{'fraction_non_alphanumeric': 0.03808280289429302, 'fraction_numerical': 0.030955878352646755, 'mean_word_length': 4.7969094922737305, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 1, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Single‐dose euglycaemic clamp studies demonstrating pharmacokinetic and pharmacodynamic similarity between MK‐1293 insulin glargine and originator insulin glargine (Lantus) in subjects with type 1 diabetes and healthy subjects

Aims MK‐1293 is an insulin glargine that has an amino acid sequence identical to that of Lantus, the originator insulin glargine. Two euglycaemic clamp studies, 1 in subjects with type 1 diabetes (T1D) and 1 in healthy subjects, were conducted to demonstrate pharmacokinetic (PK) and pharmacodynamic (PD) similarity between MK‐1293 and Lantus commercially procured in both the European Union (EU‐Lantus) and the USA (US‐Lantus). Materials and Methods Both studies were single‐dose, randomized, double‐blind, single‐centre, crossover studies with ≥7 days between dosing periods. A 2‐treatment, 4‐period replicate crossover study in T1D subjects (N = 76) compared the PK and PD of MK‐1293 to EU‐Lantus for 30 hours after dosing. A 3‐period crossover study in healthy subjects (N = 109) compared the PK and PD of MK‐1293, EU‐Lantus and US‐Lantus for 24 hours after dosing. In both studies, all subjects received single 0.4 units/kg subcutaneous doses of MK‐1293 or Lantus in all dosing periods. Pharmacokinetic assessment was based on LC‐MS/MS‐based measurement of the major insulin glargine metabolite (M1) and PD was characterized using the euglycaemic clamp platform. Results In both studies, pre‐specified similarity criteria were met between MK‐1293 and Lantus for comparison of PK (AUC0‐24 and Cmax of M1) and PD (GIR‐AUC0‐24, GIR‐AUC0‐12, GIR‐AUC12‐24, and GIRmax) primary endpoints. All treatments were well tolerated. Conclusion Based on comparative assessment in both T1D and healthy subjects, it can be concluded that the PK and PD properties of MK‐1293 are highly similar to those of Lantus. (ClinicalTrials.gov: NCT02059174).


| INTRODUCTION
Insulin glargine is a recombinant human basal insulin analog produced in Escherichia coli (E. coli) that is marketed worldwide by Sanofi (Paris, France) under the trade name Lantus. Lantus is approved for the treatment of type 1 diabetes (T1D) and type 2 diabetes (T2D). 1,2 Though Lantus and other approved basal insulin products are effective treatments for patients with T1D and T2D, the cost of these products can present a barrier to patient access. High-quality follow-on basal insulin products, approved for marketing based on rigourous demonstration of similarity to approved reference products, are important treatment options that could increase access for a broader population of patients. The specific terminology applied to follow-on insulin products such as MK-1293 differs among regulatory regions.
They are designated as biosimilars in several regions including the European Union. 3 In the USA, while follow-on insulin products are not currently designated as biosimilars and are developed under a different regulatory pathway, 4 the same principle of establishing similarity to an approved reference product is applied.
Demonstration of similarity between follow-on and approved reference insulin products is based on a combination of analytical, preclinical and clinical data. Clinical similarity is assessed through Phase I comparisons of pharmacokinetic (PK) and pharmacodynamic (PD) properties as well as efficacy and safety comparisons in the Phase III setting. Because of the high sensitivity of PK and PD comparisons for discriminating potentially relevant differences between insulins, Phase I euglycaemic clamp studies play a central role in the assessment of clinical similarity. 3 MK-1293 is a follow-on insulin glargine that has the same amino acid sequence as Lantus and, like Lantus, is produced in E. coli. Similarity with regard to clinical efficacy and safety have been demonstrated between MK-1293 and Lantus in Phase III studies of subjects with both T1D 5 and T2D. 6 These studies demonstrated equivalent HbA1c reductions from baseline between MK-1293 and Lantus at highly similar doses, as well as similarity with regard to hypoglycaemia, body weight, general safety and immunogenicity.
The present paper reports on 2 euglycaemic clamp studies conducted to compare the clinical PK and PD properties of MK-1293 and Lantus. Because of differing cross-regional regulatory requirements, Study A compared MK-1293 and Lantus commercially procured in the EU (EU-Lantus) in T1D subjects, while Study B was conducted in healthy subjects and compared MK-1293, EU-Lantus and Lantus commercially procured in the USA (US-Lantus). Study B (PN002) was a double-blind, randomized, single-centre, 3-period complete crossover study in healthy subjects ( Figure S1B).

