Search

BACKGROUND: The quadrivalent (types 6, 11, 16, and 18) human papillomavirus (HPV) L1 virus-like-particle vaccine was 95%-100% effective in preventing cervical and genital disease related to HPV-6, -11, -16, and -18. Vaccine efficacy is thought to be mediated by humoral immunity. Here, we analyze the effect of the baseline characteristics of subjects on vaccine-induced immune responses. METHODS: Immunogenicity data from 12,343 subjects 9-26 years old randomized to quadrivalent HPV vaccine or placebo in phase 2/3 studies were analyzed. Covariates examined were day 1 HPV serostatus, age, race/ethnicity, region of residence, lactation status, hormonal contraceptive usage, smoking status, Pap test diagnosis, immunosuppressant or anti-inflammatory agent use, and number of sex partners. Anti-HPV responses were summarized as serum anti-HPV-6, -11, -16, or -18 geometric mean titers 1 month after dose 3. RESULTS: Age at vaccination initiation was inversely proportional to the vaccine-induced anti-HPV response. Vaccination of subpopulations of subjects who were seropositive at day 1 to a vaccine HPV type resulted in more robust anti-HPV responses to that type, compared with those in subjects who were seronegative at baseline. Anti-HPV responses were comparable among the remaining demographic subgroups. CONCLUSIONS: The immunogenicity of quadrivalent HPV vaccine was comparable among subjects with differing baseline characteristics. These data support vaccination with quadrivalent HPV vaccine across a broad range of baseline subject characteristics. Copyright © 2007 Infectious Diseases Society of America [ABSTRACT FROM AUTHOR]

Abstract Objective To compare the incidence of cardiovascular events and mortality in patients with type 2 diabetes mellitus treated with sitagliptin or non-sitagliptin comparators. Methods A post hoc assessment of cardiovascular safety in 14,611 patients was performed by pooling data from 25 double-blind studies, which randomised patients at baseline to sitagliptin 100 mg/day or a non-sitagliptin comparator (i.e., non-exposed). Included studies were limited to those at least 12 weeks in duration (range: 12 to 104 weeks). Patient-level data were used in this analysis of major adverse cardiovascular events (MACE) including ischaemic events and cardiovascular deaths. Analyses were performed in three cohorts: the entire 25-study cohort, the cohort from placebo-controlled portions of studies (n=19), and the cohort from studies comparing sitagliptin to a sulphonylurea (n=3). Results In the entire cohort analysis, 78 patients had at least 1 reported MACE-related event, with 40 in the sitagliptin group and 38 in the non-exposed group. The exposure-adjusted incidence rate was 0.65 per 100 patient-years in the sitagliptin group and 0.74 in the non-exposed group (incidence rate ratio = 0.83 [95% confidence interval (CI): 0.53, 1.30]). In the analysis comparing sitagliptin to placebo, the exposure-adjusted incidence rate was 0.80 per 100-patient-years with sitagliptin and 0.76 with placebo (incidence rate ratio = 1.01 [95% CI: 0.55, 1.86]). In the analysis comparing sitagliptin to sulphonylurea, the exposure-adjusted incidence rate was 0.00 per 100 patient-years with sitagliptin and 0.86 with sulphonylurea (incidence rate ratio = 0.00 [95% CI: 0.00, 0.31]). Conclusion A pooled analysis of 25 randomised clinical trials does not indicate that treatment with sitagliptin increases cardiovascular risk in patients with type 2 diabetes mellitus. In a subanalysis, a higher rate of cardiovascular-related events was associated with sulphonylurea relative to sitagliptin.

