary objective was to evaluate RSV serum neutralization titers. The most commonly reported solicited adverse events were injection-site pain, injection-site swelling, headache, and tiredness. V172 was generally well tolerated in older and younger adults and increased serum neutralizing antibody titers, pre-fusion F-specific competing antibody titers, and RSV F-specific T-cell responses.

Orally Bioavailable Macrocyclic Peptide That Inhibits Binding of PCSK9 to the Low Density Lipoprotein Receptor.

BACKGROUND: Inhibition of PCSK9 (proprotein convertase subtilisin/kexin type 9)-low density lipoprotein receptor interaction with injectable monoclonal antibodies or small interfering RNA lowers plasma low density lipoprotein-cholesterol, but despite nearly 2 decades of effort, an oral inhibitor of PCSK9 is not available. Macrocyclic peptides represent a novel approach to target proteins traditionally considered intractable to small-molecule drug design. METHODS: Novel mRNA display screening technology was used to identify lead chemical matter, which was then optimized by applying structure-based drug design enabled by novel synthetic chemistry to identify macrocyclic peptide (MK-0616) with exquisite potency and selectivity for PCSK9. Following completion of nonclinical safety studies, MK-0616 was administered to healthy adult participants in a single rising-dose Phase 1 clinical trial designed to evaluate its safety, pharmacokinetics, and pharmacodynamics. In a multiple-dose trial in participants taking statins, MK-0616 was administered once daily for 14 days to characterize the safety, pharmacokinetics, and pharmacodynamics (change in low density lipoprotein cholesterol). RESULTS: MK-0616 displayed high affinity (Ki = 5pM) for PCSK9 in vitro and sufficient safety and oral bioavailability preclinically to enable advancement into the clinic. In Phase 1 clinical studies in healthy adults, single oral doses of MK-0616 were associated with >93% geometric mean reduction (95% CI, 84-103) of free, unbound plasma PCSK9; in participants on statin therapy, multiple-oral-dose regimens provided a maximum 61% geometric mean reduction (95% CI, 43-85) in low density lipoprotein cholesterol from baseline after 14 days of once-daily dosing of 20 mg MK-0616. CONCLUSIONS: This work validates the use of mRNA display technology for identification of novel oral therapeutic agents, exemplified by the identification of an oral PCSK9 inhibitor, which has the potential to be a highly effective cholesterol lowering therapy for patients in need.

Effects of an inhaled soluble guanylate cyclase (sGC) stimulator MK-5475 in pulmonary arterial hypertension (PAH).

BACKGROUND: Novel therapeutics for pulmonary arterial hypertension (PAH) with improved safety/tolerability profiles are needed to address continued high rates of morbidity/mortality. METHODS: This Phase 1 study evaluated efficacy/safety of inhaled single-dose MK-5475, an investigational, small-molecule stimulator of soluble guanylate cyclase designed for inhaled delivery via a dry-powder inhaler device, in participants with PAH (Clinicaltrials.gov: NCT03744637). Eligible participants were 18-70 years of age; body mass index ≤35 kg/m2; diagnosis of PAH (Group 1 pulmonary hypertension). In Part 1, participants received double-blind MK-5475 or placebo for safety assessment (primary outcome). In Part 2, 4 panels participated in ≤3 open-label periods. Part 2/Period 1 assessed safety/tolerability. Part 2/Periods 2 and 3, respectively, involved functional respiratory imaging for measuring pulmonary blood volume (secondary outcome) and right heart catheterization for measuring pulmonary vascular resistance (primary outcome). RESULTS: MK-5475 was generally well tolerated without systemic side effects on blood pressure or heart rate up to 24 h post dose. With respect to the primary pharmacodynamic outcome, mean reductions in pulmonary vascular resistance ranged from 21% to 30% across 120 µg and 360 µg doses. CONCLUSIONS: Treatment with inhaled single-dose MK-5475 showed rapid and sustained reductions in pulmonary vascular resistance and increases in pulmonary blood volume. MK-5475 was generally well tolerated versus placebo without vasodilatory systemic side effects. The promising pulmonary selectivity and favorable safety/tolerability profile of MK-5475 seen in this study of adult participants with PAH lays the foundation for further clinical development.

Safety and immunogenicity of intramuscular, single-dose V590 (rVSV-SARS-CoV-2 Vaccine) in healthy adults: Results from a phase 1 randomised, double-blind, placebo-controlled, dose-ranging trial.

