Acromegaly Disease Control Maintained After Switching From Injected Somatostatin Receptor Ligands to Oral Paltusotine.

CONTEXT: Paltusotine is a nonpeptide selective somatostatin receptor 2 agonist in development as once-daily oral treatment for acromegaly. OBJECTIVE: To evaluate the efficacy and safety of paltusotine in the treatment of patients with acromegaly previously controlled with injected somatostatin receptor ligands (SRLs). METHODS: This phase 3, randomized, double-blind, placebo-controlled trial enrolled adults with acromegaly who had insulin-like growth factor I (IGF-I) ≤1.0 times the upper limit of normal (×ULN) while receiving a stable dose of depot octreotide or lanreotide. Patients were switched from injected SRLs and randomized to receive paltusotine or placebo orally for 36 weeks. The primary endpoint was proportion of patients maintaining IGF-I ≤1.0×ULN. Secondary endpoints were change in IGF-I level, change in Acromegaly Symptom Diary (ASD) score, and maintenance of mean 5-sample growth hormone (GH) <1.0 ng/mL. RESULTS: The primary endpoint was met: 83.3% (25/30) of patients receiving paltusotine and 3.6% (1/28) receiving placebo maintained IGF-I ≤1.0×ULN (odds ratio: 126.53; 95% CI: 13.73, >999.99; P<.0001). Paltusotine was also superior to placebo for all secondary endpoints: mean (±SE) change in IGF-I of 0.04±0.09×ULN versus 0.83±0.1×ULN (P<.0001); mean (±SE) change in ASD score of -0.6±1.5 versus 4.6±1.6 (P=.02); mean GH maintained at <1.0 ng/mL in 20/23 (87.0%) versus 5/18 (27.8%) patients (odds ratio: 16.61; 95% CI: 2.86, 181.36; P=.0003). The most common adverse events were acromegaly symptoms and gastrointestinal effects characteristic of SRLs. CONCLUSION: Replacement of injected SRLs by once-daily oral paltusotine was effective in maintaining both biochemical and symptom control in patients with acromegaly and was well tolerated.

Development and evaluation of the Acromegaly Symptom Diary.

BACKGROUND: Patient-reported outcome (PRO) measures are important to consider when evaluating treatments, yet there are no PRO measures for patients with acromegaly that have been developed in accordance with US Food and Drug Administration guidance. Acromegaly is a rare, chronic condition caused by hypersecretion of growth hormone. Disease activity is monitored by measurement in serum of growth hormone and insulin-like growth factor-I. The objectives of this research were to develop the Acromegaly Symptom Diary (ASD), establish a scoring algorithm, and evaluate the psychometric measurement properties of the ASD. METHODS: Semistructured interviews consisting of concept elicitation and cognitive debriefing components were conducted with 16 adult participants with acromegaly. The concept elicitation component identified symptoms important to individuals with acromegaly. The cognitive debriefing component gathered information about the participants' experience with each proposed item of the ASD, their thought process for answering each question, and their interpretation of the items. The psychometric properties of the draft ASD were then evaluated using data from the ACROBAT Evolve (NCT03792555; n = 13) and ACROBAT Edge (NCT03789656; n = 47) clinical trials. RESULTS: The 16 participants from the interviews described ongoing symptoms, with the most frequently reported being joint pain (n = 13) and fatigue (n = 12), followed by swelling (n = 8), headache (n = 7), and mood swings (n = 6), and were able to interpret and understand the ASD items and had no issues with the 24-hour recall period. From data collected in the clinical studies, the psychometric properties of internal consistency (0.91 - 0.80), test-retest reliability with item-level and total ASD scores (> 0.70), baseline construct validity (r ≥ |0.38|) across scales, and responsiveness to change (r = 0.52-0.56) were supported for the ASD. The proposed preliminary threshold range to characterize a meaningful change from the patients' perspective for the ASD total is a 4- to 6-point change for improvement or worsening out of a total score of 70. CONCLUSION: These findings provide qualitative and quantitative evidence to support the ASD as fit for the purpose of evaluating the symptom experience of patients with acromegaly in clinical trials.

