A co-formulation of pramlintide and insulin A21G (ADO09) improves postprandial glucose and short-term control of mean glucose, time in range, and body weight versus insulin aspart in adults with type 1 diabetes

AIM

Pramlintide improves postprandial glucose but requires additional injections. We investigated the pharmacokinetics/pharmacodynamics, efficacy and safety of ADO09, pramlintide/insulin A21G co-formulation, in type 1 diabetes (T1D).

MATERIALS AND METHODS

This double-blinded, randomized, two-period cross-over study compared prandial administration of ADO09 or insulin aspart over 24 days in T1D using either ≤40 U bolus insulin per day [low-dose group (LD), n = 28] or 40-75 U [high-dose group (HD), n = 16]. Glycaemic responses through continuous glucose monitoring, and pharmacokinetics/pharmacodynamics profiles following mixed-meal-tolerance tests were evaluated at baseline and at the end of treatment.

RESULTS

Glucose increments from 0 to 4 h after mixed-meal-tolerance test (primary endpoint) were 39% (not statistically significantly) lower with ADO09 in the low-dose group and 69% lower in the high-dose group. Mean continuous glucose monitoring glucose during ambulatory treatment was lower with ADO09 than with aspart (LD: -8.2 ± 7.9 mg/dl, p = .0001; HD: -7.0 ± 10 mg/ml, p = .0127), and time-in-range (70-180 mg/dl) improved (LD: +4%, p = .0134; HD: +4%, p = .0432). Body weight declined significantly with ADO09 (LD: -0.8 kg; HD: -1.6 kg). Hypoglycaemic events were slightly more frequent with ADO09 versus aspart (LD: 142 vs. 115; HD: 96 vs. 79). Gastrointestinal events occurred more frequently with ADO09 but were generally transient, and no other safety signals were identified.

CONCLUSIONS

In comparison with aspart, ADO09 was well tolerated and effective in T1D across a wide range of dosage, significantly improving the average blood glucose level and body weight during 24 days of ambulatory treatment. Meal test profiles confirmed improvement of glycaemic patterns and other responses with ADO09.

ADO09, a co-formulation of the amylin analogue pramlintide and the insulin analogue A21G, lowers postprandial blood glucose versus insulin lispro in type 1 diabetes

AIM

To compare the safety, pharmacokinetics and pharmacodynamics of ADO09 with insulin lispro (Lispro) and separate subcutaneous injections of human insulin and pramlintide (Ins&Pram) in 24 subjects with type 1 diabetes.

METHODS

At three dosing visits, participants received single doses of ADO09, Ins&Pram or Lispro immediately before eating a standardized mixed meal together with 1 g of acetaminophen, which was used as a surrogate marker to evaluate the kinetics of gastric emptying. Premeal blood glucose was adjusted to 126 mg/dL ± 10% by means of insulin and glucose infusions. The insulin dose was 7.5 U and the pramlintide dose was 45 μg. Blood glucose, glucagon and acetaminophen concentrations were assessed as pharmacodynamic endpoints; insulin and pramlintide concentrations were analysed as pharmacokinetic endpoints, and safety and tolerability were assessed.

RESULTS

Compared with Lispro, ADO09 reduced postprandial blood glucose (ppBG) excursions by more than 95% in the first hour postmeal (mean ± SD ∆AUC BG 0-1 h: 1.4 ± 9.9 mg*h/dL vs. 43.5 ± 15.3 mg*h/dL; p < .0001). Maximum ppBG was significantly improved with ADO09 (∆BGmax 87.0 ± 35.5 mg/dL) versus both Lispro (109.2 ± 31.1 mg/dL; p = .0133) and Ins&Pram (109.4 ± 44.3 mg/dL; p = .0357). Gastric emptying with ADO09 was similar to Ins&Pram and significantly slower than with Lispro. All treatments were well tolerated and both adverse events and hypoglycaemic events were rare during the meal test procedure.

CONCLUSION

ADO09 was well tolerated and markedly reduced ppBG compared with Lispro. ADO09 formulation was generally similar to the separate administration of insulin and pramlintide, except for a better BG level in the 4-8 h interval postmeal. These positive results warrant further investigations with ADO09.

Better glycaemic control with BioChaperone glargine lispro co-formulation than with insulin lispro Mix25 or separate glargine and lispro administrations after a test meal in people with type 2 diabetes

