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BackgroundIn 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.MethodsThe 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.ResultsSummary 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.ConclusionsIn 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.

Neuroinflammation is initiated in response to ischemic stroke, generally with the hallmarks of microglial activation and collateral brain injury contributed by robust inflammatory effects. Triggering receptor expressed on myeloid cells (TREM)-1, an amplifier of the innate immune response, is a critical regulator of inflammation. This study identified that microglial TREM-1 expression was upregulated following cerebral ischemic injury. After pharmacologic inhibition of TREM-1 with synthetic peptide LP17, ischemia-induced infarction and neuronal injury were substantially alleviated. Moreover, blockade of TREM-1 can potentiate cellular proliferation and synaptic plasticity in hippocampus, resulting in long-term functional improvement. Microglial M1 polarization and neutrophil recruitment were remarkably abrogated as mRNA levels of M1 markers, chemokines, and protein levels of myeloperoxidase and intracellular adhesion molecule-1 (ICAM-1) were decreased by LP17. Mechanistically, both in vivo and in vitro, we delineated that TREM-1 can activate downstream pro-inflammatory pathways, CARD9/NF-κB, and NLRP3/caspase-1, through interacting with spleen tyrosine kinase (SYK). In addition, TREM-1-induced SYK initiation was responsible for microglial pyroptosis by elevating levels of gasdermin D (GSDMD), N-terminal fragment of GSDMD (GSDMD-N), and forming GSDMD pores, which can facilitate the release of intracellular inflammatory factors, in microglia. In summary, microglial TREM-1 receptor yielded post-stroke neuroinflammatory damage via associating with SYK.

Aim:To compare the efficacy and safety of monotherapy with sitagliptin and metformin in treatment-naïve patients with type 2 diabetes. Methods: In a double-blind study, 1050 treatment-naïve patients (i.e. not taking an antihyperglycaemic agent for ≥16 weeks prior to study entry) with type 2 diabetes and an HbA 1c 6.5-9% were randomized (1:1) to treatment with once-daily sitagliptin 100 mg (N = 528) or twice-daily metformin 1000 mg (N = 522) for 24 weeks. Metformin was up-titrated from 500 to 2000 mg per day (or maximum tolerated daily dose ≥1000 mg) over a period of 5 weeks. The primary analysis used a per-protocol (PP) approach to assess whether sitagliptin was non-inferior to metformin based on HbA 1c change from baseline at week 24. Non-inferiority was to be declared if the upper boundary of the 95% confidence interval (CI) for the between-group difference in this endpoint was <0.40%. Results:From a mean baseline HbA 1c of 7.2% in the PP population, HbA 1c change from baseline was −0.43% with sitagliptin (n = 455) and −0.57% with metformin (n = 439). The between-group difference (95% CI) was 0.14% (0.06, 0.21), thus confirming non-inferiority. Baseline HbA 1c influenced treatment response, with larger reductions in HbA 1c observed in patients with baseline HbA 1c ≥8% in the sitagliptin (-1.13%; n = 74) and metformin (-1.24%; n = 73) groups. The proportions of patients at week 24 with HbA 1c values at the goals of <7 or <6.5% were 69 and 34% with sitagliptin and 76 and 39% with metformin, respectively. Fasting plasma glucose changes from baseline were −11.5 mg/dL (-0.6 mmol/l) and −19.4 mg/dl (-1.1 mmol/l) with sitagliptin and metformin, respectively (difference in LS mean change from baseline [95% CI] = 8.0 mg/dl [4.5, 11.4]). Both treatments led to similar improvements from baseline in measures of homeostasis model assessment-β cell function (HOMA-β) and insulin resistance (HOMA-IR). The incidence of hypoglycaemia was 1.7% with sitagliptin and 3.3% with metformin (p = 0.116). The incidence of gastrointestinal-related adverse experiences was substantially lower with sitagliptin (11.6%) compared with metformin (20.7%) (difference in incidence [95% CI] = −9.1% [−13.6, −4.7]), primarily because of significantly decreased incidences of diarrhoea (3.6 vs. 10.9%; p < 0.001) and nausea (1.1 vs. 3.1%; p = 0.032). Body weight was reduced from baseline with both sitagliptin (LS mean change [95% CI] = −0.6 kg [−0.9, −0.4]) and metformin (-1.9 kg [-2.2, −1.7]) (p < 0.001 for sitagliptin vs. metformin). Conclusions:In this 24-week monotherapy study, sitagliptin was non-inferior to metformin in improving HbA 1c in treatment-naïve patients with type 2 diabetes. Although both treatments were generally well tolerated, a lower incidence of gastrointestinal-related adverse experiences was observed with sitagliptin.