Abstract Background In a previous pooled analysis of 12 double-blind clinical studies that included data on 6,139 patients with type 2 diabetes, treatment with sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, was shown to be generally well tolerated compared with treatment with control agents. As clinical development of sitagliptin continues, additional studies have been completed, and more patients have been exposed to sitagliptin. The purpose of the present analysis is to update the safety and tolerability assessment of sitagliptin by pooling data from 19 double-blind clinical studies. Methods The present analysis included data from 10,246 patients with type 2 diabetes who received either sitagliptin 100 mg/day (N = 5,429; sitagliptin group) or a comparator agent (placebo or an active comparator) (N = 4,817; non-exposed group). The 19 studies from which this pooled population was drawn represent the double-blind, randomized studies that included patients treated with the usual clinical dose of sitagliptin (100 mg/day) for between 12 weeks and 2 years and for which results were available as of July 2009. These 19 studies assessed sitagliptin taken as monotherapy, initial combination therapy with metformin or pioglitazone, or as add-on combination therapy with other antihyperglycemic agents (metformin, pioglitazone, a sulfonylurea ± metformin, insulin ± metformin, or rosiglitazone + metformin). Patients in the non-exposed group were taking placebo, metformin, pioglitazone, a sulfonylurea ± metformin, insulin ± metformin, or rosiglitazone + metformin. The analysis used patient-level data from each study to evaluate between-group differences in the exposure-adjusted incidence rates of adverse events. Results Summary measures of overall adverse events were similar in the sitagliptin and non-exposed groups, except for an increased incidence of drug-related adverse events in the non-exposed group. Incidence rates of specific adverse events were also generally similar between the two groups, except for increased incidence rates of hypoglycemia, related to the greater use of a sulfonylurea, and diarrhea, related to the greater use of metformin, in the non-exposed group and constipation in the sitagliptin group. Treatment with sitagliptin was not associated with an increased risk of major adverse cardiovascular events. Conclusions In this updated pooled safety analysis of data from 10,246 patients with type 2 diabetes, sitagliptin 100 mg/day was generally well tolerated in clinical trials of up to 2 years in duration.

Composite time-to-event endpoints are commonly used in cardiovascular outcome trials. For example, the IMPROVE-IT trial comparing ezetimibe+simvastatin to placebo+simvastatin in 18,144 patients with acute coronary syndrome used a primary composite endpoint with five component outcomes: (1) cardiovascular death, (2) non-fatal stroke, (3) non-fatal myocardial infarction, (4) coronary revascularization ≥30 days after randomization, and (5) unstable angina requiring hospitalization. In such settings, the traditional analysis compares treatments using the observed time to the occurrence of the first (i.e. earliest) component outcome for each patient. This approach ignores information for subsequent outcome(s), possibly leading to reduced power to demonstrate the benefit of the test versus the control treatment. We use real data examples and simulations to contrast the traditional approach with several alternative approaches that use data for all the intra-patient component outcomes, not just the first., Competing Interests: Declaration of conflicting interestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: All authors are paid employees of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.

Missing data are commonly encountered in clinical trials due to dropout or nonadherence to study procedures. In trials in which recurrent events are of interest, the observed count can be an undercount of the events if a patient drops out before the end of the study. In many applications, the data are not necessarily missing at random and it is often not possible to test the missing at random assumption. Consequently, it is critical to conduct sensitivity analysis. We develop a control-based multiple imputation method for recurrent events data, where patients who drop out of the study are assumed to have a similar response profile to those in the control group after dropping out. Specifically, we consider the copy reference approach and the jump to reference approach. We model the recurrent event data using a semiparametric proportional intensity frailty model with the baseline hazard function completely unspecified. We develop nonparametric maximum likelihood estimation and inference procedures. We then impute the missing data based on the large sample distribution of the resulting estimators. The variance estimation is corrected by a bootstrap procedure. Simulation studies demonstrate the proposed method performs well in practical settings. We provide applications to two clinical trials.

