Will availability of inhaled human insulin (Exubera) improve management of type 2 diabetes? The design of the Real World trial

Can inhaled insulin be used for the treatment of diabetes mellitus?

Reluctance to start and adequately titrate subcutaneous insulin are major reasons why many patients with diabetes mellitus are insufficiently metabolically controlled. Pulmonary insulin administration has the advantage over subcutaneous insulin in that it is noninvasive, seems better accepted by the diabetic population and exerts equal efficacy in terms of glycemic control. As such, inhaled insulin has the potential to increase the diabetic (Type 2) patient's willingness to commence and adhere to insulin therapy. Inhaled insulin's short duration of action makes it suitable for prandial administration provided that basal insulin requirements are met by residual b-cell function, or by supplemental long-acting subcutaneous insulin. In clinical trials, inhaled insulin is comparable to short-acting subcutaneous insulin with regard to efficacy and hypoglycemic risk. Adverse effects associated with inhaled insulin include dry cough, which tends to diminish over time, a slight drop in pulmonary function that does not progress and is reversible in most patients if treatment is discontinued, and increased insulin antibody formation, albeit without clinical sequelae. Long-term safety remains an issue for a product intended to be used chronically for many years. Exubera((R)) was thus far the only inhaled insulin product to receive approval in the USA and Europe for use in adults with Type 1 or Type 2 diabetes, but was recently withdrawn from the market. At present it is unclear how this decision will affect programs from other companies with inhaled insulin products under development.

Designing "Real-World" trials to meet the needs of health policy makers at marketing authorization

OBJECTIVE

There is increasing interest in conducting "Real-World" trials that go beyond traditional assessment of efficacy and safety to examine market access and value for money questions before marketing authorization of a new pharmaceutical product or health technology. This commentary uses practical examples to demonstrate how high-quality evidence of the cost-effectiveness of an intervention may be gained earlier in the development process.

STUDY DESIGN

Issues surrounding the design and analysis of "Real-World" trials to demonstrate relative cost-effectiveness early in the life of new technologies are discussed. The modification of traditional phase III trial designs, de novo trial designs, the combination of trial-based and epidemiological data, and the use of simulation model-based approaches to address reimbursement questions are described.

RESULTS

Modest changes to a phase III trial protocol and case report form may be undertaken at the design stage to provide valid estimates of health care use and the benefits accrued; however, phase III designs often preclude "real-life" practice. Relatively small de novo trials may be used to address adherence to therapy or patient preference, although simply designed studies with active comparators enrolling large numbers of patients may provide evidence on long-term safety and rare adverse events.

CONCLUSIONS

Practical examples demonstrate that it is possible to provide high-quality evidence of the cost-effectiveness of an intervention earlier in the development process. Payers and decision makers should preferentially adopt treatments with such evidence than treatments for which evidence is lacking or of lower quality.

Assessing the impact of a new delivery method of insulin on glycemic control using a novel trial design

OBJECTIVE

The purpose of the trial was to examine the impact of inhaled human insulin (INH) on patient or physician willingness to adopt insulin after oral diabetes agent failure.

RESEARCH DESIGN AND METHODS

The EXPERIENCE trial was a one-year randomized controlled trial conducted at primary, secondary and tertiary care facilities in Europe and North America. The primary study endpoint was difference in glycated hemoglobin (A(1c)) between randomized groups at 26 weeks, and results from that phase have been reported previously. The present report concerns results from the second 26-week extension phase. We also consider the applicability of the design. The trial recruited 727 patients with type 2 diabetes mellitus who, prior to randomization, were using two or more oral diabetes agents and whose A(1c) was ≥ 8.0%. Patients were randomized to two treatment settings: Group 1 (usual care with the option of INH) or Group 2 (usual care only). Usual care included adjusting oral therapy (optimizing current regimen or adding/deleting agents) and/or initiating subcutaneous (SC) insulin.