ACROBAT Edge: Safety and Efficacy of Switching Injected SRLs to Oral Paltusotine in Patients With Acromegaly.

CONTEXT: Paltusotine is a once-daily, oral, nonpeptide small-molecule somatostatin receptor type 2 (SST2) agonist in clinical development for treatment of acromegaly. OBJECTIVE: This work aimed to evaluate change in insulin-like growth factor I (IGF-I) levels in patients switched from octreotide long-acting release or lanreotide depot monotherapy to paltusotine. METHODS: A phase 2, open-label, prospective, multicenter, multinational, nonrandomized, single-arm exploratory study was conducted in which dosage uptitrations were performed in a double-blinded manner. At 26 global sites, patients with acromegaly switched to paltusotine from injected somatostatin receptor ligand (SRL)-based therapy. Patients received 13-week treatment with once-daily oral paltusotine (10-40 mg/d). The primary end point was change from baseline to week 13 in IGF-I for patients who switched from long-acting octreotide or lanreotide depot monotherapy to paltusotine (group 1). All patients underwent a 4-week paltusotine washout at end of treatment period (wk 13-17). IGF-I, growth hormone (GH), patient-reported outcome, and safety data were collected. RESULTS: Forty-seven patients enrolled. In group 1 (n = 25), IGF-I and GH showed no significant change between SRL baseline and end of paltusotine treatment at week 13 (median change in IGF-I = -0.03×upper limit of normal [ULN]; P = .6285; GH = -0.05 ng/mL; P = .6285). IGF-I and GH rose significantly in the 4 weeks after withdrawing paltusotine (median change in IGF-I = 0.55×ULN; P < .0001 [median increase 39%]; GH = 0.72 ng/mL; P < .0001 [109.1% increase]). No patients discontinued because of adverse events (AE); no treatment-related serious AEs were reported. CONCLUSION: These results suggest once-daily oral paltusotine was effective in maintaining IGF-I values in patients with acromegaly who switched from injected SRLs. Paltusotine was well tolerated with a safety profile consistent with other SRLs.

Paltusotine, a novel oral once-daily nonpeptide SST2 receptor agonist, suppresses GH and IGF-1 in healthy volunteers.

PURPOSE: Evaluate the pharmacodynamics, pharmacokinetics, and safety of paltusotine, an orally bioavailable, nonpeptide, somatostatin receptor subtype 2 (SST2) agonist being developed for the treatment of acromegaly and neuroendocrine tumors. METHODS: A randomized, double-blind, placebo-controlled, single center, single and multiple ascending dose phase 1 study was conducted in healthy male volunteers who received (i) single-dose of oral paltusotine 1.25, 2.5, 5, 10, and 20 mg (solution); and 40 and 60 mg (capsules) or (ii) multiple-dose oral paltusotine capsules once daily 5 mg (× 7 days), 10, 20, and 30 mg (× 10 days). Main outcome measures were pharmacodynamics (changes in growth hormone-releasing hormone [GHRH] stimulated growth hormone [GH] and insulin-like growth factor 1 [IGF-1]), pharmacokinetics, safety, and tolerability. RESULTS: Single-dose cohorts: n = 41 active, n = 14 placebo. Multiple-dose cohorts: n = 24 active, n = 12 placebo. Paltusotine was well tolerated, orally bioavailable, associated with increased plasma concentrations to doses up to 40 mg, and was eliminated with a half-life of approximately 30 h. Single-dose paltusotine 1.25 to 20 mg suppressed GHRH-stimulated GH secretion by 44% to 93% compared to 15% with placebo. Multiple-dose paltusotine 5 to 30 mg administered once daily for 10 days suppressed IGF-1 by 19% to 37% compared to an increase of 2.4% with placebo. CONCLUSIONS: Paltusotine suppresses GH and IGF-1 in a dose-dependent fashion, with a safety profile similar to currently approved SST2 receptor ligands. Paltusotine is a promising once-daily oral nonpeptide SST2 agonist candidate for managing acromegaly and neuroendocrine tumors. TRIAL REGISTRATION: NCT03276858, registered September 8, 2017, retrospectively registered.