Objective: To assess the safety and efficacy of ertugliflozin over 104 weeks in patients with type 2 diabetes mellitus (T2DM) inadequately controlled on metformin. Methods: In this double-blind, multicenter, randomized, phase III study (VERTIS SU; NCT01999218), adults with T2DM and glycated hemoglobin (HbA1c) 7.0-9.0% on metformin ≥1500 mg/day received ertugliflozin 5 mg or 15 mg, or glimepiride. The primary efficacy time point was Week 52; double-blinded treatment continued until Week 104. Results: Baseline characteristics of randomized, treated patients ( n  = 1315) were similar across groups (mean age 58.2 years, HbA1c 7.8%); 76.4% completed the study; 61.6% completed on study medication. Mean glimepiride dose at 104 weeks was 3.5 mg/day. At Week 104, least squares mean change from baseline in HbA1c (95% confidence intervals) were -0.3% (-0.4, -0.2), -0.4% (-0.5, -0.3) and -0.4% (-0.5, -0.3) for ertugliflozin 5 mg, 15 mg, and glimepiride, respectively. Ertugliflozin provided sustained reductions in body weight and systolic blood pressure (SBP) over 104 weeks. The incidence of adverse events (AEs) and serious AEs was similar across groups. The incidence of symptomatic hypoglycemia was 3.8%, 6.4% and 22.1% in the ertugliflozin 5 mg, 15 mg, and glimepiride groups, respectively. Genital mycotic infections were reported in 5.3%, 2.6% and 0% of men, respectively, and 9.2%, 12.3% and 1.4% of women, respectively. The incidence of urinary tract infection and hypovolemia AEs was similar across groups. Conclusions: Ertugliflozin was well tolerated and provided clinically meaningful glycemic control and durable reductions in body weight and SBP over 104 weeks.

With the growth in co-development deals between pharmaceutical companies and the increased use of contract research organizations (CROs) in drug development, more and more employees are encountering projects that require working across different companies. Navigating the mix of corporate cultures as well as variations in standards and procedures can lead to unanticipated challenges and delays. The development of ertugliflozin, a recently approved medicine for type 2 diabetes mellitus, involved both co-development and CRO engagement across 4 companies. Challenges to combining processes and systems across the 4 companies were encountered and resolved. Early decisions for adoption of standards and processes as well as the organization of committees and communication pathways were key to the success of this ambitious program. Here we share our experiences and lessons learned with respect to the analysis and reporting of clinical trial results.

Background: Ertugliflozin is an inhibitor of sodium-glucose co-transporter-2 (SGLT2), approved in the United States and European Union to improve glycemic control in adults with type 2 diabetes mellitus (T2DM). The VERTIS cardiovascular (CV) outcomes trial (NCT01986881) has a primary objective to demonstrate non-inferiority of ertugliflozin versus placebo on major adverse CV events: time to the first event of CV death, nonfatal myocardial infarction, or nonfatal stroke. Secondary objectives are to demonstrate superiority of ertugliflozin versus placebo on time to: 1) the composite outcome of CV death or hospitalization for heart failure (HF); 2) CV death; and 3) the composite outcome of renal death, dialysis/transplant, or doubling of serum creatinine from baseline., Methods: Patients ≥40 years old with T2DM (HbA1c 7.0-10.5%) and established atherosclerotic cardiovascular disease (ASCVD) of the coronary, cerebral, and/or peripheral arterial systems, were randomized 1:1:1 to once daily double-blind placebo, ertugliflozin 5 mg or 15 mg added to existing therapy., Results: 8246 patients were randomized and 8238 received at least 1 dose of investigational product. Mean age was 64.4 years, 11.0% were ≥75 years old, and mean diabetes duration was 12.9 years with screening HbA1c of 8.3%. At entry, coronary artery disease, cerebrovascular disease, and peripheral arterial disease were present in 76.3%, 23.1%, and 18.8% of patients, respectively. HF was present in 23.1%, and Stage 3 kidney disease in 21.6% of patients., Conclusion: The results from the VERTIS-CV trial will define the CV and renal safety and efficacy of ertugliflozin in patients with T2DM and ASCVD., (Copyright © 2018. Published by Elsevier Inc.)

