Diabetes, Thyroid & Metabolic Bone
A comprehensive analysis of the endocrinology clinical trial landscape — from continuous glucose monitoring integration and HbA1c-guided patient stratification to GLP-1 pipeline expansion, islet cell replacement therapies, and development dynamics across type 1 and type 2 diabetes, thyroid disorders, and metabolic bone disease.
The Endocrinology Trial Landscape in 2026
Endocrinology — and diabetes in particular — represents one of the most dynamic therapeutic areas in clinical development. The global diabetes epidemic, now affecting over 540 million adults worldwide, has created an enormous and expanding addressable patient population that drives both commercial opportunity and clinical trial volume. Within the Clinitiative network, endocrinology comprises 22 active studies spanning type 2 diabetes (T2D), type 1 diabetes (T1D), thyroid disorders, growth hormone deficiency, adrenal conditions, and osteoporosis. T2D studies dominate the portfolio with 14 active protocols, reflecting the extraordinary pipeline expansion driven by GLP-1 receptor agonist success and the emergence of multi-agonist therapies targeting obesity-related metabolic dysfunction.
The distribution of endocrinology studies across our network reflects current pipeline priorities. T2D studies span oral and injectable GLP-1 receptor agonists, dual GIP/GLP-1 agonists, triple agonists (GIP/GLP-1/glucagon), next-generation insulin formulations, and SGLT2 inhibitor combinations. T1D studies account for 4 active protocols focused on disease-modifying immunotherapy (teplizumab-class agents), closed-loop insulin delivery systems, and islet cell transplantation. Thyroid disorders contribute 2 studies targeting differentiated thyroid cancer and autoimmune thyroiditis, while osteoporosis and metabolic bone disease account for 2 studies evaluating novel bone-forming agents and sequential therapy strategies. Growth hormone and adrenal conditions are represented by 1 study each, with long-acting growth hormone formulations and adrenal insufficiency replacement optimization protocols.
The integration of continuous glucose monitoring (CGM) technology has fundamentally transformed diabetes trial design and endpoint measurement. Time-in-range (TIR) — the percentage of time glucose values remain within the 70-180 mg/dL target range — has emerged as a consensus endpoint endorsed by regulatory agencies and clinical guideline bodies, supplementing or in some studies replacing traditional HbA1c-based primary endpoints. This shift creates new infrastructure requirements for CGM device provisioning, data platform integration, and real-time glycemic data quality management that distinguish endocrinology sites from those in other therapeutic areas.
Key Performance Metrics
Network-wide benchmarks from our endocrinology portfolio provide critical reference points for study planning and site performance evaluation across diabetes, thyroid, and metabolic bone indications.
Across all endocrinology indications, our network sites achieve a median enrollment rate of 3.2 patients per site per month, the highest of any therapeutic area in our portfolio. T2D studies lead at 3.8 patients per site per month, driven by the vast prevalence of type 2 diabetes and established primary care and endocrinology referral networks. T1D studies average 1.9 patients per site per month, reflecting the smaller but highly engaged patient population. Osteoporosis and thyroid studies fall between these benchmarks at 2.4 and 2.1 patients per site per month respectively.
Screen failure rates across the endocrinology portfolio average 26%, with HbA1c range requirements serving as the primary driver. T2D studies typically require HbA1c values within narrow windows (e.g., 7.5-10.5%) that exclude patients with well-controlled or severely uncontrolled diabetes. Run-in period failures account for an additional 15% attrition, as patients may not tolerate background medication changes, fail to demonstrate compliance with CGM wear, or experience glycemic excursions during dose stabilization phases that disqualify them from randomization.
From contract execution to first patient enrolled, endocrinology sites within the network achieve a median startup time of 10.4 weeks, the fastest across our therapeutic portfolio. This efficiency reflects well-established regulatory pathways for diabetes and endocrine studies, standardized laboratory requirements that do not demand specialty testing infrastructure, and the broad availability of endocrinology investigators with clinical trial experience. Sites with pre-existing CGM data management platforms achieve startup 2-3 weeks faster than sites requiring de novo CGM infrastructure deployment.
The overall patient retention rate across endocrinology studies is 82%, moderate compared to other chronic disease areas. Long study durations (cardiovascular outcome trials in diabetes may extend 4-6 years), lifestyle modification requirements, and the burden of frequent glucose monitoring contribute to attrition. T1D studies show slightly higher retention at 87%, reflecting the highly engaged patient population and the appeal of novel therapies for a condition with significant daily management burden. Retention strategies including flexible visit scheduling, telehealth options, and CGM-based remote monitoring have improved retention by 8-12% at sites implementing comprehensive engagement programs.