| Study design
In each period, eligible subjects received 1 of 3 single-dose treat-

| Study subjects
In Study A, subjects were men and women aged 18 to 65 years with a clinical diagnosis of T1D for ≥12 months, C-peptide concentration

| Pharmacokinetic sampling
Plasma samples were collected for PK analysis in Study A at −3 minutes prior to dosing and 1, 4, 8, 10, 12, 16, 20, 24,  In Study A, the clamp target was 130 mg/dL which was maintained initially through weaning of the overnight insulin infusion and then through initiation and adjustment of a glucose infusion. In Study B, the clamp target was 80 mg/dL, which was maintained through glucose infusion rate (GIR) adjustment, as needed. For both studies, a recommended GIR was calculated at each blood glucose sampling time point by a model-based algorithm and refined by the clamp director if necessary. The glucose infusion was discontinued by 30 (Study A) or 24 (Study B) hours after dosing, or earlier if not needed to maintain the clamp target blood glucose concentration.

| Bioanalytical methods
In both studies, a validated liquid chromatographic-tandem mass spectrometric (LC-MS/MS) detection method, modified from a previously published assay, 7 was used to simultaneously determine concentrations of parent insulin glargine and its 2 bioactive metabolites, M1 and M2. The method was based on an automated 96-well format immunoaffinity purification of analytes of interest from human plasma. Parent glargine, M1, M2 and their corresponding stable isotope-labeled internal standards were chromatographed using reversed phase LC and were detected with tandem mass spectrometric detection using multiple reaction montoring (MRM). The analytical range of quantification was 100 to 10 000 pg/mL for all analytes using 0.5 mL of plasma. All validation and sample quantification runs met the pre-specified acceptance criteria, including incurred sample reproducibility (ISR).

| Pharmacokinetic assessments
As M1 is the major circulating active glargine species after s.c. administration, [7][8][9] it was the primary PK analyte. Pharmacokinetic parameters included AUC 0-24 and C max (primary endpoints), as well as AUC 0-12 , AUC 12-24 and T max . The values of all individual PK parameters were calculated using noncompartmental methods in Phoenix Win-Nonlin v6.3 (Certara, St. Louis, Missouri). Areas under the curves (AUCs) were calculated using the linear trapezoidal method for ascending concentrations and the log trapezoidal method for descending concentrations (linear-up/log-down). A uniform weighting scheme was used. C max and T max were assessed directly from the observed concentration-time data taken directly from the bioanalytical data.
Consistent with regulatory guidance, 10 values of M1 below the lower limit of quantitation (LLOQ) were imputed as zero. Plasma concentrations for parent glargine and the M2 glargine metabolite were below the LLOQ for the majority of samples at all PK sampling time points.
Therefore, no PK parameters were calculated for these analytes.

| Pharmacodynamic assessments
GIR parameters in both studies included area under the GIR profile from 0 to 24 hours (GIR-AUC 0-24 ), GIR-AUC 0-12 , GIR-AUC 12-24 and maximum GIR value (GIR max ) (primary endpoints), as well as time to GIR max . GIR max is based on LOESS smoothed data where the AUC endpoints are based on observed data. The default smoothing function in SAS PROC LOESS, which selects an optimal smoothing parameter based on minimizing a bias-corrected AIC criterion, was used to fit an optimal smoothing function for each subject, treatment and period. In Study A, Duration of Action (DOA) was also a primary PD endpoint, defined as the length of time from dosing to end of action, the time point at which plasma glucose was >150 mg/dL for 30 minutes with no glucose infusion during that time. 11 There were 3 instances (of 290 total clamps) in which application of the end of action definition above clearly under-estimated the timing of end of action and the pre-specified definition of end of action was overruled. As end of action does not clearly manifest in healthy subjects, DOA was not assessed in Study B.