Five-year Estimated Glomerular Filtration Rate in Patients With Hypoparathyroidism Treated With and Without rhPTH(1-84).

CONTEXT: Chronic hypoparathyroidism (HypoPT) is conventionally managed with oral calcium and active vitamin D. Recombinant human parathyroid hormone (1-84) (rhPTH[1-84]) is a therapy targeting the pathophysiology of HypoPT by replacing parathyroid hormone. OBJECTIVE: To compare changes in the estimated glomerular filtration rate (eGFR) in patients with chronic HypoPT receiving or not receiving rhPTH(1-84) during a 5-year period. DESIGN/SETTING: A retrospective analysis of patients with chronic HypoPT treated with or without rhPTH(1-84). PATIENTS: Sixty-nine patients with chronic HypoPT from 4 open-label, long-term trials (NCT00732615, NCT01268098, NCT01297309, and NCT02910466) composed the rhPTH(1-84) cohort and 53 patients with chronic HypoPT not receiving rhPTH(1-84) from the Geisinger Healthcare Database (01/2004-06/2016) composed the historical control cohort. INTERVENTIONS: The rhPTH(1-84) cohort (N = 69) received rhPTH(1-84) therapy; the historical control cohort (N = 53) did not receive rhPTH(1-84). MAIN OUTCOME MEASURES: Changes in eGFR from baseline during a 5-year follow-up were examined in multivariate regression analyses. RESULTS: At baseline, demographic characteristics and eGFR were similar between cohorts, though the proportions with diabetes and cardiac disorders were lower in the rhPTH(1-84) cohort. At the end of follow-up, mean eGFR increased by 2.8 mL/min/1.73 m2 in the rhPTH(1-84) cohort, while mean eGFR fell by 8.0 mL/min/1.73 m2 in the control cohort. In the adjusted model, the difference in the annual eGFR change between the rhPTH(1-84) cohort and the control cohort was 1.7 mL/min/1.73 m2 per year (P = 0.009). CONCLUSIONS: Estimated glomerular filtration rate was preserved for over 5 years among patients with chronic HypoPT receiving rhPTH(1-84) treatment, contrasting with an eGFR decline among those not receiving rhPTH(1-84).

Development of a Patient-Reported Outcome Measure for Chronic Hypoparathyroidism.

INTRODUCTION: A patient-reported outcome (PRO) measure specific to chronic hypoparathyroidism is lacking to facilitate the evaluation of treatment. A PRO measure that followed the recommendations of the US Food and Drug Administration (FDA) PRO guidance was created to address key hypoparathyroidism symptoms. METHODS: A literature review was conducted to identify symptoms of hypoparathyroidism and any existing PRO measures appropriate for evaluating these symptoms, followed by concept elicitation interviews involving six individuals with hypoparathyroidism. On the basis of the results of the literature review and interviews, a draft item pool was developed and refined through two sets of cognitive debriefing interviews with six additional patients. A translatability assessment was also conducted to evaluate concepts, phrases, or components of the items that could be problematic in future translations and to identify culturally specific phrasing. RESULTS: No PRO measures appropriate to address hypoparathyroidism symptoms documented in the literature were identified. Qualitative research participants included 11 women and one man, with an average age of 49 years; the majority (10) of these participants were white. Concept elicitation interview results were generally consistent with the results of the literature review; the most commonly reported symptoms included issues with cognition, often described as "brain fog" (n = 6), muscle cramping (n = 5), tingling (n = 5), and muscle spasms or twitching (n = 4). The initial draft item pool included 20 items; based upon participant feedback, the final Hypoparathyroidism Symptom Diary comprised 13 items and was found to be easily understood and relevant to the participants. No significant issues were identified by the translatability assessment. CONCLUSION: The Hypoparathyroidism Symptom Diary was developed following the recommendations of the FDA's PRO guidance. The measure addresses a comprehensive set of symptoms, as well as key impacts of hypoparathyroidism deemed important by patients. FUNDING: Shire Human Genetic Therapies, Inc., Lexington, MA, USA, a member of the Takeda group of companies.