Because of its physico-chemical properties, insulin glargine is usually not mixable with rapid insulins. BioChaperone BC147 is a polyanionic amphiphilic polymer, solubilizing insulin glargine at neutral pH, and thus enabling stable glargine formulation with fast-acting insulin lispro (BioChaperone glargine lispro co-formulation [BC Combo]). We investigated pharmacokinetic (PK) endpoints and postprandial glucose (PPG) control after administration of BC Combo (75% insulin glargine, 25% insulin lispro), insulin lispro Mix25 (LMix) and separate injections of insulins glargine (75% total dose) and lispro (25% total dose [G + L]) immediately before ingestion of a mixed meal in people with type 2 diabetes mellitus (T2DM), using a randomized, double-blind, double-dummy crossover study design. Participants received individualized bolus doses (mean 0.62 U/kg) of BC Combo, LMix or G + L, together with a solid mixed meal (610 kcal, 50% carbohydrate, 30% fat, 20% protein). Insulin dosages were kept constant for each study day. Thirty-nine participants with T2DM (mean ± SD age and glycated haemoglobin 60.8 ± 7.5 years and  64 ± 6 mmol/mol, respectively) were randomized. BC Combo improved the predefined primary endpoint, early PPG control, compared to LMix (incremental area under the blood glucose concentration-time curve from 0 to 2 hours after the meal [ΔAUC_BG,0-2h ] reduction of 18%; P = 0.0009) and G + L (ΔAUC_BG,0-2h reduction of 10%; P = 0.0450). The number of mealtime hypoglycaemic episodes per participant was lower with BC Combo (22 episodes in 14 participants) compared to LMix (43 episodes in 20 participants; P = 0.0028), but not significantly different from G + L (28 episodes in 19 participants; P = 0.2523). BC Combo demonstrated superior early PPG control with fewer hypoglycaemic episodes compared to LMix and superior early PPG control compared to separate G + L administrations.

BioChaperone Lispro versus faster aspart and insulin aspart in patients with type 1 diabetes using continuous subcutaneous insulin infusion: A randomized euglycemic clamp study

We investigated the pharmacodynamics (PD) and pharmacokinetics (PK) of BioChaperone insulin Lispro (BCLIS), faster insulin aspart (FIA) and insulin aspart (ASP) in patients with type 1 diabetes using an insulin pump. In this randomized, double-blind, three-way crossover glucose clamp study, 43 patients received a bolus dose of each insulin (0.15 U/kg) in addition to a basal rate (0.01 U/kg/h), delivered via an insulin pump. With BCLIS, the AUC-GIR,0-60 minutes (primary endpoint) was improved compared to ASP (least square means ratio, 1.63; 95% CI, 1.44-1.88; P < 0.0001) and was similar compared to FIA (least square means ratio, 1.06; 95% CI, 0.94-1.18; P = 0.4609). BCLIS showed faster-on PD (t_{early0.5GIRmax} ) than ASP and faster-off PD (t_{late0.5GIRmax} ) than both FIA and ASP. BCLIS also demonstrated significantly higher early exposure (AUCins, 0-60 minutes) and lower late exposure (AUCins,120-600 minutes) than both other insulins. In patients with type 1 diabetes using an insulin pump, BCLIS better mimics prandial insulin secretion and action than ASP and shows a faster off-PD than FIA.

Ultra-rapid BioChaperone Lispro improves postprandial blood glucose excursions vs insulin lispro in a 14-day crossover treatment study in people with type 1 diabetes

AIM

To investigate the safety and efficacy of BioChaperone Lispo (BCLIS), an ultra-rapid formulation of insulin lispro (LIS) in people with type 1 diabetes.

MATERIALS AND METHODS

In this randomized, double-blind study, participants self-administered individualized bolus doses of BCLIS or LIS during two 14-day periods in a crossover fashion. Postprandial blood glucose (BG) was assessed after individualized solid mixed meal tests (MMTs) (50% carbohydrate, 29% fat, 21% protein), with additional randomization for the sequence of timing of insulin administration, immediately (t0), 15 minutes before (t - 15) and 15 minutes after (t + 15) meal start on days 1, 2 and 3, and with t0 administration on day 14. Pharmacokinetic (PK) variables were assessed for t0 MMTs. Participants also used individualized BCLIS or LIS doses immediately before meals during two 10-day outpatient periods with an unchanged basal insulin regimen.

RESULTS

Overall, 35 participants completed both treatment periods. In MMTs with t0 administration, the higher early postprandial PK exposure of BCLIS led to significant reductions in 1- to 2-hour postprandial BG excursions by 30% to 40% vs LIS and the accelerated absorption and action of BCLIS persisted over 14 days. There was no difference in glucose excursion over the full 360-minute postprandial period. Postprandial BG control was similar between BCLIS injected at t + 15 and LIS injected at t0. BCLIS was shown to have safety and tolerability similar to LIS. No injection site reactions occurred with BCLIS.

CONCLUSIONS

BCLIS was well tolerated and safe over 14 days of treatment and significantly improved postprandial BG vs LIS when administered at mealtime.

Structural basis of DNA replication origin recognition by an ORC protein

DNA replication in archaea and in eukaryotes share many similarities. We report the structure of an archaeal origin recognition complex protein, ORC1, bound to an origin recognition box, a DNA sequence that is found in multiple copies at replication origins. DNA binding is mediated principally by a C-terminal winged helix domain that inserts deeply into the major and minor grooves, widening them both. However, additional DNA contacts are made with the N-terminal AAA+ domain, which inserts into the minor groove at a characteristic G-rich sequence, inducing a 35 degrees bend in the duplex and providing directionality to the binding site. Both contact regions also induce substantial unwinding of the DNA. The structure provides insight into the initial step in assembly of a replication origin and recruitment of minichromosome maintenance (MCM) helicase to that origin.