| Safety assessments
Adverse events (AEs) were assessed throughout the 2 studies. All clinical AEs were evaluated in terms of intensity, duration, severity, outcome and relationship to study medication. Other safety parameters, including vital signs, physical examinations, 12-lead electrocardiograms (ECGs), and standard laboratory safety tests, were assessed pre-dose and at various time points post-dose and post-study.

| Statistical analysis 2.10.1 | Pharmacokinetics
Individual M1 metabolite AUC 0-24 and C max values were natural logtransformed and analysed separately in linear mixed effects models appropriate for either a 2-treatment 4-period replicate crossover (Study A) or a 3-treatment 3-period crossover (Study B). A 90% CI for the difference in treatment means for pairwise treatment comparisons on the log scale was calculated using the mean square error from the model and referencing a t-distribution for each endpoint. The CIs were exponentiated to obtain the 90% CI for the geometric mean ratio for the treatment comparisons for AUC 0-24 and C max . Consistent with pertinent regulatory agency guidelines, 3,12-14 a conclusion of PK similarity for each study and treatment comparison would be supported if the 90% CIs for both AUC 0-24 and C max for a given treatment comparison were within the predefined similarity criteria of 0.80 and 1.25. The secondary endpoints of M1 AUC 0-12 and AUC [12][13][14][15][16][17][18][19][20][21][22][23][24] were analysed using the same statistical methods as described for M1 AUC 0-24 and C max .

| Pharmacodynamics
To assess glucose concentration variability around the clamp target, a Individual GIR parameter (GIR-AUC 0-24 , GIR-AUC 0-12 , GIR-AUC 12-24 and GIR max ) values were analysed with a linear mixed effects model with fixed effects terms for treatment and period. Fieller's Theorem 15 was used to calculate 95% (Study A) or 90% (Study B) CIs for the ratio of arithmetic means (test/reference) for each parameter and treatment comparison, using results from the linear mixed effects model and referencing a t-distribution. The use of 90% compared with 95% CIs was because of differing cross-regional regulatory agency requirements. In Study A, a conclusion of PD similarity between MK-1293 and EU-Lantus would be supported if the 95% CIs for the ratio of arithmetic means for all 4 primary GIR endpoints, as well as DOA, lay within the pre-specified boundaries. However, end of action did not occur within the 30-hour clamp timeframe in the majority of subjects for both treatments. Therefore, a DOA comparison based on a ratio of means could not be performed and a statistical comparison of DOA was conducted with a post-hoc survival analysis approach using hazard rates. A frailty model was used with effects for treatment, period and sequence, and a random effect for subject. From this model, the hazard ratio and Wald 95% CIs for treatment were obtained. A value of 1.00 for the hazard ratio corresponds to no difference between treatments. In Study B, a conclusion of PD similarity for each treatment comparison would be supported if the 90% CIs for the ratio of arithmetic means for all 4 primary GIR endpoints lay within (0.80, 1.25).

| Sample size
For both studies, an overall power of 80% to meet all study objectives was targeted. In the Study A protocol, assuming a 2-sided alpha of 0.025 for PD (95% CIs) and 0.05 for PK (90% CIs), and similarity bounds for the primary PK and PD endpoints as noted above, a sample size of 70 completers was predicted to provide at least 80% overall power. In the Study B protocol, assuming a 2-sided alpha of 0.05 (90% CIs) for all primary PK and PD endpoints and the similarity bounds noted above, a sample size of 72 completers was predicted to provide at least 80% overall power. Following the start of each study, an interim analysis for assessment of variance for the primary PK and PD endpoints was conducted to determine whether it was necessary to increase sample size to provide at least 80% overall power to meet all hypotheses. Mean treatment effects were not calculated during the interim analyses. These interim variance assessments were conducted by a pharmacokineticist and a statistician who were blinded to treatment and had no other involvement in these studies. For Study A, no increase in sample size was needed. For Study B, the interim analysis indicated that a sample size of 72 would not have provided at least 80% overall power; therefore, the sample size was increased from 72 to 96 completers.  Table 1. Of the 6 subjects who did not complete the study, 4 were withdrawn because of subject decision, 1 because of glucose infusion error, and 1 because of physician decision as the patient required antibiotic treatment.