Clinical burden and healthcare resource utilization among patients with chronic hypoparathyroidism, overall and by adequately vs not adequately controlled disease: a multi-country chart review.

Aims: To assess the real-world clinical burden and healthcare resource utilization (HRU) among patients with chronic hypoparathyroidism, overall and by adequately controlled (AC) vs not adequately controlled (NAC) disease, informed by guideline-recommended clinical management targets, including biochemistry and symptoms. Materials and methods: In this retrospective online chart review, endocrinologists in the US, Canada, the UK, France, Germany, Italy, and Spain were randomly selected to review the medical charts of adult patients with chronic hypoparathyroidism receiving calcium and activated vitamin D. Patients' demographics, disease characteristics, symptoms, comorbidities, and hypoparathyroidism-related HRU during the 1 year before the review date were assessed. Clinical burden and HRU were compared between patients with NAC and AC hypoparathyroidism. Results: Of 614 patients with hypoparathyroidism (AC, N = 442; NAC, N = 172), the mean age was 43.6 years, and the majority were female (61.6%), Caucasian (78.8%), and had post-surgical hypoparathyroidism (74.4%). Mean duration of hypoparathyroidism was 46.0 months. Hypoparathyroidism-related symptoms and comorbidities were reported in 59.4% and 46.7% of patients, respectively; 90.7% of patients had ≥1 hypoparathyroidism-related HRU event. More patients with NAC (57.6%) vs AC (42.5%) hypoparathyroidism experienced ≥1 comorbidity including calcium/phosphate imbalances, and brain, cardiovascular, metabolic, and renal disorders (all p < 0.01). More patients with NAC vs AC hypoparathyroidism incurred ≥1 hypoparathyroidism-related hospitalization (27.9% vs 16.3%) and emergency room visits (47.7% vs 38.5%), and patients with NAC vs AC hypoparathyroidism had a higher number of outpatient visits (3.6 vs 2.6; all p < 0.05), in the 1-year observation period. Limitations and conclusions: Limitations of this online chart review include possible under-estimation of disease burden, limited sample size, and the inability to rule out selection bias. Findings indicate that patients with chronic hypoparathyroidism experience substantial symptomatic and comorbid burdens resulting in frequent HRU, suggesting an unmet need, particularly in NAC disease.

Psychometric evaluation of the hypoparathyroidism symptom diary.

PURPOSE: To conduct an initial psychometric evaluation of the reliability and validity of the Hypoparathyroidism Symptom Diary (HPT-SD). PATIENTS AND METHODS: Data were collected during a cross-sectional, observational study. Participants with self-reported hypoparathyroidism (HPT) completed the HPT-SD, the Functional Assessment in Cancer Therapy-Cognitive Function (FACT-Cog), the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue), and the Hospital Anxiety and Depression Scale (HADS) measures. Item- and scale-level internal consistency reliability, known-groups validity, and construct validity were evaluated. Subscales were identified and preliminary scoring algorithms were developed. RESULTS: The study included 52 participants (mean age, 51 years). Overall, the measurement properties of the HPT-SD were very good. Item-level response frequency distributions showed evidence of possible floor effects for four muscle-related symptom items. Inter-item correlations revealed a pattern of relationships among symptom items (r=0.3-0.8) and among impact items (r=0.5-0.7) and provided evidence for two HPT-SD subscales: Symptoms and Impacts. Construct validity correlations supported a priori convergent validity hypotheses (|r|≥0.4) between HPT-SD subscales and the FACT-Cog, FACIT-Fatigue, and HADS. Mean HPT-SD Symptom and Impact scores were in the expected direction and significantly different between subgroups of patients with high and low HPT disease severity. CONCLUSION: Results indicate that the HPT-SD is an appropriate measure of HPT-related symptoms and impacts. Floor effects may be attributed to the observational study design: participants manage symptoms with calcium and active vitamin D supplements prior to an escalation in severity. Future studies should assess the HPT-SD measurement properties using longitudinal study designs.