BACKGROUND: Vaccines against COVID-19 are needed to overcome challenges associated with mitigating the global pandemic. We report the safety and immunogenicity of V590, a live recombinant vesicular stomatitis virus-based COVID-19 vaccine candidate. METHODS: In this placebo-controlled, double-blind, three-part phase 1 study, healthy adults were randomised to receive a single intramuscular dose of vaccine or placebo. In Part 1, younger (18-54 years) and, in Part 2, older (≥55 years) adults seronegative for SARS-CoV-2 nucleocapsid received one of four V590 dose levels (5.00 × 105; 2.40 × 106; 1.15 × 107; or 5.55 × 107 plaque-forming units [pfu]) or placebo. In Part 3, a single V590 dose level (5.55 × 107 pfu) or placebo was administered to younger SARS-CoV-2 seropositive adults. Primary endpoints included adverse events (AEs) and for Parts 1 and 2 anti-SARS-CoV-2 serum neutralising antibody responses measured by 50% plaque reduction neutralisation (PRNT50) assay at Day 28. Registration NCT04569786 [P001-02]. FINDINGS: 232 participants were randomised and 219 completed the study. In seronegative participants, anti-SARS-CoV-2 spike-specific antibody responses to V590 were low and comparable to placebo across the lower dose levels. At the highest dose level (5.55 × 107 pfu), anti-SARS-CoV-2 spike-specific PRNT50 was 2.3-fold higher than placebo. The most frequently reported AEs were injection-site pain (38.4%), headache (15.1%) and fatigue (13.4%). INTERPRETATION: V590 was generally well-tolerated. However, Day 28 anti-SARS-Cov-2 spike-specific antibody responses in seronegative participants following a single intramuscular administration of V590 were not sufficient to warrant continued development. FUNDING: The study was funded by Merck Sharp & Dohme LLC., a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.

Safety and immunogenicity of the measles vector-based SARS-CoV-2 vaccine candidate, V591, in adults: results from a phase 1/2 randomised, double-blind, placebo-controlled, dose-ranging trial.

BACKGROUND: We report on the safety and immunogenicity of V591, a measles vector-based SARS-CoV-2 vaccine candidate. METHODS: In this multicentre, randomised, placebo-controlled, double-blind, phase 1/2 trial, healthy adults with no history of COVID-19 disease were assigned to intramuscular injection of V591 or placebo (4:1 ratio). In part 1, younger adults (18-55 years) received V591 median tissue culture infectious dose (TCID50)-levels of 1×105 or 1×106 or placebo, 56 days apart. In part 2, younger and older (>55 years) adults received a single dose of one of four (104/105/106/107) or one of two (105/106) V591 TCID50 levels, respectively, or placebo. PRIMARY OUTCOME: safety/tolerability. Secondary outcome: humoral immunogenicity. ClinicalTrials.gov: NCT04498247. FINDINGS: From August-December 2020, 444 participants were screened and 263 randomised (210 V591; 53 placebo); 262 received at least one and 10 received two doses of V591 or placebo. Adverse events were experienced by 140/209 (67.0%) V591 dose-group participants and 37/53 (69.8%) placebo-group participants following injection 1; most frequent were fatigue (57 [27.3%] vs 20 [37.7%]), headache (57 [27.3%] vs 19 [35.8%]), myalgia (35 [16.7%] vs 10 [18.9%]), and injection-site pain (35 [16.7%] vs 4 [7.5%]). No deaths nor vaccine-related serious adverse events occurred. At Day 29, no anti-SARS-CoV-2 spike serum neutralising antibody and IgG-responses were identified in placebo or the three lower V591 dose-groups; responses were detected with V591 1×107 TCID50, although titres were lower than convalescent serum. INTERPRETATION: V591 was generally well tolerated, but immunogenicity was insufficient to warrant continued development. FUNDING: Merck Sharp & Dohme, Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA.

Forward and reverse translational approaches to predict efficacy of neutralizing respiratory syncytial virus (RSV) antibody prophylaxis.

BACKGROUND: Neutralizing mAbs can prevent communicable viral diseases. MK-1654 is a respiratory syncytial virus (RSV) F glycoprotein neutralizing monoclonal antibody (mAb) under development to prevent RSV infection in infants. Development and validation of methods to predict efficacious doses of neutralizing antibodies across patient populations exposed to a time-varying force of infection (i.e., seasonal variation) are necessary. METHODS: Five decades of clinical trial literature were leveraged to build a model-based meta-analysis (MBMA) describing the relationship between RSV serum neutralizing activity (SNA) and clinical endpoints. The MBMA was validated by backward translation to animal challenge experiments and forward translation to predict results of a recent RSV mAb trial. MBMA predictions were evaluated against a human trial of 70 participants who received either placebo or one of four dose-levels of MK-1654 and were challenged with RSV [NCT04086472]. The MBMA was used to perform clinical trial simulations and predict efficacy of MK-1654 in the infant target population. FINDINGS: The MBMA established a quantitative relationship between RSV SNA and clinical endpoints. This relationship was quantitatively consistent with animal model challenge experiments and results of a recently published clinical trial. Additionally, SNA elicited by increasing doses of MK-1654 in humans reduced RSV symptomatic infection rates with a quantitative relationship that approximated the MBMA. The MBMA indicated a high probability that a single dose of ≥ 75 mg of MK-1654 will result in prophylactic efficacy (> 75% for 5 months) in infants. INTERPRETATION: An MBMA approach can predict efficacy of neutralizing antibodies against RSV and potentially other respiratory pathogens.