Network Capabilities
Executing endocrinology trials at the pace and data quality required by modern CGM-integrated, outcome-driven protocols demands specialized infrastructure, digital health expertise, and deep understanding of metabolic disease management. Our network has been strategically developed to ensure comprehensive endocrinology-specific capabilities at every participating site.
Continuous Glucose Monitoring Infrastructure
CGM has become the foundational technology for modern diabetes trial endpoint assessment. Our network sites maintain comprehensive CGM infrastructure including device inventory management for multiple CGM platforms (Dexcom, Abbott Libre, Medtronic), trained staff for sensor placement and troubleshooting, data upload stations with validated software for CGM data download, and established workflows for CGM data quality review including minimum wear-time verification, calibration compliance, and signal gap analysis.
For blinded CGM studies — where patients wear sensors for data collection but do not see real-time glucose values — sites maintain device configuration protocols that ensure blinding integrity while maximizing data capture. Integration with sponsor-specified cloud data platforms enables near-real-time CGM data transmission for centralized monitoring and interim analysis support. Sites with mature CGM programs achieve greater than 90% CGM data completeness rates, compared to an industry average of 78%.
Endocrine Function Testing
Endocrinology protocols frequently require specialized provocation and suppression testing that goes well beyond routine laboratory assessments. Our network sites maintain capabilities for oral glucose tolerance testing (OGTT) with timed insulin and C-peptide sampling for beta cell function assessment, hyperinsulinemic-euglycemic clamp studies for insulin sensitivity quantification, mixed-meal tolerance testing for incretin response evaluation, and stimulation tests including ACTH stimulation for adrenal function, GnRH stimulation for gonadal axis assessment, and growth hormone stimulation testing.
These procedures require dedicated procedure rooms with infusion pump capabilities, timed blood sampling protocols with precise collection windows, trained nursing staff experienced in endocrine testing procedures, and immediate access to glucose for hypoglycemia management during insulin- based testing. Sites with established endocrine testing programs achieve 95% protocol-compliant sample collection compared to 82% at sites implementing these procedures for the first time.
Diabetes Education & Support Programs
Effective diabetes trial execution requires patient education infrastructure that supports protocol compliance, glucose monitoring adherence, and lifestyle modification components that are integral to many study designs. Our network sites employ certified diabetes care and education specialists (CDCES) who provide study-specific patient education including CGM training, insulin injection technique, carbohydrate counting, hypoglycemia recognition and management, and sick-day management protocols.
Registered dietitian nutritionists with diabetes expertise support studies requiring dietary standardization or lifestyle intervention components. This education infrastructure directly impacts study outcomes — sites with integrated diabetes education programs demonstrate 22% lower rates of protocol deviations related to glucose monitoring non-compliance, missed insulin dose documentation, and dietary protocol violations compared to sites without dedicated education support.
DXA & Bone Health Assessment
Metabolic bone disease studies and osteoporosis trials require dual-energy X-ray absorptiometry (DXA) scanning capabilities with standardized acquisition protocols, longitudinal quality assurance procedures, and trained technologists who ensure reproducible positioning and analysis. Our network sites maintain research-qualified DXA scanners with cross-calibration capabilities for multi-site studies, enabling consistent bone mineral density (BMD) measurements at the lumbar spine, femoral neck, and total hip across geographically distributed sites.
Fracture risk assessment tools including FRAX scoring, trabecular bone score (TBS) analysis, and vertebral fracture assessment (VFA) by DXA are available for studies requiring comprehensive bone health characterization. Sites also support bone turnover marker collection and processing (CTX, P1NP, osteocalcin) with appropriate fasting and timing protocols that ensure analytical validity.
Enrollment Dynamics
Endocrinology enrollment benefits from enormous patient populations, particularly in type 2 diabetes, but this abundance creates its own challenges including intense sponsor competition for the same patient pools and narrow eligibility windows defined by glycemic control parameters. Understanding these dynamics is essential for realistic enrollment planning and site performance optimization.
The commercial success of GLP-1 receptor agonists for both diabetes and obesity has created an unprecedented challenge for clinical trial enrollment. Patients who might previously have been eligible for investigational GLP-1 studies are now receiving commercially available agents, reducing the pool of GLP-1-naive patients available for clinical trials. Studies requiring GLP-1-naive populations have seen enrollment rates decline by approximately 25% over the past two years as commercial penetration has expanded. Conversely, studies evaluating next-generation agents in GLP-1-experienced populations or combination strategies benefit from the growing pool of patients with established GLP-1 exposure.
HbA1c eligibility windows create timing challenges unique to diabetes enrollment. Most T2D studies require HbA1c values within specific ranges — typically 7.5% to 10.5% — that exclude patients at both ends of the glycemic control spectrum. Because HbA1c reflects average glycemia over 2-3 months, a patient whose HbA1c falls outside the eligibility window at screening must wait months before rescreening, during which time they may enroll in a competing study or initiate treatment changes that further alter their eligibility. Our network addresses this through rolling HbA1c pre-screening programs that maintain databases of patients with recent HbA1c values, enabling targeted outreach when values fall within study-specific ranges.