Recombinant Human Parathyroid Hormone Effect on Health-Related Quality of Life in Adults With Chronic Hypoparathyroidism.

Context: Reduced health-related quality of life (HRQoL) is common in patients with hypoparathyroidism treated conventionally with calcium and active vitamin D supplements. Objective: To examine the effects of recombinant human parathyroid hormone [rhPTH(1-84)] on HRQoL as measured by the 36-Item Short-Form Health Survey (SF-36) during a multinational, randomized, placebo-controlled study. Patients: Adults (N = 122) with chronic hypoparathyroidism. Intervention(s): After an optimization period when calcium and/or active vitamin D supplements were adjusted to reach target serum calcium levels (8.0 to 9.0 mg/dL; 2.0 to 2.2 mmol/L), patients were randomly assigned to receive placebo (n = 39) or rhPTH(1-84) (n = 83) (starting dose, 50 µg/d, could be titrated up to 100 µg/d); supplement doses were adjusted to maintain target serum calcium levels. Main Outcome Measure(s): Change from baseline (postoptimization, at randomization) to week 24 in HRQoL as assessed by the SF-36. Results: Overall, the between-group differences were not statistically significant. However, in the rhPTH(1-84) group, there were significant improvements in the physical component summary score (P = 0.004), and in body pain (P < 0.05), general health (P < 0.05), and vitality (P < 0.001) domains as compared with baseline values. In the placebo group, there were no significant changes for any domains. The magnitude of change between 0 and 24 weeks in SF-36 scores was negatively correlated with baseline scores, such that patients with lower HRQoL at baseline were more likely to experience improvement in response to treatment. Conclusion: Treatment with rhPTH(1-84) may improve HRQoL in adults with hypoparathyroidism.

Safety and Efficacy of Recombinant Human Parathyroid Hormone in Adults With Hypoparathyroidism Randomly Assigned to Receive Fixed 25-µg or 50-µg Daily Doses.

PURPOSE: The present study examined the efficacy and safety of a lower rhPTH(1-84) dose. METHODS: RELAY was a dose-blinded, multicenter, 8-week study of patients with hypoparathyroidism randomized to fixed 25- or 50-µg/d doses of subcutaneous rhPTH(1-84). The primary end point was the percentage of patients at week 8 with supplement reductions in calcium to ≤500 mg/d and in calcitriol to ≤0.25 µg/d, while maintaining serum calcium levels between 1.875 mmol/L and the upper limit of normal. The secondary end point was the percentage of patients at week 8 with a ≥50% reduction in calcium and calcitriol doses, while maintaining serum calcium levels between 1.875 mmol/L and the upper limit of normal. FINDINGS: Forty-two patients were randomized (25-µg group, n = 19; 50-µg group, n = 23). At week 8, the primary end point was achieved by 4 (21%; 95% CI, 6%-46%) and 6 (26%; 95% CI, 10%-48%) of the patients receiving 25 and 50 µg/d of rhPTH(1-84), respectively. The secondary end point was achieved by 2 (11%; 95% CI, 1%-33%) and 6 (26%; 95% CI, 10%-48%) of the patients receiving 25 and 50 µg/d of rhPTH(1-84), respectively. Treatment-emergent adverse events were reported by 11 (58%) patients in the 25-µg group and 17 (74%) patients in the 50-µg group. IMPLICATIONS: Doses as low as 25 µg/d of rhPTH(1-84) are well tolerated and may be effective for a subset of patients. ClinicalTrials.gov identifier: NCT01268098.

Development of stable liquid glucagon formulations for use in artificial pancreas.