A Phase 1 Randomized, Double-Blind, Placebo-Controlled Trial to Assess the Safety, Tolerability, and Pharmacokinetics of a Respiratory Syncytial Virus Neutralizing Monoclonal Antibody MK-1654 in Healthy Adults.

Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infection and related morbidity and mortality in infants. Passive immunization with an RSV-neutralizing antibody can provide rapid protection to this vulnerable population. Proof-of-concept for this approach has been demonstrated by palivizumab; however, the use of this antibody is generally restricted to the highest-risk infants due to monthly dosing requirements and its cost. To address the large unmet medical need for most infants, we are evaluating MK-1654, a fully human RSV-neutralizing antibody with half-life extending mutations targeting site IV of the fusion protein. In this 2-part, placebo-controlled, double-blind, first-in-human study, 152 healthy adults were randomized 3:1 to receive a single dose of MK-1654 or placebo in 5 cohorts (100 or 300 mg as an intramuscular dose or 300, 1000, or 3000 mg as an intravenous dose). Safety, pharmacokinetics, antidrug antibodies, and RSV serum-neutralizing antibody titers were evaluated through 1 year. MK-1654 serum concentrations increased proportionally with dose and resulted in corresponding elevations in RSV serum-neutralizing antibody titers. The antibody displayed a half-life of 73 to 88 days and an estimated bioavailability of 69% at the 300-mg dose. The overall safety profile of MK-1654 was similar to placebo, and treatment-emergent antidrug antibodies were low (2.6%) with no associated adverse events. These data support the continued development of MK-1654 for the prevention of RSV disease in infants.

A phase 1, randomized, placebo-controlled study to evaluate the safety and immunogenicity of an mRNA-based RSV prefusion F protein vaccine in healthy younger and older adults.

Respiratory Syncytial Virus (RSV) causes lower respiratory tract infections that can be severe and sometimes fatal. The risk for severe RSV infection is highest in infants and older adults. A safe and effective RSV vaccine for older adults represents a serious unmet medical need due to higher morbidity and mortality in this age group. In this randomized, partially double-blind, placebo-controlled, phase 1 dose-escalation study, we evaluated the safety, tolerability and immunogenicity of an investigational messenger ribonucleic acid (mRNA) vaccine encoding the RSV fusion protein (F) stabilized in the prefusion conformation. The study was conducted in healthy younger adults (ages ≥18 and ≤49 years) and healthy older adults (ages ≥60 and ≤79 years). Participants received mRNA-1777 (V171) or placebo as a single intramuscular dose. For each dose level, three sentinel participants were administered open-label mRNA-1777 (V171). Seventy-two younger adults were randomized and administered 25, 100, or 200 µg mRNA-1777 (V171) or placebo, and 107 older adults were randomized and administered 25, 100, 200 or 300 µg mRNA-1777 (V171) or placebo. Primary objectives were safety and tolerability and secondary objectives included humoral and cell-mediated immunogenicity. All dose levels of mRNA-1777 (V171) were generally well tolerated and no serious adverse events related to the vaccine were reported. Immunization with mRNA-1777 (V171) elicited a humoral immune response as measured by increases in RSV neutralizing antibody titers, serum antibody titers to RSV prefusion F protein, D25 competing antibody titers to RSV prefusion F protein, and cell-mediated immune responses to RSV-F peptides.

Pharmacokinetic-pharmacodynamic (dipeptidyl peptidase-4 inhibition) model to support dose rationale in diabetes patients, including those with renal impairment, for once-weekly administered omarigliptin.

AIMS: To characterize the population pharmacokinetics (PK) and pharmacodynamics (PD) of the once-weekly dipeptidyl peptidase-4 (DPP-4) inhibitor omarigliptin in healthy subjects and patients with type 2 diabetes mellitus, and use these models to support the dosing recommendation for patient labelling including patients with renal impairment. METHODS: PK and PD were assessed from a total of 9827 omarigliptin concentrations collected from 1387 healthy subjects and patients participating in Phase 1, 2 and 3 studies examining single- or multiple-dose weekly administration of omarigliptin at doses ranging from 0.25 to 400 mg. Population PK and PD analyses were performed using nonlinear mixed effect modelling. RESULTS: A semi-mechanistic 2-compartment model with linear unbound clearance and concentration-dependent binding of omarigliptin to the DPP-4 enzyme in both the central and peripheral compartments adequately described omarigliptin PK. Key covariates on omarigliptin PK included reduced unbound clearance with renal impairment. A direct effect sigmoid maximum inhibitory efficacy model adequately described the relationship between omarigliptin plasma concentrations and DPP-4 inhibition. These models supported the current Japan label instructions that the approved omarigliptin 25-mg once-weekly dose be halved in patients with severe renal impairment and in those with end-stage renal disease. Also, if patients missed a dose, the next dose of omarigliptin should be taken as soon as remembered up to and including the day before the next scheduled dose. No other clinically important covariates were identified. CONCLUSION: The models in the present analysis adequately described PK and PD characteristics of omarigliptin and supported the dosing and administration section of the omarigliptin label.