Aim: To evaluate the efficacy and safety of ertugliflozin and sitagliptin co-administration vs the individual agents in patients with type 2 diabetes who are inadequately controlled with metformin., Methods: In this study (Clinicaltrials.gov NCT02099110), patients with glycated haemoglobin (HbA1c) ≥7.5% and ≤11.0% (≥58 and ≤97 mmol/mol) with metformin ≥1500 mg/d (n = 1233) were randomized to ertugliflozin 5 (E5) or 15 (E15) mg/d, sitagliptin 100 mg/d (S100) or to co-administration of E5/S100 or E15/S100. The primary endpoint was change from baseline in HbA1c at Week 26., Results: At Week 26, least squares mean HbA1c reductions from baseline were greater with E5/S100 (-1.5%) and E15/S100 (-1.5%) than with individual agents (-1.0%, -1.1% and -1.1% for E5, E15 and S100, respectively; P < .001 for all comparisons). HbA1c <7.0% (<53 mmol/mol) was achieved by 26.4%, 31.9%, 32.8%, 52.3% and 49.2% of patients in the E5, E15, S100, E5/S100 and E15/S100 groups, respectively. Fasting plasma glucose reductions were significantly greater with E5/S100 and E15/S100 compared with individual agents. Body weight and systolic blood pressure (SBP) significantly decreased with E5/S100 and E15/S100 vs S100 alone. Glycaemic control, body weight and SBP effects of ertugliflozin were maintained to Week 52. Genital mycotic infections were more common among ertugliflozin-treated patients compared with those treated with S100. Incidences of symptomatic hypoglycaemia and adverse events related to hypovolaemia or urinary tract infection were similar among groups., Conclusions: In patients with uncontrolled type 2 diabetes while using metformin, co-administration of ertugliflozin and sitagliptin provided more effective glycaemic control through 52 weeks compared with the individual agents., (© 2017 The Authors. Diabetes, Obesity and Metabolism published by John Wiley & Sons Ltd.)

Aims: To assess ertugliflozin in patients with type 2 diabetes who are inadequately controlled by metformin and sitagliptin., Materials and Methods: In this double-blind randomized study (Clinicaltrials.gov NCT02036515), patients (glycated haemoglobin [HbA1c] 7.0% to 10.5% [53-91 mmol/mol] receiving metformin ≥1500 mg/d and sitagliptin 100 mg/d; estimated glomerular filtration rate [eGFR] ≥60 mL/min/1.73 m 2 ) were randomized to ertugliflozin 5 mg once-daily, 15 mg once-daily or placebo. The primary efficacy endpoint was change from baseline in HbA1c at Week 26; treatment was continued until Week 52., Results: A total of 464 patients were randomized (mean baseline HbA1c, 8.0% [64.3 mmol/mol]; eGFR, 87.9 mL/min/1.73 m 2 ). After 26 weeks, placebo-adjusted least squares (LS) mean changes in HbA1c from baseline were -0.7% (-7.5 mmol/mol) and -0.8% (-8.3 mmol/mol) for ertugliflozin 5 and 15 mg, respectively (both P < .001); 17.0%, 32.1% and 39.9% of patients receiving placebo, ertugliflozin 5 mg or ertugliflozin 15 mg, respectively, had HbA1c <7.0% (53 mmol/mol). Significant reductions in fasting plasma glucose, body weight (BW) and systolic blood pressure (SBP) were observed with ertugliflozin relative to placebo. The positive effects of ertugliflozin on glycaemic control, BW and SBP were maintained through Week 52. A higher incidence of genital mycotic infections was observed in male and female patients receiving ertugliflozin (3.7%-14.1%) vs placebo (0%-1.9%) through Week 52. The incidence of urinary tract infections, symptomatic hypoglycaemia and hypovolaemia adverse events were not meaningfully different across groups., Conclusions: Ertugliflozin added to metformin and sitagliptin was well-tolerated, and provided clinically meaningful, durable glycaemic control, BW and SBP reductions vs placebo over 52 weeks., (© 2017 The Authors. Diabetes, Obesity and Metabolism published by John Wiley & Sons Ltd.)