A promising approach to treat diabetes is the development of fully automated artificial/bionic pancreas systems that use both insulin and glucagon to maintain euglycemia. A physically and chemically stable liquid formulation of glucagon does not currently exist. Our goal is to develop a glucagon formulation that is stable as a clear and gel-free solution, free of fibrils and that has the requisite long-term shelf life for storage in the supply chain, short-term stability for at least 7 days at 37°C, and pump compatibility for use in a bihormonal pump. We report the development of two distinct families of stable liquid glucagon formulations which utilize surfactant or surfactant-like excipients (LMPC and DDM) to "immobilize" the glucagon in solution potentially through the formation of micelles and prevention of interaction between glucagon molecules. Data are presented that demonstrate long-term physical and chemical stability (~2 years) at 5°C, short-term stability (up to 1 month) under accelerated 37°C testing conditions, pump compatibility for up to 9 days, and adequate glucose responses in dogs and diabetic swine. These stable glucagon formulations show utility and promise for further development in artificial pancreas systems.

A review of a family of ultra-rapid-acting insulins: formulation development.

This review summarizes the clinical development of a family of ultra-rapid-acting recombinant human insulin formulations. These formulations use ethylenediaminetetraacetic acid (EDTA) to chelate zinc and thereby destabilize insulin hexamers. In addition, insulin monomer surface charges are chemically masked with citrate to prevent reaggregation. The first phase 1 trials were performed using BIOD-090, an acidic 25 unit U/ml insulin formulation, which contained disodium-EDTA (NaEDTA). When compared with regular human insulin (RHI) and/or insulin lispro in multiple phase 1 studies, BIOD-090 consistently showed more rapid absorption and/or onset of action. A standard meal challenge study also demonstrated improved postprandial glucose profiles associated with BIOD-090. However, increased patient exposure in larger phase 3 trials showed that this formulation was associated with an increased incidence of local injection site reactions, most commonly pain. A next generation formulation, BIOD-100, contained the same excipients as a standard insulin concentration of 100 U/ml. BIOD-100 maintained an ultra-rapid action profile and was associated with modest but significantly improved toleration when compared with BIOD-090. In order to further improve toleration, the hypothesis that NaEDTA contributed to discomfort by chelating endogenous calcium was tested by either substituting calcium-EDTA for NaEDTA or by adding calcium chloride to the NaEDTA formulation. These calcium formulations essentially eliminated the excess discomfort associated with BIOD-090 but were associated with less optimal pharmacokinetic profiles in humans. Recent efforts have succeeded in developing ultra-rapid-acting human insulin formulations with acceptable injection site toleration by optimizing concentrations of calcium (BIOD-125) and with the use of magnesium sulfate to mitigate discomfort (BIOD-123). Similar formulation technology has also been shown to accelerate absorption of insulin analogs in animal models.

Postprandial vascular effects of VIAject compared with insulin lispro and regular human insulin in patients with type 2 diabetes.

OBJECTIVE: Recent studies suggested an impact of prandial insulin delivery on postprandial regulation of tissue blood flow. This study compared the effect of VIAject with human regular insulin and insulin lispro on postprandial oxidative stress and endothelial function in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: Fourteen patients (seven men; aged 61.5 +/- 1.8 years; duration of diabetes 6.6 +/- 4.6 years; A1C 7.2 +/- 0.5% [mean +/- SEM]) received a prandial injection of VIAject, human regular insulin, and insulin lispro. At baseline and after a standardized liquid meal test (Ensure Plus), the postprandial increases in asymmetric dimethylarginine (ADMA) and nitrotyrosine levels were investigated. In addition, the postprandial effects on microvascular blood flow, skin oxygenation, and vascular elasticity were measured. RESULTS: Treatment with VIAject resulted in a significant reduction in the peak postprandial generation of ADMA compared with human insulin and insulin lispro (VIAject -27.3 +/- 22.6, human insulin 97.7 +/- 24.4, and insulin lispro 66.9 +/- 33.9 nmol/l; P < 0.05, respectively). The postprandial increases in nitrotyrosine levels were significantly less after VIAject than after human regular insulin (VIAject -0.22 +/- 0.17 vs. human insulin 0.25 +/- 0.15 microg/ml; P < 0.05), whereas nitrotyrosine after insulin lispro was in between (insulin lispro 0.09 +/- 0.07 microg/ml; NS). In parallel, earlier and more pronounced increases in microvascular blood flow and skin oxygenation were obtained after VIAject compared with those after human insulin or insulin lispro (P < 0.05, respectively). All insulin formulations resulted in comparable improvements in central arterial elasticity. CONCLUSIONS; Treatment with VIAject reduced postprandial oxidative stress and improved endothelial function compared with human regular insulin or insulin lispro.