A randomized, double-blind trial evaluating the efficacy and safety of monotherapy with the once-weekly dipeptidyl peptidase-4 inhibitor omarigliptin in people with type 2 diabetes.

AIMS: To assess the efficacy and safety of once-weekly omarigliptin as monotherapy in people with type 2 diabetes mellitus (T2DM). METHODS: People with T2DM not on glucose-lowering medications, or who were washed off monotherapy or low-dose dual therapy, were randomized double-blind to omarigliptin 25 mg (n=165) or matching omarigliptin placebo (n=164) for 24 weeks, followed by a 30-week period to assess continuing efficacy and safety longer-term of omarigliptin during which metformin was added to the placebo group and metformin placebo to the omarigliptin group. RESULTS: From a mean baseline HbA1c of 8.0-8.1%, the least squares mean (95% CI) change from baseline in HbA1c at week 24 (primary endpoint) was -0.49% (-0.73, -0.24) in the omarigliptin group and -0.10% (-0.34, 0.14) in the placebo group, for a between-group difference of -0.39% (-0.59, -0.19) (p<.001). Protocol deviation in use of metformin by 38 of 252 (15%) people whose samples were available for evaluation probably attenuated glycemic efficacy results, as suggested by the LS mean difference -0.53% (-0.75, -0.32) after censoring of such participants. At 24 and 54 weeks, the incidences of adverse events (AEs) were similar in the omarigliptin and placebo groups. During 54 weeks there were no AEs of symptomatic hypoglycemia in the omarigliptin group and 5 AEs in the placebo group. Over 54 weeks, a majority of the omarigliptin treatment had a persistent reduction in HbA1c, remaining rescue-free. CONCLUSIONS: In people with T2DM, omarigliptin monotherapy improved glycemic control over 54 weeks and was generally well tolerated with a low risk of hypoglycemia. ClinicalTrials.gov Identifier: NCT01717313. EudraCT Number: 2012-003626-24.

A randomized, placebo-controlled clinical trial evaluating the safety and efficacy of the once-weekly DPP-4 inhibitor omarigliptin in patients with type 2 diabetes mellitus inadequately controlled by glimepiride and metformin.

BACKGROUND: Type 2 diabetes (T2D) is a progressive disease that often requires a patient to use multiple antihyperglycemic agents to achieve glycemic control with disease progression. Omarigliptin is a once-weekly dipeptidyl peptidase-4 inhibitor. The purpose of this trial was to assess the efficacy and safety of adding omarigliptin to the treatment regimen of patients with T2D inadequately controlled by dual therapy with metformin and glimepiride. METHODS: Patients with T2D and HbA1c ≥7.5% and ≤10.5% while on metformin (≥1500 mg/day) and glimepiride (≥4 mg/day) were randomized to omarigliptin 25 mg once-weekly (N = 154) or placebo (N = 153) for 24 weeks. The primary objective was to assess whether omarigliptin was superior to placebo in reducing HbA1c at Week 24. Secondary objectives were to assess the effects of omarigliptin vs. placebo on FPG and the proportion of subjects attaining HbA1c goals of <7% and <6.5%. RESULTS: From a mean baseline HbA1c of 8.5% (omarigliptin) and 8.6% (placebo), the least squares (LS) mean change from baseline in HbA1c at Week 24 was -0.67% in the omarigliptin group and -0.06% in the placebo group, with a between-group difference (95% CI) of -0.61% (-0.85, -0.38). Treatment with omarigliptin resulted in a significantly greater reduction in FPG relative to placebo (LS mean difference [95% CI] -0.9 mmol/L [-1.4, -0.4]; p < 0.001). The proportion of patients achieving glycemic goals of <7.0% and <6.5% was higher in the omarigliptin group relative to the placebo group. The overall incidences of adverse events (AEs), serious AEs, drug-related AEs and discontinuations were generally similar between treatment groups. The incidence of symptomatic hypoglycemia was 10.5% in the omarigliptin group and 8.5% in the placebo group. Relative to baseline, omarigliptin and placebo treatments were associated with LS mean changes in body weight of -0.1 kg and -0.9 kg, respectively. CONCLUSION: In patients with T2D and inadequate glycemic control on dual therapy with metformin and glimepiride, compared with placebo, once-weekly omarigliptin provided greater improvement in glycemic control and was generally well tolerated. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01704261 , EudraCT Number: 2012-002612-10. Trial Registration Date: October 8, 2012.

