Effects of inhaled human insulin on airway lining fluid composition in adults with diabetes

Further experimentation of inhaled; LANTUS, ACTRAPID and HUMULIN with todays' production systems

BACKGROUND

Several aerosol production systems have been used for aerosol insulin production. However; since the first studies several new models of jet-nebulizers and ultrasound nebulizers have been introduced in the market.

MATERIALS AND METHODS

Three different models of jet-nebulizers (different brands, same properties) and three different ultrasound nebulizers (different brands, same properties). Six residual cups (2 small ≤ 6 ml and 3 large ≤ 8 ml) were used for the jet-nebulizers. The ultrasound nebulizers were used with their facemasks or with their inlets which were included in the purchase package.

RESULTS

Ultrasound nebulizers; LANTUS produces by far the lowest mean droplets (2.44) half the size of the other two drugs (4.43=4.97). GIMA nebulizer is the most efficient producing one third of the droplet size of SHIMED and one second of EASYNEB (2.06<3.15<6.62). Finally, the 4 ml loading concentration is more suitable for supporting the production of smaller droplets (3.65<4.24). Drugs and nebulizers act interactively yielding very large droplets when ACTRAPID and HUMULIN are administered in joint with SHIMED nebulizer (9.59=7.72). Jet-nebulizers; HUMULIN again is the least preferred insulin since it hardly reaches the low but equal performance of others at the loading level of 6 ml. Residual cups E and B produce uniquely lower mean droplets at loading level 6.

CONCLUSIONS

Ultrasound nebulizers; the best suggested combination should be LANTUS insulin, GIMA nebulizer administered at loading dose of 4 ml jet-nebulizers. A global review can give the best combination: the lowest mean droplets are produced when the drugs LANTUS (mostly) and ACTRAPID are administered, applying the SUNMIST nebulizer in concert with residual cup B at loading levels of 6 ml.

Clinical expert panel on monitoring potential lung toxicity of inhaled oligonucleotides: consensus points and recommendations

Oligonucleotides (ONs) are an emerging class of drugs being developed for the treatment of a wide variety of diseases including the treatment of respiratory diseases by the inhalation route. As a class, their toxicity on human lungs has not been fully characterized, and predictive toxicity biomarkers have not been identified. To that end, identification of sensitive methods and biomarkers that can detect toxicity in humans before any long term and/or irreversible side effects occur would be helpful. In light of the public's greater interests, the Inhalation Subcommittee of the Oligonucleotide Safety Working Group (OSWG) held expert panel discussions focusing on the potential toxicity of inhaled ONs and assessing the strengths and weaknesses of different monitoring techniques for use during the clinical evaluation of inhaled ON candidates. This white paper summarizes the key discussions and captures the panelists' perspectives and recommendations which, we propose, could be used as a framework to guide both industry and regulatory scientists in future clinical research to characterize and monitor the short and long term lung response to inhaled ONs.

Nanomedicine for treatment of diabetes in an aging population: state-of-the-art and future developments

Nowadays diabetes, especially type 2 diabetes (which is strongly related to the Western diet and life-style), has developed worldwide into an epidemic disease. Nanomedicine aims to provide novel tools for diagnosis, therapy and point-of-care management of patients. Several nanotechnological approaches were developed to improve life quality for patients with insulin-dependent diabetes. They facilitate blood glucose management by non-invasive glucose measurement as well as insulin administration mainly by delivering the fragile protein as protected and targeted formulation via nasal or oral route. In the present review the oral or nasal insulin delivery by polymeric nanoparticles is discussed with focus on physiological change either related to the disease, diabetes or age-related metabolic variations influencing insulin release and bioavailability. One critical point is that new generations of targeted nanoparticle based drugs are developed and optimized for certain metabolic conditions. These conditions may change with age or disease. The influence of age-related factors such as immaturity in very young age, metabolic and physiologic changes in old age or insufficient animal models are still under-investigated not only in nanomedicine but also generally in pharmacology. Summarizing it can be noted that the bioavailability of insulin administered via routes others than subcutaneously is comparably low (max. 60%). Moreover factors like changed gut permeability as described for diabetes type 1 or other metabolic peculiarities such as insulin resistance in case of type 2 diabetes also play a role in affecting the development of novel nanoparticulated drug preparations and can be responsible for unsuccessful translation of promising animal results into human therapy. In future insulin nanoparticle development for diabetes must consider not only requirements imposed by the drug but also metabolic changes inflicted by disease or by age. Moreover new approaches are required for prevention of the disease.