Safety and efficacy of inhaled human insulin (Exubera) during discontinuation and readministration of therapy in adults with type 1 diabetes: A 3-year randomized controlled trial.

OBJECTIVE: To assess pulmonary safety during discontinuation and readministration of inhaled human insulin (EXU; Exubera((R)) insulin human [rDNA origin]) Inhalation Powder) therapy in adults with type 1 diabetes. METHODS: Patients were randomized to receive basal insulin plus either pre-meal EXU (n=290) or a short-acting subcutaneous (SC) insulin (n=290) for 2 years (comparative phase), followed by 6 months of SC insulin (washout) and 6 months of their original therapy (readministration). Highly standardized lung function tests were performed throughout. RESULTS: Small treatment group differences favoring SC insulin in change from baseline forced expiratory volume in 1s (FEV(1)) and carbon monoxide diffusing capacity (DL(CO)) occurred early and were non-progressive. These differences resolved during washout and recurred at the same magnitude during readministration. Both groups maintained glycemic control, and hypoglycemic event rates were similar. In the EXU group, insulin antibody (IAb) levels plateaued at 12 months, declined to near baseline levels during washout and increased during readministration to levels observed in the comparative phase. CONCLUSIONS: FEV(1) and DL(CO) changes observed during discontinuation and readministration of EXU therapy are consistent with a reversible, non-progressive and non-pathological effect on lung function. EXU readministration is not associated with an augmented IAb response.

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.

Immunological responses to exogenous insulin.

Regardless of purity and origin, therapeutic insulins continue to be immunogenic in humans. However, severe immunological complications occur rarely, and less severe events affect a small minority of patients. Insulin autoantibodies (IAAs) may be detectable in insulin-naive individuals who have a high likelihood of developing type 1 diabetes or in patients who have had viral disorders, have been treated with various drugs, or have autoimmune disorders or paraneoplastic syndromes. This suggests that under certain circumstances, immune tolerance to insulin can be overcome. Factors that can lead to more or less susceptibility to humoral responses to exogenous insulin include the recipient's immune response genes, age, the presence of sufficient circulating autologous insulin, and the site of insulin delivery. Little proof exists, however, that the development of insulin antibodies (IAs) to exogenous insulin therapy affects integrated glucose control, insulin dose requirements, and incidence of hypoglycemia, or contributes to beta-cell failure or to long-term complications of diabetes. Studies in which pregnant women with diabetes were monitored for glycemic control argue against a connection between IAs and fetal risk. Although studies have shown increased levels of immune complexes in patients with diabetic microangiopathic complications, these immune complexes often do not contain insulin or IAs, and insulin administration does not contribute to their formation. The majority of studies have shown no relationship between IAs and diabetic angiopathic complications, including nephropathy, retinopathy, and neuropathy. With the advent of novel insulin formulations and delivery systems, such as insulin pumps and inhaled insulin, examination of these issues is increasingly relevant.

Insulin antibodies with pulmonary delivery of insulin.

BACKGROUND AND METHODS: Delivery of insulin to the deep lung presents unique challenges to the body's mucosal defense system. Pulmonary mucosal defense has the ability to discriminate between self and non-self antigens and has the potential for induction of immunologic tolerance. Published data concerning the immunogenicity of inhaled human insulin in drug trials will be reviewed, and data regarding the possible adverse effects of anti-insulin antibody development will be presented. Examination of the immunologic safety of inhaled human insulin will include discussion of comparator studies, factors affecting immunogenicity, the effects of insulin immunity on glycemic control and pulmonary function, and the relationship of insulin antibodies to dose requirements, pharmacodynamics, and hypoglycemia. CONCLUSIONS: Inhaled human insulin, whether formulated as a powder or liquid, has been shown to be more immunogenic than comparator insulins given by subcutaneous routes; however, adverse effects of antibody formation have not been demonstrated.