A randomized, placebo-controlled study of the cardiovascular safety of the once-weekly DPP-4 inhibitor omarigliptin in patients with type 2 diabetes mellitus.

BACKGROUND: Omarigliptin is a once-weekly (q.w.) oral DPP-4 inhibitor that is approved for the treatment of patients with type 2 diabetes mellitus (T2DM) in Japan. To support approval of omarigliptin in the United States, the clinical development program included a cardiovascular (CV) safety study. Subsequently, a business decision was made not to submit a marketing application for omarigliptin in the United States, and the CV safety study was terminated. Herein we report an analysis of data from that early-terminated study. METHODS: In this randomized, double-blind study, 4202 patients with T2DM and established CV disease were assigned to either omarigliptin 25 mg q.w. or matching placebo in addition to their existing diabetes therapy. A Cox proportional hazards model was used to summarize the primary endpoint of time to first major adverse CV event (MACE, the composite of CV death, nonfatal myocardial infarction, and nonfatal stroke) and the analysis of first event of hospitalization for heart failure (hHF). RESULTS: The median follow-up was approximately 96 weeks (range 1.1-178.6 weeks). The primary MACE outcome occurred in 114/2092 patients in the omarigliptin group (5.45%; 2.96/100 patient-years) and 114/2100 patients in the placebo group (5.43%; 2.97/100 patient-years), with a hazard ratio (HR) of 1.00 (95% confidence interval [CI] 0.77, 1.29). The hHF outcome occurred in 20/2092 patients in the omarigliptin group (0.96%; 0.51/100 patient-years) and 33/2100 patients in the placebo group (1.57%; 0.85/100 patient-years), with an HR of 0.60 (95% CI 0.35, 1.05). After 142 weeks, the least-squares mean difference (omarigliptin vs. placebo) in glycated hemoglobin levels was -0.3% (95% CI -0.46, -0.14). The numbers of patients with adverse events, serious adverse events or discontinued from study medication due to adverse events were similar in the omarigliptin and placebo groups. CONCLUSIONS: In this CV safety study of patients with T2DM and established CV disease, omarigliptin did not increase the risk of MACE or hHF and was generally well tolerated. Trial registration ClinicalTrials.gov: NCT01703208. Registered 05 October 2012.

Use of Prohibited Medication, a Potentially Overlooked Confounder in Clinical Trials: Omarigliptin (Once-weekly DPP-4 Inhibitor) Monotherapy Trial in 18- to 45-year-olds.

PURPOSE: The objective of this clinical trial was to assess the efficacy and safety of omarigliptin monotherapy in young adult patients with type 2 diabetes mellitus (T2DM). Unexpected efficacy results in this trial led to a series of investigations that identified the use of prohibited medication by a substantial number of trial patients. METHODS: Patients with T2DM who were ≥18 to <45 years of age and either drug-naive or not on an antihyperglycemic agent for ≥12 weeks with inadequate glycemic control were randomized in a double-blind manner to receive omarigliptin 25 mg once weekly (n = 102) or placebo once weekly (n = 101) for 24 weeks. The objectives of the trial were to assess the effect of treatment with omarigliptin on glycemic parameters, including levels of glycosylated hemoglobin (HbA1c), 2-hour postmeal glucose, and fasting plasma glucose, and to assess the safety and tolerability of omarigliptin. Additional investigations into trial conduct included the measurement of drug levels for omarigliptin and metformin in blood samples collected for future biomedical research, available for approximately one half of the patients. FINDINGS: The mean age of trial participants was 39.2 years, approximately 60% were male, mean body mass index was 32.5 kg/m2, and mean duration of diabetes was 3.1 years. The mean baseline HbA1c value was 7.9% in the omarigliptin group and 8.1% in the placebo group. After 24 weeks, the least squares mean change (95% CI) in HbA1c value from baseline was -0.33% (-0.60 to -0.06) in the omarigliptin group and -0.45% (-0.72 to -0.18) in the placebo group, with a between-group difference of 0.12% (-0.26 to 0.49; P = 0.535). Similarly, no between-group difference was observed for the other glycemic parameters (2-hour postmeal glucose and fasting plasma glucose levels). No issues were identified in drug allocation, dispensing or supply, patient compliance with trial medication, sample handling or analysis, or site trial conduct that explained the observed results. Measurement of drug levels from future biomedical research samples uncovered the use, with no investigator knowledge, of an antihyperglycemic agent that was prohibited by the protocol (ie, metformin) by 42.4% (39 of 92) of patients. Metformin was used by more patients in the placebo group (57% [25 of 44]) than in the omarigliptin group (29% [14 of 48]). IMPLICATIONS: The use of prohibited metformin in a trial of a dipeptidyl peptidase-4 inhibitor, omarigliptin, introduced a confounding factor that invalidated the results of the trial. This behavior may have been encouraged in the trial by protocol-specified self-monitoring of blood glucose levels. Use of prohibited medication may be an underappreciated confounder in clinical trial research. TRIAL REGISTRATIONS: MK-3102-028 (US); ClinicalTrials.gov identifier, NCT01814748; EudraCT number, 2012-004303-12 (EU).