Introduction: Ertugliflozin is a sodium-glucose cotransporter 2 inhibitor in development for type 2 diabetes mellitus (T2DM). The safety and efficacy of ertugliflozin were evaluated over 52 weeks in patients with chronic kidney disease (CKD)., Methods: In this double-blind randomized study (NCT01986855), patients with glycated hemoglobin (A1C) 7.0-10.5% and stage 3 CKD [estimated glomerular filtration rate (eGFR) ≥ 30 to < 60 mL/min/1.73 m 2 ] who were undergoing treatment with standard diabetes therapy (or therapies) including insulin and/or sulfonylureas were randomized to once-daily ertugliflozin 5 mg, 15 mg, or placebo. Patients on metformin underwent a pre-randomization ≥ 10-week wash-off period. The primary endpoint was change from baseline in A1C at week 26 in the overall cohort. Secondary efficacy endpoints were assessed in the stage 3A CKD cohort (eGFR ≥ 45 to < 60 mL/min/1.73 m 2 ) at weeks 26 and 52. Safety was assessed in the overall cohort., Results: 468 patients were randomized (baseline mean A1C 8.2%). At week 26, reductions from baseline in A1C were observed across groups in the overall cohort [least squares mean changes (95% confidence interval) - 0.3% (- 0.4, - 0.1), - 0.3% (- 0.4, - 0.1), and - 0.4% (- 0.6, - 0.3) for placebo and for ertugliflozin 5 mg and 15 mg, respectively]. Prohibited use of metformin was identified in ~ 17% of patients and impacted evaluation of the primary endpoint. Greater reductions from baseline in body weight, fasting plasma glucose, and systolic blood pressure were observed with ertugliflozin versus placebo at week 26 (stage 3A CKD cohort). The incidences of urinary tract infections, genital mycotic infections, and hypoglycemia adverse events were not meaningfully different between groups. The incidence of hypovolemia-related adverse events was higher with ertugliflozin relative to placebo., Conclusion: Although surreptitious metformin use impacted the primary analysis, reductions in blood glucose and body weight were observed with ertugliflozin in patients with T2DM and stage 3 CKD; ertugliflozin had an acceptable safety profile., Funding: Merck Sharp & Dohme Corp. a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA and Pfizer Inc., Trial Registration: Clinicaltrials.gov identifier NCT01986855.

Introduction: Ertugliflozin is an oral sodium-glucose cotransporter 2 inhibitor that is being developed to treat type 2 diabetes mellitus (T2DM). This study assessed the efficacy and safety of co-initiation of ertugliflozin and sitagliptin compared with placebo in patients with T2DM inadequately controlled on diet and exercise., Methods: In this phase III, randomized, double-blind, multicenter, placebo-controlled 26-week study (NCT02226003), patients with T2DM and glycated hemoglobin (HbA1c) 8.0-10.5% on diet/exercise were randomized 1:1:1 to ertugliflozin 5 mg once daily (QD) and sitagliptin 100 mg QD (E5/S100), ertugliflozin 15 mg QD and sitagliptin 100 mg QD (E15/S100), or placebo. The primary efficacy endpoint was the change from baseline in HbA1c at week 26., Results: The mean baseline HbA1c of the randomized patients (n = 291) was 8.9%. At week 26, both ertugliflozin/sitagliptin treatments provided significant reductions from baseline in HbA1c compared with placebo [least squares mean HbA1c change (95% confidence intervals) from baseline was - 0.4% (- 0.7, - 0.2), - 1.6% (- 1.8, - 1.4), and - 1.7% (- 1.9, - 1.5) for placebo, E5/S100, and E15/S100, respectively]. At week 26, 8.3%, 35.7%, and 31.3% of patients receiving placebo, E5/S100, and E15/S100, respectively, had HbA1c < 7.0%. Significant reductions in fasting plasma glucose, 2-h post-prandial glucose, body weight, and systolic blood pressure were observed with both ertugliflozin/sitagliptin groups compared with placebo. The incidence of adverse events (AEs) was similar across the groups. The incidences of the pre-specified AEs of urinary tract infection, genital mycotic infection, symptomatic hypoglycemia, and hypovolemia were low and not meaningfully different across groups., Conclusion: Co-initiation of ertugliflozin with sitagliptin in patients with T2DM inadequately controlled on diet and exercise provided a clinically meaningful improvement in glycemic control over 26 weeks., Clinical Trial Registration: Clinicaltrials.gov NCT02226003.