RESULTS

At baseline, insulin was initiated by more (odds ratio [OR] 6.0;95% confidence interval [CI] 4.2 to 8.8; P < 0.0001) patients in Group 1 (86.2%; 76.7% INH plus 9.5% SC) than in Group 2 (50.7%; SC insulin only). The largest reduction from baseline in A(1c) was in Group 1 (-2.0 ± 1.2%) at Week 12 and in Group 2 (-1.8 ± 1.3%) at Week 26 (P = 0.003). At 52 weeks, 79.8% were on insulin in Group 1 (67.4% INH; 12.4% SC) vs 58.1% (SC only) in Group 2, and mean (SD) changes in A(1c) from baseline were -1.9% (1.2%) and -1.8% (1.3%) in Groups 1 and 2, respectively (P = 0.05). Hypoglycemic event rates per patient month were 0.3 and 0.1 in Groups 1 and 2, respectively (P < 0.0001).

CONCLUSION

The EXPERIENCE trial showed that novel delivery technology can accelerate the adoption of insulin although some attenuation of differences is observed over time. And further, that this was achieved in a population of patients who appeared more ready to move to insulin therapy than observed in standard clinical practice, and a group of physicians who appeared more ready to adopt INH than the majority of physicians.

A review on the actual trends of insulin treatment in elderly with diabetes

The diabetes of the elderly subjects has two forms: diabetes of long duration, manifesting itself in younger or medium ages, and senile diabetes, appearing above the age of 65 years. The diabetes of the elderly has usually only modest symptoms: it is not ketosic, but in spite of this, in order to avoid the chronic-degenerative complications, it is important to maintain a good, even if not an optimal compensation. The therapeutic intervention cannot neglect a correct alimentary regime and a programmed physical activity in correlation with the clinical conditions of the patient. If the compensation is not achieved only with these tools, one can add oral antidiabetic treatments. In the elderly patients we usually observe primary or secondary failure of the oral antidiabetic treatments, and in such context we have to apply insulin treatment, even in cases of moderate glycometabolic decompensations. While we are waiting for the gene-therapy or the inhalatory insulin preparations, actually there are at disposal only the insulin analogs in rapid, slow and mixed forms. We propose two treatment schemes: (i) The first one consists of three administrations of rapid insulin with the meals, and on dose of slow insulin 2h after the last meal in the evening. (ii) The second scheme consists of one administration of rapid insulin at lunch, one administration of mixed insulin at dinner, with the addition of oral antidiabetics of peripheric action, in the morning and the evening. A better compliance can be obtained, being a fundamental aspect in the elderly diabetics, and a reduction of the number and severity of the hypoglycemia, which are the most important aspects in the elderly diabetes.

The effect of the availability of inhaled insulin on glycaemic control in patients with Type 2 diabetes failing on oral therapy: the evaluation of Exubera as a therapeutic option on insulin initiation and improvement in glycaemic control in clinical practice (EXPERIENCE) trial

AIM

To examine the impact of inhaled human insulin (Exubera, EXU) on patient or physician willingness to adopt insulin after oral glucose-lowering agent failure.

METHODS

During a randomized controlled trial in primary, secondary and tertiary care in Europe and North America, 739 patients using >or= 2 oral glucose-lowering agents with glycated haemoglobin (HbA(1c)) >or= 8.0% were assigned to two treatment groups: Group 1 (standard care with the option of EXU) or Group 2 (standard care only). Standard care included adjusting oral therapy (optimizing current regimen or adding/omitting agents) and/or initiating subcutaneous (s.c.) insulin. The primary endpoint was difference in HbA(1c) between randomized groups at 26 weeks. Secondary outcomes included differences in the rate of uptake of insulin therapy, proportion achieving satisfactory glycaemic control, treatment satisfaction and safety outcomes.

RESULTS

At baseline, insulin was initiated by more [odds ratio 6.0; 95% confidence interval (CI) 4.2 to 8.8; P < 0.0001] patients in Group 1 (86.2%; 76.7% EXU plus 9.5% s.c.) than Group 2 (50.7%; s.c. insulin only). At 26 weeks, mean (sd) changes in HbA(1c) from baseline were -2.0% (1.2%) and -1.7% (1.3%) in Groups 1 and 2, respectively, a difference of -0.2% (95% CI: -0.1% to -0.4%; P = 0.004). In Group 1, 45% of patients achieved an HbA(1c)<or= 7.0% by 26 weeks compared with 39% in Group 2 (P = 0.02).

CONCLUSION

The availability of EXU may increase initiation of insulin, thereby contributing to improved overall glycaemic control in patients with Type 2 diabetes inadequately controlled on two or more oral glucose-lowering agents.