A Randomized, Placebo-Controlled Trial Evaluating the Safety and Efficacy of Adding Omarigliptin to Antihyperglycemic Therapies in Japanese Patients with Type 2 Diabetes and Inadequate Glycemic Control.

INTRODUCTION: Daily dipeptidyl peptidase-4 (DPP-4) inhibitors are commonly used with other orally administered antihyperglycemic agents (AHA), as combination therapy, to treat Japanese patients with type 2 diabetes. When combination therapy is indicated, use of a once-weekly (q.w.) orally administered DPP-4 inhibitor might be an appropriate therapeutic option for some patients. METHODS: A 52-week trial was conducted to assess the safety and tolerability (primary objectives) and glycemic efficacy (secondary objectives) of the q.w. DPP-4 inhibitor omarigliptin as add-on therapy to five different classes of orally administered AHA [sulfonylurea (SU), glinide (GL), biguanide (BG), thiazolidinedione (TZD), or α-glucosidase inhibitor (AGI)] commonly used in Japan and having different mechanisms of drug action from DPP-4 inhibitors. The trial consisted of an initial 24-week double-blind, placebo-controlled period during which patients (stratified by background AHA) were randomized to omarigliptin 25 mg q.w. or placebo, followed by a 28-week open-label period during which patients on placebo were switched to omarigliptin. RESULTS: After 24 weeks, the percentages of patients with adverse events (AEs), serious AEs, drug-related AEs, AEs of symptomatic hypoglycemia, or who discontinued from trial medication because of an AE were generally similar in the omarigliptin and placebo groups, in all background AHA strata and in the overall population. From a mean baseline HbA1c of approximately 8.0%, the placebo-adjusted least-squares mean changes from baseline ranged from -0.80% (AGI stratum) to -1.16% (TZD stratum); p < 0.001 for all background AHA strata. During the open-label period, no safety signals emerged with longer-term treatment. At week 52, the change from baseline in HbA1c in the omarigliptin/omarigliptin group was similar to that of the placebo/omarigliptin group. CONCLUSIONS: Addition of once-weekly omarigliptin to AHA therapy with an SU, GL, BG, TZD, or AGI for up to 52 weeks was generally safe and well tolerated, and provided persistent efficacy. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov: NCT01697592. FUNDING: MSD K.K., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA.

A randomized clinical trial evaluating the efficacy and safety of the once-weekly dipeptidyl peptidase-4 inhibitor omarigliptin in patients with type 2 diabetes inadequately controlled on metformin monotherapy.

OBJECTIVE: To examine the efficacy and safety of the once-weekly (q.w.) dipeptidyl peptidase-4 inhibitor, omarigliptin, in patients with type 2 diabetes (T2DM) and inadequate glycemic control on metformin monotherapy. METHODS: In a randomized, double-blind trial, patients with T2DM on a stable dose of metformin monotherapy (≥1500 mg/day) with glycated hemoglobin (HbA1c) of 7.0-10.5% were randomized to omarigliptin 25 mg q.w. or matching placebo (n = 201 in both) for 24 weeks (primary timepoint) followed by an additional 80-week treatment period. RESULTS: At week 24, from a mean baseline HbA1c of 8.0-8.1%, the least squares (LS) mean (95% CI) change from baseline in HbA1c (primary end-point) was -0.54% (-0.69%, -0.40%) in the omarigliptin group and 0.00% (-0.14%, 0.15%) in the placebo group, for a between-group difference of -0.55% (-0.75%, -0.34%); p < .001. Between-group differences (LS mean 95% CI) for the secondary end-points of 2-h post-meal glucose and fasting plasma glucose (omarigliptin vs placebo) were -0.8 mmol/L (-1.4, -0.2) (p = .011) and -0.5 mmol/L (-0.9, -0.1) (p = .010), respectively. At week 24, the incidences of symptomatic hypoglycemia and subjects with one or more adverse event (AE), serious AEs, and discontinuations due to an AE were similar in the omarigliptin and placebo groups. Over 104 weeks, omarigliptin treatment provided a clinically meaningful reduction in HbA1c. CONCLUSIONS: In patients with T2DM, adding omarigliptin 25 mg q.w. to metformin monotherapy improved glycemic control over 104 weeks and was generally welltolerated with a low risk of hypoglycemia.