Pulmonary function over 2 years in diabetic patients treated with prandial inhaled Technosphere Insulin or usual antidiabetes treatment: a randomized trial

AIMS

Development of inhaled insulin has increased the need to understand its pulmonary safety. This study evaluated pulmonary function changes in diabetes patients receiving inhaled Technosphere Insulin (TI) or usual antidiabetes treatment (usual care).

METHODS

This randomized, open-label study was conducted at 220 sites (25 July 2005 to 29 August 2008). Pulmonary function tests [forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC), total lung capacity (TLC) and lung diffusion capacity for carbon monoxide (DL(CO))] were prospectively followed over 2 years in patients with type 1 or type 2 diabetes receiving TI (n = 730) or usual care (n = 824), along with a cohort without diabetes not receiving any specific therapy (n = 145).

RESULTS

Baseline demographics and pulmonary function were similar between diabetes treatment groups. Lung function declined from baseline in all groups. TI was non-inferior to usual care for mean change in FEV(1) from baseline to month 24 [mean (s.e.m.) 0.037 (0.0119) l; 95% CI 0.014 to 0.060] using mixed-model repeated-measure with a pre-specified non-inferiority margin of 50 ml/year. After a greater initial decline at month 3 with TI, rate of change (slope) in FEV(1), FVC and DL(CO) (months 3-24) was not statistically different between treatment groups. TI was well tolerated; no serious safety concerns emerged. The most common respiratory event associated with TI was mild, transient cough, occurring within minutes of inhalation.

CONCLUSIONS

Observed changes in lung function with TI were small, occurred early after therapy initiation, remained non-progressive over 2 years and were unlikely to be clinically meaningful.

Trough insulin levels in bronchoalveolar lavage following inhaled human insulin (Exubera) in patients with diabetes mellitus

BACKGROUND/AIM

There are few data regarding insulin levels in the lungs during diabetes therapy with inhaled insulin. We examined the disposition of inhaled human insulin (Exubera(®) [EXU] human insulin [recombinant DNA origin], Pfizer, New York, NY) in the lungs by measuring trough insulin levels in bronchoalveolar lavage (BAL) fluid after 12 weeks of EXU treatment.

METHODS

After a 4-week run-in period of subcutaneous insulin therapy, 24 subjects with type 1 diabetes mellitus (T1DM) and 26 with type 2 diabetes mellitus (T2DM) continued their basal insulin regimen and received premeal subcutaneous (SC) insulin for 13 weeks, followed by 12 weeks of premeal EXU. BAL was performed approximately 12 h after the last insulin dose at (1) baseline, (2) following SC insulin, and (3) following EXU.

RESULTS

Twenty patients with T1DM and 24 patients with T2DM completed all three bronchoscopies. BAL trough insulin levels were undetectable at baseline or following SC insulin. After EXU therapy, they increased to a median of 4.5 nM (1.6-9.0 nM) and 2.3 nM (0.5-9.4 nM) in T1DM and T2DM, respectively. BAL trough insulin levels did not correlate with treatment efficacy, adverse effects, plasma insulin levels, or changes in pulmonary function. A larger proportion of previous EXU doses was present in the BAL in patients with T1DM. We found no correlation between average daily insulin doses and BAL trough insulin levels.

CONCLUSIONS

BAL trough insulin increased following EXU therapy, but this increase did not correlate with other clinical or laboratory parameters, suggesting no significant biological action. Further studies are warranted to better understand inhaled insulin deposition and clearance and possible effects of increased insulin levels on the lungs.

Nanomedicine for treatment of diabetes in an aging population: state-of-the-art and future developments

Nowadays diabetes, especially type 2 diabetes (which is strongly related to the Western diet and life-style), has developed worldwide into an epidemic disease. Nanomedicine aims to provide novel tools for diagnosis, therapy and point-of-care management of patients. Several nanotechnological approaches were developed to improve life quality for patients with insulin-dependent diabetes. They facilitate blood glucose management by non-invasive glucose measurement as well as insulin administration mainly by delivering the fragile protein as protected and targeted formulation via nasal or oral route. In the present review the oral or nasal insulin delivery by polymeric nanoparticles is discussed with focus on physiological change either related to the disease, diabetes or age-related metabolic variations influencing insulin release and bioavailability. One critical point is that new generations of targeted nanoparticle based drugs are developed and optimized for certain metabolic conditions. These conditions may change with age or disease. The influence of age-related factors such as immaturity in very young age, metabolic and physiologic changes in old age or insufficient animal models are still under-investigated not only in nanomedicine but also generally in pharmacology. Summarizing it can be noted that the bioavailability of insulin administered via routes others than subcutaneously is comparably low (max. 60%). Moreover factors like changed gut permeability as described for diabetes type 1 or other metabolic peculiarities such as insulin resistance in case of type 2 diabetes also play a role in affecting the development of novel nanoparticulated drug preparations and can be responsible for unsuccessful translation of promising animal results into human therapy. In future insulin nanoparticle development for diabetes must consider not only requirements imposed by the drug but also metabolic changes inflicted by disease or by age. Moreover new approaches are required for prevention of the disease.