Background medication washout and run-in period attrition represent significant enrollment bottlenecks. Many diabetes studies require washout of specific background therapies (e.g., sulfonylureas, DPP-4 inhibitors) or include run-in periods during which patients must demonstrate compliance with study procedures, tolerate background therapy adjustments, or achieve stable glycemic baselines before randomization. Run-in attrition rates of 12-18% are common in diabetes studies, effectively reducing the number of screened patients who reach randomization and requiring over-screening strategies that must be factored into enrollment planning and site budgets.
Key Challenges in Endocrinology Trial Execution
The evolving regulatory landscape, technological integration demands, and competitive enrollment environment create operational challenges that require specialized strategies and deep endocrinology expertise.
Background Therapy Management
Diabetes patients typically present on complex multi-drug regimens that must be carefully managed within the context of clinical trial protocols. Metformin requirements are nearly universal in T2D studies as mandated background therapy, requiring dose optimization and tolerability confirmation during screening or run-in. Insulin dose adjustment protocols must balance glycemic safety with the need for stable baseline measurements. The addition or withdrawal of background therapies during the study period requires predefined rescue therapy algorithms that protect patient safety while minimizing impact on efficacy endpoints. Our sites maintain clinical pharmacist support for protocol-specific medication management and coordinate with treating endocrinologists to ensure background therapy decisions align with both study requirements and individual patient needs.
HbA1c Eligibility Windows
The narrow HbA1c ranges required for most diabetes studies create a persistent enrollment challenge that is further complicated by seasonal variation in glycemic control. Network data shows HbA1c values trend 0.2-0.4% higher during winter months due to reduced physical activity, dietary changes, and illness-related glycemic excursions. This seasonal pattern means that patients who are eligible during one screening period may fall outside eligibility windows in subsequent months, creating unpredictable enrollment velocity fluctuations. Our sites mitigate this through year-round HbA1c surveillance programs, pre-screening databases that flag patients approaching eligibility thresholds, and proactive patient engagement strategies that maintain contact with near-eligible patients for rescreening at optimal timepoints.
Cardiovascular Outcome Requirements
FDA guidance requiring cardiovascular outcome trials (CVOTs) for new diabetes therapies has fundamentally shaped the T2D development landscape. CVOTs mandate large sample sizes (typically 7,000-15,000 patients), extended follow-up periods (median 3-5 years), and adjudicated MACE endpoints that require infrastructure for long-term patient retention, event identification and documentation, and coordination with central adjudication committees. While recent regulatory discussions have explored more flexible approaches to cardiovascular safety assessment, the CVOT framework continues to influence study design, site selection, and enrollment planning for the majority of late-phase T2D programs in our network.
CGM & Digital Integration
The adoption of CGM as a primary or key secondary endpoint creates operational challenges around data standardization, device compatibility, and data quality management. Different CGM platforms use distinct algorithms, calibration requirements, and accuracy profiles, creating potential variability in time-in-range calculations across devices. Sponsor-specified CGM platforms may differ from patients' personal CGM devices, requiring dual-wear periods and patient education on study-specific device management. Data transmission failures, sensor malfunctions, and minimum wear-time compliance monitoring generate significant coordinator workload. Our network has developed standardized CGM management protocols including device inventory tracking, patient training curricula, data completeness dashboards, and escalation procedures for technical issues that maintain data quality across large multi-site diabetes studies.
Pipeline Analysis
The endocrinology development pipeline is experiencing unprecedented expansion, driven by the transformative success of incretin-based therapies, renewed interest in disease-modifying approaches for type 1 diabetes, and emerging precision medicine strategies in thyroid and endocrine oncology. Several therapeutic modalities are driving significant evolution in trial design, site requirements, and enrollment planning.
Next-Generation GLP-1 & Multi-Agonist Therapies
The incretin therapy pipeline has evolved beyond single GLP-1 receptor agonism into multi-target combinations that simultaneously engage GLP-1, GIP, and glucagon receptors. Dual GIP/GLP-1 agonists have demonstrated superior glycemic and weight loss efficacy compared to selective GLP-1 agonists, while triple agonists (GIP/GLP-1/glucagon) represent the next frontier targeting metabolic dysfunction from multiple complementary pathways. Oral GLP-1 formulations in advanced development aim to eliminate injection barriers and expand the addressable patient population. These next-generation agents create trial design complexity around dose-finding in multi-target pharmacology, gastrointestinal tolerability assessment, and the need for head-to-head comparisons against increasingly effective active comparators rather than placebo.