Introduction: This study assessed the safety and efficacy of ertugliflozin (an oral sodium-glucose cotransporter 2 inhibitor) vs. glimepiride in patients with type 2 diabetes mellitus (T2DM) inadequately controlled on metformin., Methods: This phase III, double-blind, non-inferiority study (NCT01999218) randomized patients with HbA1c ≥ 7.0% and ≤ 9.0% on stable metformin ≥ 1500 mg/day 1:1:1 to ertugliflozin 15 or 5 mg once-daily (QD), or glimepiride (titrated from 1 mg QD). The primary hypothesis was that ertugliflozin 15 mg was non-inferior to glimepiride on HbA1c (non-inferiority criterion: upper bound of the 95% confidence interval [CI] about the treatment difference < 0.3%)., Results: Mean baseline HbA1c of randomized patients (N = 1326) was 7.8%. Mean and median doses of glimepiride were 3.0 mg/day throughout the study. At week 52, the least squares mean change (95% CI) from baseline in HbA1c was - 0.6% (- 0.7, - 0.5), - 0.6% (- 0.6, - 0.5), and - 0.7% (- 0.8, - 0.7) in the ertugliflozin 15 mg, ertugliflozin 5 mg, and glimepiride groups, respectively. The between-group difference for ertugliflozin 15 mg and glimepiride of 0.1% (- 0.0, 0.2) met the pre-specified non-inferiority criterion. Relative to glimepiride, greater body weight and systolic blood pressure (SBP) reductions were observed with ertugliflozin. The overall incidence of adverse events (AEs) was similar across groups. The incidence of symptomatic hypoglycemia and genital mycotic infection (GMI) were, respectively, lower and higher with ertugliflozin relative to glimepiride. The incidences of urinary tract infection and hypovolemia AEs were not meaningfully different among the groups., Conclusions: Ertugliflozin 15 mg was non-inferior to glimepiride in reducing HbA1c when added to metformin in patients with T2DM. Ertugliflozin had an acceptable safety profile and resulted in less hypoglycemia and more GMIs than glimepiride., Clinical Trial Registration: Clinicaltrials.gov NCT01999218.

In clinical trials, missing data commonly arise through nonadherence to the randomized treatment or to study procedure. For trials in which recurrent event endpoints are of interests, conventional analyses using the proportional intensity model or the count model assume that the data are missing at random, which cannot be tested using the observed data alone. Thus, sensitivity analyses are recommended. We implement the control-based multiple imputation as sensitivity analyses for the recurrent event data. We model the recurrent event using a piecewise exponential proportional intensity model with frailty and sample the parameters from the posterior distribution. We impute the number of events after dropped out and correct the variance estimation using a bootstrap procedure. We apply the method to an application of sitagliptin study., (Copyright © 2017 John Wiley & Sons, Ltd.)