AIR Inhaled Insulin System: a novel insulin-delivery system for patients with diabetes

Over time, most patients with Type 2 diabetes require insulin-replacement therapy to attain and sustain the increasingly stringent glycemic goals. Initiation of subcutaneous insulin may be delayed due to patient or provider resistance. This delay may increase the risk of complications from long-term hyperglycemia. The development of inhaled insulin-delivery systems has been pursued to facilitate earlier initiation and optimization of insulin therapy to achieve better treatment outcomes. The AIR((R)) Inhaled Insulin System utilizes relatively large, low-density particles, allowing efficient drug delivery to the deep lung from a simple inhaler. In clinical studies it has provided similar postprandial glycemic control compared with subcutaneously injected, short-acting insulin, and was preferred by more patients. The purpose of this article is to describe the AIR Inhaled Insulin System, provide an overview of other insulin-delivery systems and discuss future strategies for the treatment of diabetes.

Inhaled insulin

Inhaled insulin has attractive pharmacodynamic properties with a fast onset of action which should lead to improved postprandial blood glucose concentrations. Comparisons with regular subcutaneous (sc) insulin in clinical studies, however, showed lower fasting blood glucose concentrations. Overall, clinical efficacy of inhaled insulin was comparable to that of regular sc insulin. Treatment with inhaled insulin was safe and well tolerated, with slight and reversible changes in lung function parameters and a rise in insulin antibodies (not associated with any clinical or safety parameters) as main adverse effects. Treatment satisfaction in open-label studies was higher with inhaled than with sc insulin, indicating that inhaled insulin might help to overcome one of the major hurdles of diabetes therapy, i.e. a timely initiation of insulin therapy. The first inhaled insulin formulation was approved in the US and Europe in January 2006, but some countries granted reimbursement only for selected patients, or did not reimburse treatment with inhaled insulin at all because of the high treatment costs. These are due to the rather low bioavailability of approximately 8-15%. Therefore, further research is needed to improve the bioavailability of inhaled insulin: e.g. through optimization of the inhaler, the insulin formulation, or the inhalation technique. In view of the potential for further improvement, inhaled insulin may become a very attractive alternative to sc insulin, in particular in patients in whom insulin therapy has to be initiated and/or intensified.

The AIR inhaled insulin system: system components and pharmacokinetic/glucodynamic data

The diabetes epidemic and lack of adequate glycemic control in patients with diabetes emphasize the need for alternative diabetes treatment strategies. Although many new compounds have been developed, insulin remains the most potent agent for controlling glycemia. Inhaled insulin systems have been developed to alleviate the fear of insulin injections and to improve the convenience of insulin administration. The AIR Inhaled Insulin System being developed by Eli Lilly (Indianapolis, IN) and Alkermes (Cambridge, MA) uses AIR particle technology to deliver dry powder insulin to the deep lung. Pharmacokinetic and glucodynamic data in Phase 1 clinical trials have demonstrated that AIR Insulin is rapidly absorbed with prolonged insulin exposure and action compared to insulin lispro. AIR Insulin has also been shown to have dose equivalence and dose reproducibility across a range of doses, and it has been shown that three inhalations of the 2 U-equivalent dose can be interchanged with one 6 U-equivalent dose. A Phase 2 study demonstrated preference for AIR Insulin over subcutaneous injectable insulins, and a recent study reported that the system is easy to teach and use. Several Phase 3 studies are currently underway to further investigate the safety and efficacy and to evaluate the system's intention to meet provider and patient expectations.

Alternatives routes of insulin delivery

Optimal glycaemic control is necessary to prevent diabetes-related complications. An intensive treatment, which could mimic physiological insulin secretion, would be the best one. However subcutaneous insulin treatment is not physiologic and represents a heavy burden for patients with type 1 and type 2 diabetes mellitus. Consequently, more acceptable, at least as effective, alternative routes of insulin delivery have been developed over the past years. Up to now, only pulmonary administration of insulin (inhaled insulin) has become a feasible alternative to cover mealtime insulin requirements and one of the various administration systems was recently approved for clinical use in Europe and the United States. But, due to advances in technology, other routes, such as transdermal or oral (buccal and intestinal) insulin administration, could become feasible in a near future, and they could be combined together to offer non-invasive, efficacious and more physiological way of insulin administration to patients with diabetes.