Biochemical analysis of a DNA replication origin in the archaeon Aeropyrum pernix

We have characterised the interaction of the Aeropyrum pernix origin recognition complex proteins (ORC1 and ORC2) with DNA using DNase I footprinting. Each protein binds upstream of its respective gene. However, ORC1 protein alone interacts more tightly with an additional region containing multiple origin recognition box (ORB) sites that we show to be a replication origin. At this origin, there are four ORB elements disposed either side of an A+T-rich region. An ORC1 protein dimer binds at each of these ORB sites. Once all four ORB sites have bound ORC1 protein, there is a transition to a higher-order assembly with a defined alteration in topology and superhelicity. Furthermore, after this transition, the A+T-rich region becomes sensitive to digestion by DNase I and P1 nuclease, revealing that the transition promotes distortion of the DNA in this region, presumably as a prelude to loading of MCM helicase.

Crystal structure of RecBCD enzyme reveals a machine for processing DNA breaks

RecBCD is a multi-functional enzyme complex that processes DNA ends resulting from a double-strand break. RecBCD is a bipolar helicase that splits the duplex into its component strands and digests them until encountering a recombinational hotspot (Chi site). The nuclease activity is then attenuated and RecBCD loads RecA onto the 3' tail of the DNA. Here we present the crystal structure of RecBCD bound to a DNA substrate. In this initiation complex, the DNA duplex has been split across the RecC subunit to create a fork with the separated strands each heading towards different helicase motor subunits. The strands pass along tunnels within the complex, both emerging adjacent to the nuclease domain of RecB. Passage of the 3' tail through one of these tunnels provides a mechanism for the recognition of a Chi sequence by RecC within the context of double-stranded DNA. Gating of this tunnel suggests how nuclease activity might be regulated.

The β-Thymosin/WH2 Domain

The widespread beta-thymosin/WH2 actin binding domain has versatile regulatory properties in actin dynamics and motility. beta-thymosins (isolated WH2 domain) maintain monomeric actin in a "sequestered" nonpolymerizable form. In contrast, when repeated in tandem or inserted in modular proteins, the beta-thymosin/WH2 domain promotes actin assembly at filament barbed ends, like profilin. The structural basis for these opposite functions is addressed using ciboulot, a three beta-thymosin repeat protein. Only the first repeat binds actin and possesses the function of ciboulot. The region that shows the strongest interaction with actin is an amphipathic N-terminal alpha helix, present in all beta-thymosin/WH2 domains, which recognizes the ATP bound actin structure and uses the shear motion of actin linked to ATP hydrolysis to control polymerization. Crystallographic ((1)H, (15)N), NMR, and mutagenetic data reveal that the weaker interaction of the C-terminal region of beta-thymosin/WH2 domain with actin accounts for the switch in function from inhibition to promotion of actin assembly.

Mechanism of neutralization of influenza virus infectivity by antibodies

We have determined the mechanism of neutralization of influenza virus infectivity by three antihemagglutinin monoclonal antibodies, the structures of which we have analyzed before as complexes with hemagglutinin. The antibodies differ in their sites of interaction with hemagglutinin and in their abilities to interfere in vitro with its two functions of receptor binding and membrane fusion. We demonstrate that despite these differences all three antibodies neutralize infectivity by preventing virus from binding to cells. Neutralization occurs at an average of one antibody bound per four hemagglutinins, a ratio sufficient to prevent the simultaneous receptor binding of hemagglutinins that is necessary to attach virus to cells.

Crystal structure of vesicular stomatitis virus matrix protein

The vesicular stomatitis virus (VSV) matrix protein (M) interacts with cellular membranes, self-associates and plays a major role in virus assembly and budding. We present the crystallographic structure, determined at 1.96 A resolution, of a soluble thermolysin resistant core of VSV M. The fold is a new fold shared by the other vesiculovirus matrix proteins. The structure accounts for the loss of stability of M temperature-sensitive mutants deficient in budding, and reveals a flexible loop protruding from the globular core that is important for self-assembly. Membrane floatation shows that, together with the M lysine-rich N-terminal peptide, a second domain of the protein is involved in membrane binding. Indeed, the structure reveals a hydrophobic surface located close to the hydrophobic loop and surrounded by conserved basic residues that may constitute this domain. Lastly, comparison of the negative-stranded virus matrix proteins with retrovirus Gag proteins suggests that the flexible link between their major membrane binding domain and the rest of the structure is a common feature shared by these proteins involved in budding and virus assembly.

Cleavage of vesicular stomatitis virus matrix protein prevents self-association and leads to crystallization

The matrix protein (M) of vesicular stomatitis virus is responsible for the budding of newly formed virions out of host cells. In vitro, it has been shown to self-associate, a property that may be related to the role of M in virus assembly but also prevents crystallization. Using limited proteolysis by thermolysin, we have isolated and characterized two soluble fragments of the protein that remain noncovalently associated. The digestion product does not self-associate nor is it recruited in aggregates formed by intact M molecules. These results identify a peptide, located at the surface of the protein and disorganized by thermolysin cleavage, responsible for M self-association. The thermolysin-resistant core of M has been crystallized and the crystals diffract to 2-A resolution.