Aims: To conduct a phase III study to evaluate the efficacy and safety of ertugliflozin monotherapy in people with type 2 diabetes., Materials and Methods: This was a 52-week, double-blind, multicentre, randomized, parallel-group study with a 26-week, placebo-controlled treatment period (phase A), followed by a 26-week active-controlled treatment period (phase B) in 461 men and women, aged ≥18 years with inadequate glycaemic control (glycated haemoglobin [HbA1c] concentration 7.0% to 10.5% [53-91 mmol/mol], inclusive) despite diet and exercise. Results from phase A are reported in the present paper. The primary endpoint was the change in HbA1c from baseline to week 26., Results: At week 26, the placebo-adjusted least squares mean HbA1c changes from baseline were -0.99% and -1.16% for the ertugliflozin 5 and 15 mg doses, respectively ( P  < .001 for both doses). The odds of having HbA1c <7.0% (53 mmol/mol) were significantly greater in the ertugliflozin 5 and 15 mg groups compared with the placebo group. Both doses of ertugliflozin significantly lowered fasting plasma glucose and 2-hour postprandial glucose levels and body weight. The placebo-adjusted differences in changes from baseline in systolic blood pressure were not statistically significant. A higher incidence of genital mycotic infections occurred in men and women treated with ertugliflozin compared with placebo. There was no significant difference between treatments in the proportion of participants with symptomatic hypoglycaemia or adverse events associated with urinary tract infection or hypovolaemia., Conclusions: Ertugliflozin 5 and 15 mg treatment for 26 weeks provides effective glycaemic control, reduces body weight and is generally well tolerated, when used as monotherapy., (© 2017 John Wiley & Sons Ltd.)

Objective: To evaluate the efficacy of once daily sitagliptin 100 mg as monotherapy or as add-on to metformin in patients with type 2 diabetes mellitus (T2DM) over 2 years of treatment., Research Design and Methods: The monotherapy analysis used pooled 104 week data from 64 patients in two randomized, double-blind trials evaluating the safety and efficacy of sitagliptin monotherapy. Data used were from patients who were randomized to sitagliptin 100 mg/day, were not on an antihyperglycemic agent at the screening visit, had baseline A1C of 7.0%-10.0%, and had Week 104 A1C measurements. The add-on to metformin analysis used pooled data from 347 patients in two randomized double-blind trials evaluating the safety and efficacy of sitagliptin + metformin combination therapy. Data used were from patients who were randomized to sitagliptin 100 mg/day + metformin ≥1500 mg/day, had baseline A1C of 7%-10%, and had Week 104 A1C measurements. Excluded from either analysis were patients who discontinued prior to 2 years (e.g., due to lack of efficacy, a need for rescue medications, or adverse experiences). Analysis endpoints were A1C, fasting plasma glucose (FPG), HOMA-β, proinsulin/insulin (P/I) ratio, and for monotherapy, 2 hour post-meal plasma glucose (PMG)., Results: For the pooled monotherapy cohort, after 2 years of treatment, mean A1C, FPG, and 2 hour PMG decreased from baseline values of 7.9%, 156 mg/dL, and 223 mg/dL to 6.9%, 143 mg/dL, and 191 mg/dL, respectively, while HOMA-β increased from 67% to 85% and P/I ratio improved from 0.57 to 0.28. For the pooled add-on to metformin cohort, after 2 years of treatment, mean A1C and FPG decreased from baseline values of 7.7% and 160 mg/dL to 6.9% and 140 mg/dL, respectively, while HOMA-β increased from 50% to 62% and P/I ratio improved from 0.33 to 0.28. These analyses are limited in that only patients who were able to complete 104 weeks of study were included., Conclusion: In the subset of patients with T2DM who maintained and completed treatment for 2 years with sitagliptin as monotherapy or as add-on to metformin, improvements in glycemic control and measures of β-cell function were observed over the course of treatment.