The effect of insulin antibodies on the metabolic action of inhaled and subcutaneous insulin: a prospective randomized pharmacodynamic study.

OBJECTIVE: To assess the impact of the development of high- or low-affinity insulin antibodies (IABs) on postprandial glucose tolerance, duration of insulin action, and clinical safety in patients with type 1 diabetes receiving inhaled insulin (Exubera). RESEARCH DESIGN AND METHODS: This study consisted of a prospective, randomized, open-label, parallel-group trial in which 47 patients with type 1 diabetes received NPH insulin twice daily plus either premeal inhaled insulin (INH group; n = 24) or pre-meal subcutaneous regular insulin (SC group; n = 23) for 24 weeks. Meal challenge and euglycemic clamp studies were performed on consecutive days at baseline, week 12, and week 24. Adverse events were monitored. RESULTS: For the INH and SC groups, mean (+/-SD) IAB levels were 3.5 +/- 3.9 and 2.6 +/- 4.1 muU/ml at baseline, respectively, compared with 101.4 +/- 140.4 and 4.3 +/- 9.4 microU/ml at week 24. At week 24, the changes from baseline were similar for the INH and SC groups for maximal plasma glucose concentration (C(max)) (adjusted ratio for treatment group difference 0.99 [90% CI 0.95-1.03]), area under the plasma glucose concentration time curve (adjusted ratio for treatment group difference 0.98 [0.88-1.08]), and duration of insulin action (adjusted treatment group difference 29 min [-49 to 108]). No adverse events were attributed to IABs. CONCLUSIONS: In patients with type 1 diabetes treated with inhaled insulin, development of high- or low-affinity IABs did not impair postprandial glucose tolerance, alter the time-action profile of insulin, or impact tolerability. No clinical relevance of IABs was identified in this study.

Antibody response to inhaled insulin in patients with type 1 or type 2 diabetes. An analysis of initial phase II and III inhaled insulin (Exubera) trials and a two-year extension trial.

OBJECTIVE: To compare antibody responses to inhaled human insulin vs. sc human insulin and to determine whether insulin antibody binding is associated with adverse clinical consequences. RESEARCH DESIGN AND METHODS: Insulin antibody data from initial phase II/III trials were analyzed comparing the efficacy and safety of inhaled insulin with various agents, including sc insulin. Additionally, data from a 24-month extension of the phase III studies were examined. Data were pooled into the following three groups based on insulin treatment status at baseline: patients with type 1 diabetes, and patients with type 2 diabetes using insulin and not using insulin at baseline. Ig class analysis was also performed on randomly selected sera from type 1 patients at the end of the initial trials. RESULTS: In the initial trials, greater insulin antibody binding was observed in patients receiving inhaled insulin vs. sc insulin. The greatest antibody responses to inhaled insulin were observed in patients with type 1 diabetes [nonparametric comparison of medians at the end of the study, 22.0% binding (unadjusted 95% confidence interval: 19.5, 24.5)], and the lowest responses were observed in non-insulin-using patients with type 2 diabetes in which there was no difference in median values at the end of the study. There were no correlations between antibody binding and glycemic control (measured using glycosylated hemoglobin), insulin dose requirements, hypoglycemic events, or pulmonary function (measured by changes in forced expiratory volume in 1 sec and diffusion capacity of carbon monoxide). Antibody responses were IgG in type. Differences in antibody levels observed in patients with type 1 vs. type 2 diabetes were maintained over the 24-month extension trials. Peak antibody levels across all groups were generally observed after 6-12 months of insulin therapy. Inhaled insulin therapy was not associated with a greater incidence of allergy or other hypersensitivity reactions. CONCLUSION: Inhaled insulin was observed to produce a larger antibody response than sc insulin. Insulin antibody binding has not been associated with adverse clinical consequences in trials to date.