A randomized, double-blind, non-inferiority trial evaluating the efficacy and safety of omarigliptin, a once-weekly DPP-4 inhibitor, or glimepiride in patients with type 2 diabetes inadequately controlled on metformin monotherapy.

OBJECTIVE: To evaluate the efficacy and safety of adding the once-weekly DPP-4 inhibitor omarigliptin or the sulfonylurea glimepiride to the treatment regimen of patients with type 2 diabetes (T2DM) and inadequate glycemic control on metformin monotherapy. METHODS: Patients with T2DM and HbA1c ≥6.5% to ≤9.0% while on a stable dose of metformin (≥1500 mg/day) were randomized to omarigliptin 25 mg once-weekly (n = 376) or glimepiride up to 6 mg once daily (n = 375) for 54 weeks. The primary hypothesis was that omarigliptin is non-inferior to glimepiride in reducing HbA1c at week 54. RESULTS: The mean baseline HbA1c was 7.5% in the omarigliptin group and 7.4% in the glimepiride group. After 54 weeks, the least squares (LS) mean change from baseline in HbA1c was -0.30% in the omarigliptin group and -0.48% in the glimepiride group, with a between-group difference (95% CI) of 0.18% (0.06, 0.30), which met the pre-specified criterion for declaring non-inferiority. The incidence of symptomatic hypoglycemia was 5.3% in the omarigliptin group and 26.7% in the glimepiride group. With the exception of hypoglycemia, the incidences of adverse events and discontinuations were similar between treatment groups. Relative to baseline, omarigliptin was associated with a mean weight loss (-0.4 kg) and glimepiride a mean weight gain (+1.5 kg). CONCLUSIONS: After 54 weeks, as add-on therapy to metformin, once-weekly omarigliptin was generally well tolerated and non-inferior to glimepiride in improving glycemic control, with a lower incidence of hypoglycemia and with weight loss vs weight gain.

A randomised, double-blind, trial of the safety and efficacy of omarigliptin (a once-weekly DPP-4 inhibitor) in subjects with type 2 diabetes and renal impairment.

AIMS: To assess the safety and efficacy of omarigliptin in subjects with type 2 diabetes mellitus (T2DM) and chronic renal impairment (RI). METHODS: Patients with T2DM with moderate RI (estimated glomerular filtration rate [eGFR] ≥30 to <60 mL/min/1.73 m2 ) (N=114), severe RI (eGFR <30 mL/min/1.73 m2 ) (N=55) or end-stage renal disease on dialysis (N=44), who were either not on an antihyperglycaemic agent therapy for at least 12 weeks at screening, washed-off of oral antihyperglycaemic agent monotherapy or low-dose dual combination therapy, or on insulin monotherapy, with baseline glycated haemoglobin (HbA1c) of 6.5%-10.0% were randomised to omarigliptin or to placebo for 24 weeks (primary end-point) followed by a 30-week period with subjects on placebo switched to blinded glipizide (if not on insulin). RESULTS: After 24 weeks, from a mean baseline HbA1c of 8.4% in the omarigliptin group and 8.3% in the placebo group, the least squares mean (95% CI) change from baseline in HbA1c in the overall population (all renal strata combined) was -0.77% (-1.00 to -0.54) in the omarigliptin group and -0.44% (-0.67 to -0.21) in the placebo group; between-group difference of -0.33% (-0.63 to -0.02); P=0.035. After 24 weeks, the incidences of subjects with symptomatic hypoglycaemia, one or more adverse event (AE), drug-related AE, serious AE and discontinuation due to an AE were similar in the omarigliptin and placebo groups. CONCLUSIONS: In this study in subjects with T2DM and RI, relative to placebo, omarigliptin provided clinically meaningful reductions in HbA1c, had a similar incidence of symptomatic hypoglycaemia and was generally well tolerated.

A randomized, placebo- and sitagliptin-controlled trial of the safety and efficacy of omarigliptin, a once-weekly dipeptidyl peptidase-4 inhibitor, in Japanese patients with type 2 diabetes.