Inhaled insulin: too soon to be forgotten?

Inhalation is a potentially viable route of administration for numerous agents. In diabetes mellitus, the need for frequent injections to achieve ideal glycemic control remains a significant limitation for initiating and complying with insulin therapy in a large number of patients. To overcome this barrier, inhaled insulin was developed. The inhalation form of regular human insulin has been tested and administered in a large number of trials. Respiratory capacity was evaluated in patients with normal lung parenchyma in whom inhaled insulin was administered without complications. However, issues like cost, bulky device, fear for lung safety, and the small number of studies in subjects with underlying respiratory disease prevented widespread use of this new mode of delivery. In the present review, we will suggest a number of methods that could be applied in this form of administration to maximize drug absorption and fully exploit the advantages of this route of administration.

Inhaled insulin forms toxic pulmonary amyloid aggregates

It is well known that interfaces, such as polar-nonpolar or liquid-air, play a key role in triggering protein aggregation in vitro, in particular the aggregation of peptides and proteins with the predisposition of misfolding and aggregation. Here we show that the interface present in the lungs predisposes the lungs to form aggregation of inhaled insulin. Insulin inhalers were introduced, and a large number of diabetic patients have used them. Although inhalers were safe and effective, decreases in pulmonary capacity have been reported in response to inhaled insulin. We hypothesize that the lung air-tissue interface provides a template for the aggregation of inhaled insulin. Our studies were designed to investigate the harmful potential that inhaled insulin has in pulmonary tissue in vivo, through an amyloid formation mechanism. Our data demonstrate that inhaled insulin rapidly forms amyloid in the lungs causing a significant reduction in pulmonary air flow. Our studies exemplify the importance that interfaces play in protein aggregation in vivo, illustrating the potential aggregation of inhaled proteins and the formation of amyloid deposits in the lungs. These insulin deposits resemble the amyloid structures implicated in protein misfolding disorders, such as Alzheimer's and Parkinson's diseases, and could as well be deleterious in nature.

Assessment of long-term immunological and pulmonary safety of inhaled human insulin with up to 24 months of continuous therapy

BACKGROUND

This study was performed to characterize the long-term safety and efficacy of inhaled human insulin (EXU; Exubera * (insulin human [rDNA origin]) Inhalation Powder). * Pfizer Inc, New York, NY, USA.

SCOPE

Patients with type 1 or type 2 diabetes (N = 1290) who had successfully completed one of six controlled EXU open-label trials elected to receive open-label treatment with EXU for up to 3 years, after which they were randomized to discontinue EXU or to continue therapy for 6 months, then discontinue. Immunologic safety was assessed by insulin antibody (IAb) binding, and pulmonary safety was assessed by tests for forced expiratory volume in 1 second (FEV(1)) and carbon monoxide diffusing capacity (DL(CO)). In addition, changes over time in IAbs were compared with changes in FEV(1), DL(CO), hypoglycemia, and efficacy.

FINDINGS

Antibody binding increased in patients with either type 1 or type 2 diabetes after initiation of EXU and plateaued within 6-12 months (increases were higher in patients with type 1 diabetes than in patients with type 2 diabetes). Decreases in FEV(1) occurred primarily during the first 3-6 months of EXU therapy. Among adult patients in the All Subjects set, the mean (± SE) annualized rate of decline in FEV(1) was -0.053 ± 0.007 liters/year (95% CI, -0.065, -0.040) in adult patients with type 1 diabetes, and -0.076 ± 0.005 liters/year (95% CI, -0.085, -0.067) in patients with type 2 diabetes. Changes in DL(CO) occurred primarily during the first 3-6 months of EXU therapy. Among adult patients, in the All Subjects set, the mean (± SE) annual decline in DL(CO) was -0.738 ± 0.097 mL/min/mmHg/year (95% CI, -0.927, -0.548) and -0.688 ± 0.082 mL/min/mmHg/year (95% CI, -0.849, -0.527) in patients with type 1 and type 2 diabetes, respectively. Antibody binding did not correlate with changes in glycemic control, lung function, dose, or hypoglycemia. Following discontinuation of EXU, IAbs decreased to near baseline levels.

CONCLUSION

These results are consistent with other trials showing long-term maintenance of safety and efficacy of EXU despite insulin antibody formation and small treatment group differences in pulmonary function. A limitation of the study was the lack of a comparator therapy.