Islet Cell & Beta Cell Therapies
The development of stem cell-derived islet cell therapies represents a potential paradigm shift in type 1 diabetes treatment, offering the possibility of insulin independence through cellular replacement rather than exogenous insulin administration. Programs utilizing human embryonic stem cell (hESC)-derived and induced pluripotent stem cell (iPSC)-derived beta cells are advancing through early-phase clinical trials, with encapsulated cell therapy approaches designed to protect transplanted cells from immune destruction without requiring systemic immunosuppression. These studies require specialized infrastructure including cell therapy administration capabilities, immunosuppressive regimen management, metabolic clamp testing for graft function assessment, and close monitoring for immune-mediated graft rejection. Sites participating in islet cell therapy programs must maintain relationships with transplant medicine services and have experience managing immunosuppressive protocols in non- transplant research populations.
Novel Insulin Technologies
Insulin therapy innovation continues to evolve toward formulations that more closely mimic physiological insulin secretion. Glucose-responsive "smart" insulins that modulate their activity based on ambient glucose concentrations represent the most transformative concept in the pipeline, offering the potential to dramatically reduce hypoglycemia risk while maintaining glycemic control. Ultra-long-acting basal insulin formulations with once-weekly dosing are in late-stage development, aiming to reduce injection burden and improve adherence in patients requiring basal insulin. Hepato- preferential insulin analogs that direct insulin action primarily to the liver rather than peripheral tissues may reduce weight gain and hypoglycemia associated with conventional insulin therapy. These novel insulin studies require intensive glycemic monitoring including CGM, frequent PK/PD sampling, and specialized hypoglycemia assessment protocols with standardized documentation of confirmed, severe, and nocturnal hypoglycemic events.
Thyroid & Endocrine Precision Medicine
Precision medicine approaches are reshaping therapeutic development in thyroid cancer and broader endocrine conditions. Targeted therapies for differentiated thyroid cancer driven by RET, NTRK, and BRAF mutation status have established the biomarker-selected treatment paradigm in thyroid oncology, with next-generation selective inhibitors offering improved specificity and reduced off-target toxicity. Personalized hormone replacement strategies leveraging pharmacogenomic testing to optimize levothyroxine, hydrocortisone, and growth hormone dosing represent an emerging approach to individualized endocrine care. Autoimmune thyroid disease programs investigating immunomodulatory therapies aim to address the underlying immune dysfunction rather than solely replacing hormone deficiency. These precision endocrinology studies require molecular diagnostic capabilities, pharmacogenomic testing infrastructure, and longitudinal hormone level monitoring with sufficient granularity to detect clinically meaningful changes in response to individualized dosing strategies.
Site Requirements for Endocrinology Excellence
The infrastructure, staffing, and operational processes required to execute modern endocrinology protocols at the highest level of quality and data integrity.
Multi-platform CGM device inventory and provisioning infrastructure, trained staff for sensor placement and patient education, validated data upload stations and cloud platform integration, data completeness monitoring dashboards, and established workflows for blinded CGM configuration, minimum wear-time verification, and technical troubleshooting.
Dedicated procedure rooms for OGTT, hyperinsulinemic- euglycemic clamp studies, mixed-meal tolerance testing, and hormonal stimulation tests. Infusion pump capabilities, timed blood sampling infrastructure, trained nursing staff experienced in endocrine provocation testing, and immediate hypoglycemia management resources.
Rapid-turnaround HbA1c, fasting glucose, fasting lipid panel, comprehensive metabolic panel, thyroid function tests (TSH, free T4, free T3), and specialized hormone assays (cortisol, ACTH, IGF-1, insulin, C-peptide). Specimen processing and shipping for central laboratory PK/PD and biomarker samples with appropriate cold-chain management.
Certified diabetes care and education specialists (CDCES) for CGM training, injection technique instruction, carbohydrate counting education, and hypoglycemia management training. Registered dietitian nutritionists for dietary protocol compliance support. Multilingual patient education materials and culturally appropriate counseling capabilities.
Dedicated research pharmacy with temperature-controlled storage for biologic agents (GLP-1 agonists, insulin analogs, monoclonal antibodies), automated drug accountability systems, and pharmacist oversight for complex background therapy management. Self-injection training infrastructure and device dispensing capabilities for pen and auto-injector delivery systems.
Dedicated endocrinology clinical research coordinators with experience in diabetes management, CGM technology, and metabolic testing procedures. Research nurses certified in insulin administration, infusion therapy, and hypoglycemia emergency management. Data managers with EDC proficiency and experience in CGM data integration and glycemic endpoint documentation.
Discuss Your Endocrinology Program
Connect with our team to explore site capabilities, enrollment strategies, and CGM infrastructure for your endocrinology clinical development program.