| Pharmacokinetics
Mean PK profiles for the M1 glargine metabolite were similar between MK-1293 and EU-Lantus in subjects with T1D ( Figure 1A). The 90% CIs for the geometric mean ratios (MK-1293/Lantus) were within 0.80 and 1.25 for both primary PK endpoints (AUC 0-24 and C max ), thereby meeting the pre-specified statistical similarity criterion (Table 2). For both secondary PK endpoints of interest (AUC 0-12 and AUC 12-24 ), the 90% CIs for the geometric mean ratios (MK-1293/Lantus) were also within 0.80 and 1.25, although no statistical similarity criteria were pre-specified for these comparisons. Median M1 T max was approximately 12 hours for both treatments. The replicate design of Study A permitted assessment of within-subject, between-period PK variability.
The within-subject % CV for MK-1293 was consistent with that of EU-Lantus for all primary and secondary PK endpoints.

| Pharmacodynamics
During the timeframe of active glucose clamping (from initiation to completion of glucose infusion), mean plasma glucose concentration was very close to the clamp target of 80 mg/dL (80.6 mg/dL with a coefficient of variation of 4.7%). This is consistent with the reported clamping precision in similar studies and confirms that glucose clamping was achieved with a high degree of precision. 16,17 Mean GIR profiles were similar among all treatments ( Figure 1D). The 90% CIs for the arithmetic mean ratios (test/reference) for all 3 treatment comparisons were within 0.80 and 1.25 for all 4 primary GIR endpoints (GIR-AUC 0-24 , GIR-AUC 0-12 , GIR-AUC 12-24 , GIR max ), thereby meeting the pre-specified statistical similarity criterion (      and C max ) and secondary (M1 AUC 0-12 and AUC 12-24 ) PK endpoints were close to 1.0 (range: 0.92-1.02), and pre-specified similarity criteria (90% CIs of GMR between 0.80, 1.25) were met for both primary endpoints. Within-subject PK variability (% CV), assessed in Study A, was also similar between MK-1293 and Lantus.
The euglycaemic clamp platform is long established as the optimal approach for characterizing the PD profile of pharmacologic insulins and is recommended by the EMA for assessing pharmacologic similarity between insulin products. 3 Metrics characterizing accuracy and precision relative to clamp target glucose concentration confirmed high quality clamping in both studies. For both studies and all treatment comparisons, GIR profiles were closely aligned throughout the 24-to 30-hour assessment periods, arithmetic mean ratios for all primary GIR endpoints (GIR-AUC 0-24 , GIR-AUC 0-12 , GIR-AUC 12-24 , GIR max ) were close to 1.0 (range: 0.90-1.03), and pre-specified similarity criteria were met for each of these primary endpoints. Consistent with PK, MK-1293 within-subject PD variability (% CV), assessed in Study A, was also similar to that of Lantus. The duration of action of MK-1293, assessed in T1D subjects in Study A, was also similar to that of Lantus and was greater than 30 hours in the majority of subjects.
Over the first 12 hours after dosing in both studies, M1 exposure (AUC 0-12 ) and PD effect (GIR-AUC 0-12 ) were slightly lower for MK-1293 compared to Lantus. However, as these differences were small (mean treatment ratios ≥0.90) and protocol-specified similarity criteria were met for all comparisons, these observations do not alter the conclusion of PK and PD similarity between MK-1293 and Lantus. Phase III studies in T1D 5 and T2D 6 subjects demonstrating equivalent HbA1c reduction at highly similar doses indicate that any minor PK and PD differences that may exist between MK-1293 and Lantus are not clinically impactful.
Overall, these studies have demonstrated a high degree of PK and PD similarity between MK-1293 and Lantus in both T1D patients and healthy subjects. Given the strong relationship between insulin pharmacology and glycaemic efficacy, these data provide evidence that the clinical efficacy profile of MK-1293 is similar to that of Lantus, 3 an expectation that is confirmed by the results of Phase III studies in T1D 5 and T2D 6 subjects.
E. W., L. M. and M. H. conducted the studies, contributed to the discussion and reviewed/edited the manuscript. All of the authors are responsible for the work described in this manuscript. All authors were involved in at least 1 of the following: (1) conception, design, acquisition, analysis, statistical analysis or interpretation of data; (2) drafting the manuscript and/or revising it for important intellectual content. All authors provided final approval of the version to be published and agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.