AIMS: To assess the safety and efficacy of omarigliptin in Japanese patients with type 2 diabetes (T2D). METHODS: In a 24-week double-blind trial, 414 patients with T2D were randomized to omarigliptin 25 mg once weekly, sitagliptin 50 mg once daily or placebo. The double-blind period was followed by a 28-week open-label extension during which all patients received omarigliptin 25 mg once weekly. Efficacy endpoints were glycated haemoglobin (HbA1c), 2-hour postprandial glucose (PPG) and fasting plasma glucose (FPG) levels. RESULTS: After 24 weeks, the least squares (LS) mean change from baseline in HbA1c was -0.66% for omarigliptin, -0.65% for sitagliptin and 0.13% for placebo. The difference in LS mean for omarigliptin vs placebo was -0.80% ( P < .001). The difference in LS mean for omarigliptin vs sitagliptin was -0.02% (95% confidence interval -0.15, 0.12), which met the criterion for non-inferiority to sitagliptin. Both active treatments provided significant reductions in FPG and 2-hour PPG compared with placebo (P < .001). Over the 24-week double-blind period, there were no clinically meaningful differences in the incidence rates of adverse events among the treatment groups. There was 1 episode of symptomatic hypoglycaemia in the sitagliptin group and none in the omarigliptin or placebo groups. In the 28-week open-label period, omarigliptin provided persistent improvements in glycaemic control without notable change in safety profile compared with the double-blind period. Omarigliptin had no meaningful effect on body weight. CONCLUSIONS: In Japanese patients with T2D, omarigliptin 25 mg once weekly provided significant glucose-lowering compared with placebo and was non-inferior to sitagliptin 50 mg once daily. Omarigliptin was generally well tolerated for up to 52 weeks.

Randomized clinical trial comparing the efficacy and safety of treatment with the once-weekly dipeptidyl peptidase-4 (DPP-4) inhibitor omarigliptin or the once-daily DPP-4 inhibitor sitagliptin in patients with type 2 diabetes inadequately controlled on metformin monotherapy.

AIM: To compare the efficacy and safety of the once-weekly oral dipeptidyl peptidase-4 (DPP-4) inhibitor omarigliptin or once-daily DPP-4 inhibitor sitagliptin in patients with type 2 diabetes (T2DM) and inadequate glycaemic control on metformin. MATERIALS AND METHODS: Patients with T2DM with a glycated haemoglobin (HbA1c) concentration ≥6.5% to ≤9.0% while on a stable dose of metformin (≥1500 mg/d) were randomized in a double-blind manner to receive omarigliptin 25 mg once weekly (n = 322) or sitagliptin 100 mg once daily (n = 320). The primary analysis assessed whether omarigliptin was non-inferior to sitagliptin in reducing HbA1c at week 24, based on the criterion of having an upper bound of the 95% confidence interval (CI) about the difference less than the non-inferiority bound of 0.3%. RESULTS: The mean baseline HbA1c was 7.5% in both groups. After 24 weeks, the least squares (LS) mean change in HbA1c from baseline was -0.47% in the omarigliptin group and -0.43% in the sitagliptin group, with a between-group difference of -0.03% (95% CI -0.15, 0.08). This result met the prespecified criterion for declaring non-inferiority. The LS mean change from baseline in fasting plasma glucose and the percentage of patients with HbA1c <7.0% or <6.5% at week 24 were similar in the two treatment groups. There were no notable differences in adverse events and the incidence of symptomatic hypoglycaemia was low and similar in the groups. CONCLUSIONS: In patients with T2DM and inadequate glycaemic control on metformin, the addition of omarigliptin 25 mg once weekly or sitagliptin 100 mg once daily led to similar improvements in glycaemic control. Both agents were generally well tolerated with a low incidence of hypoglycaemia.

Effects of Extended-Release Niacin and Extended-Release Niacin/Laropiprant on the Pharmacokinetics of Simvastatin in Healthy Subjects.

The use of multiple lipid-modifying agents with different mechanisms of action is often required to regulate lipid levels in patients with dyslipidemia. During combination therapy, alterations in the pharmacokinetics of any of the drugs used and their metabolites may occur. Three separate open-label, randomized, crossover studies evaluated the potential for pharmacokinetic interaction between extended-release niacin (with and without concomitant laropiprant) and simvastatin in healthy subjects. Study 1 used single doses of extended-release niacin and simvastatin; study 2 used multiple-dose coadministration of extended-release niacin/laropiprant and simvastatin in healthy subjects; and study 3 used single doses of both extended-release niacin and the coadministration of extended-release niacin/laropiprant and simvastatin in healthy Chinese subjects. During each treatment period, plasma samples were collected predose and at prespecified postdose time points for pharmacokinetic analyses. The safety and tolerability of simvastatin with and without coadministered extended-release niacin (or extended-release niacin/laropiprant) were assessed by clinical evaluation of adverse experiences. In 2 studies in healthy subjects, modest increases in exposure to simvastatin acid (by ∼60%) by extended-release niacin and extended-release niacin/laropiprant were observed. Based on the clinical experience with simvastatin, these effects are not believed to be clinically meaningful. In the third study on healthy Chinese subjects, no statistically meaningful increases in exposure to simvastatin by extended-release niacin and extended-release niacin/laropiprant were observed. In all populations examined in these studies, the coadministration of extended-release niacin and simvastatin was generally well tolerated.