Background: Administration of two doses of hepatitis A (HA) vaccine to children > or = 2 years of age has been shown to be protective. The present study assessed whether HA vaccine can be administered as early as 6 months of age and whether it can be administered concomitantly with a hexavalent (HV) vaccine at this age., Methods: In an open label, randomized, parallel group study, the liquid HV vaccine (HEXAVAC) (diphtheria, tetanus, 2-component acellular pertussis, inactivated poliomyelitis vaccine, Haemophilus influenzae type b conjugated to tetanus protein and hepatitis B) was administered at 2, 4, 6, and 12 months of age to all children. HA vaccine (VAQTA) was given at 7 and 13 months in the separate administration group (Group 1) and at 6 and 12 months in the concomitant administration group (Group 2). Serum samples were obtained at 2, 7, 12, and 14 months in Group 1 and at 2, 7, 12, and 13 months in Group 2. The primary immunogenicity outcomes were the seroconversion rates for HA 1 month after the second dose of HA vaccine in initially seronegative subjects, and the seroconversion rates for each HV antigen 1 month after the third dose of the HV vaccine (both at 7 months of age)., Results: HA seropositivity rates 1 month after the second dose were 100% in both groups, regardless of initial serostatus. The responses to each HV antigen 1 month after the third dose were similar in both groups. The vaccines were generally well tolerated in both groups regardless of vaccine(s) administered., Conclusions: A schedule of two doses of HA vaccine, 6 months apart beginning at 6 months of age is highly immunogenic and well tolerated when administered alone or concomitantly with HV vaccine at 6 and 12 months of age.

The duration over which antibody responses persist following HPV vaccination is unknown. To estimate the longevity of responses induced by HPV-16 vaccination, two models were fitted to serum anti-HPV-16 levels measured during a 48-month study period. The first was a conventional model of antibody decay and the second was a modified model that accounts for long-lived immune memory. Using the antibody decay model, it was estimated that following administration of a three-dose regimen of HPV-16 vaccine in women aged 16-23 years, anti-HPV-16 levels will remain above those induced naturally by HPV-16 infection for 12 years, and above detectable levels for 32 years in 50% of vaccinees. With the modified model, which fitted the data better (p<0.001), it was estimated that near life-long persistence of anti-HPV-16 following vaccination is expected at titer levels above those associated with reduction of natural HPV-16 infection in 76% of these subjects, and above detectable levels in 99% of these subjects.

Exposure to infection information is important for estimating vaccine efficacy, but it is difficult to collect and prone to missingness and mismeasurement. We discuss study designs that collect detailed exposure information from only a small subset of participants while collecting crude exposure information from all participants and treat estimation of vaccine efficacy in the missing data/measurement error framework. We extend the discordant partner design for HIV vaccine trials of Golm, Halloran, and Longini (1998, Statistics in Medicine, 17, 2335-2352.) to the more complex augmented trial design of Longini, Datta, and Halloran (1996, Journal of Acquired Immune Deficiency Syndromes and Human Retrovirology 13, 440-447) and Datta, Halloran, and Longini (1998, Statistics in Medicine 17, 185-200). The model for this design includes three exposure covariates and both univariate and bivariate outcomes. We adapt recently developed semiparametric missing data methods of Reilly and Pepe (1995, Biometrika 82, 299 314), Carroll and Wand (1991, Journal of the Royal Statistical Society, Series B 53, 573-585), and Pepe and Fleming (1991, Journal of the American Statistical Association 86, 108-113) to the augmented vaccine trial design. We demonstrate with simulated HIV vaccine trial data the improvements in bias and efficiency when combining the different levels of exposure information to estimate vaccine efficacy for reducing both susceptibility and infectiousness. We show that the semiparametric methods estimate both efficacy parameters without bias when the good exposure information is either missing completely at random or missing at random. The pseudolikelihood method of Carroll and Wand (1991) and Pepe and Fleming (1991) was the more efficient of the two semiparametric methods.

Exposure to infection information is important for estimating vaccine efficacy, but it is difficult to collect and inherently prone to missingness and mismeasurement. It is, therefore, generally not feasible to collect good exposure information on all participants in a large vaccine trial. We discuss study designs that collect detailed exposure information for only a small subset of trial participants, while collecting crude exposure information on all participants, and treat estimation of vaccine efficacy in the missing data/measurement error framework. We demonstrate with the example of an HIV vaccine trial the improvements in bias and efficiency when we combine the different levels of exposure information to estimate vaccine efficacy for reducing both susceptibility and infectiousness. We compare the performance of recently developed semi-parametric missing data methods of Pepe and Fleming and Carroll and Wand, Robins, Hsieh and Newey, and Reilly and Pepe.