Clinical Impact of ITCA 650, a Novel Drug-Device GLP-1 Receptor Agonist, in Uncontrolled Type 2 Diabetes and Very High Baseline HbA1c: The FREEDOM-1 HBL (High Baseline) Study.

OBJECTIVE: ITCA 650 is a subdermal osmotic mini-pump that continuously delivers exenatide subcutaneously for 3-6 months. The efficacy, safety, and tolerability of ITCA 650 added to diet and exercise alone or combined with metformin, sulfonylurea, or thiazolidinedione monotherapy or a combination of these drugs was evaluated in poorly controlled patients with type 2 diabetes (T2D) who were ineligible for participation in a placebo-controlled study (FREEDOM-1) because of severe hyperglycemia (HbA1c >10% [86 mmol/mol]). RESEARCH DESIGN AND METHODS: This 39-week, open-label, phase 3 trial enrolled patients aged 18-80 years with HbA1c >10% to ≤12% (86-108 mmol/mol) and BMI 25-45 kg/m2. Patients received ITCA 650 20 µg/day for 13 weeks, then 60 µg/day for 26 weeks. The primary end point was change in HbA1c at week 39. RESULTS: Sixty patients were enrolled. At baseline, mean HbA1c was 10.8% (94.7 mmol/mol) and mean (± SD) duration of diabetes was 8.6 (± 5.3) years. At week 39, there was a mean reduction in HbA1c of -2.8% (-30.3 mmol/mol; P < 0.001 vs. baseline) and in body weight of -1.2 kg (P = 0.105), and 25% of patients achieved HbA1c <7% (53 mmol/mol). A reduction in HbA1c of ≥1% (≥10.9 mmol/mol) occurred in 90% of patients. The most common adverse events were nausea, vomiting, diarrhea, and headache. Gastrointestinal adverse events were generally transient and subsided over time; only 4 patients (6.7%) discontinued for gastrointestinal events. CONCLUSIONS: Treatment with ITCA 650, the first injection-free glucagon-like peptide 1 receptor agonist, resulted in significant improvements in glycemic control in poorly controlled long-standing T2D patients with a high baseline HbA1c >10%.

Efficacy and Safety of ITCA 650, a Novel Drug-Device GLP-1 Receptor Agonist, in Type 2 Diabetes Uncontrolled With Oral Antidiabetes Drugs: The FREEDOM-1 Trial.

OBJECTIVE: ITCA 650 (exenatide in osmotic mini-pump) continuously delivers exenatide subcutaneously for 3-6 months. Two doses of ITCA 650 were compared with placebo in patients with uncontrolled type 2 diabetes. RESEARCH DESIGN AND METHODS: This 39-week, phase 3, double-blind, placebo-controlled trial randomized 460 patients aged 18-80 years with glycated hemoglobin (HbA1c) 7.5-10% [58-86 mmol/mol] 1:1:1 to placebo, ITCA 650 40 µg/day, or ITCA 650 60 µg/day. Primary end point was change in HbA1c at 39 weeks. RESULTS: Least squares (LS) mean change from baseline HbA1c was -1.1% [-12.2 mmol/mol] and -1.2% [-13.2 mmol/mol] for ITCA 650 40 and 60 µg/day, respectively (P < 0.001 vs. placebo -0.1% [-1.3 mmol/mol]). In a prespecified analysis, greater HbA1c reductions occurred in patients not receiving sulfonylureas (SUs) versus those receiving SUs (-1.7% vs. -1.2% [-18.6 and -13.1 mmol/mol]). At week 39, HbA1c <7% [53 mmol/mol] was attained in 37%, 44%, and 9% of ITCA 650 40 µg/day, ITCA 650 60 µg/day, and placebo groups, respectively (P < 0.001 each dose vs. placebo). LS mean change from baseline body weight was -2.3 kg and -3.0 kg for ITCA 650 40 and 60 µg/day, respectively (P ≤ 0.015 vs. placebo -1.0 kg). Nausea was the most common adverse event (AE) and subsided over time. Discontinuation for gastrointestinal AEs occurred in 7.2% with ITCA and 1.3% with placebo. Most AEs associated with procedures to place and remove ITCA 650 were mild and transient. CONCLUSIONS: ITCA 650 significantly reduced HbA1c and weight compared with placebo and was well tolerated in patients with uncontrolled type 2 diabetes on oral antidiabetes medications.

Nucleotide-binding domains of cystic fibrosis transmembrane conductance regulator, an ABC transporter, catalyze adenylate kinase activity but not ATP hydrolysis.

The cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel in the ATP-binding cassette (ABC) transporter family. CFTR consists of two transmembrane domains, two nucleotide-binding domains (NBD1 and NBD2), and a regulatory domain. Previous biochemical reports suggest NBD1 is a site of stable nucleotide interaction with low ATPase activity, whereas NBD2 is the site of active ATP hydrolysis. It has also been reported that NBD2 additionally possessed adenylate kinase (AK) activity. Knowledge about the intrinsic biochemical activities of the NBDs is essential to understanding the Cl(-) ion gating mechanism. We find that purified mouse NBD1, human NBD1, and human NBD2 function as adenylate kinases but not as ATPases. AK activity is strictly dependent on the addition of the adenosine monophosphate (AMP) substrate. No liberation of [(33)P]phosphate is observed from the gamma-(33)P-labeled ATP substrate in the presence or absence of AMP. AK activity is intrinsic to both human NBDs, as the Walker A box lysine mutations abolish this activity. At low protein concentration, the NBDs display an initial slower nonlinear phase in AK activity, suggesting that the activity results from homodimerization. Interestingly, the G551D gating mutation has an exaggerated nonlinear phase compared with the wild type and may indicate this mutation affects the ability of NBD1 to dimerize. hNBD1 and hNBD2 mixing experiments resulted in an 8-57-fold synergistic enhancement in AK activity suggesting heterodimer formation, which supports a common theme in ABC transporter models. A CFTR gating mechanism model based on adenylate kinase activity is proposed.

Investigation of protein refolding using a fractional factorial screen: a study of reagent effects and interactions.

A recurring obstacle for structural genomics is the expression of insoluble, aggregated proteins. In these cases, the use of alternative salvage strategies, like in vitro refolding, is hindered by the lack of a universal refolding method. To overcome this obstacle, fractional factorial screens have been introduced as a systematic and rapid method to identify refolding conditions. However, methodical analyses of the effectiveness of refolding reagents on large sets of proteins remain limited. In this study, we address this void by designing a fractional factorial screen to rapidly explore the effect of 14 different reagents on the refolding of 33 structurally and functionally diverse proteins. The refolding data was analyzed using statistical methods to determine the effect of each refolding additive. The screen has been miniaturized for automation resulting in reduced protein requirements and increased throughput. Our results show that the choice of pH and reducing agent had the largest impact on protein refolding. Bis-mercaptoacetamide cyclohexane (BMC) and tris (2-carboxyethylphosphine) (TCEP) were superior reductants when compared to others in the screen. BMC was particularly effective in refolding disulfide-containing proteins, while TCEP was better for nondisulfide-containing proteins. From the screen, we successfully identified a positive synergistic interaction between nondetergent sulfobetaine 201 (NDSB 201) and BMC on Cdc25A refolding. The soluble protein resulting from this interaction crystallized and yielded a 2.2 Angstroms structure. Our method, which combines a fractional factorial screen with statistical analysis of the data, provides a powerful approach for the identification of optimal refolding reagents in a general refolding screen.