Structuring Obesity Trials to Optimize Patient Retention and Data Integrity

Despite not finding a “one-size-fits-all” approach, new research has shown that obesity trials largely depend on phase-appropriate operational design to ensure positive outcomes, including intensive oversight and scalable support strategies.1

Presented at the American Diabetes Association (ADA) Scientific Sessions 2026 in New Orleans, Louisiana, by Shipra Patel, MD, MS, senior medical director, global head of pediatrics, and global section head of endocrinology and metabolism at Parexel, these data aim to provide clinicians with specific points to construct future trials around, prioritizing retention and the quality of endpoint data.1

“We’ve looked really closely at ways that we could promote retention, and a lot of it comes down to making sure they know exactly what they’re getting into,” Patel told HCPLive in an exclusive interview. “For example, they need to know that they’ll probably experience mild to moderate gastrointestinal adverse events if they are on a GLP-1 or a related compound. It really helps to have patient education early on for those trials, and they’re more likely to stick it out through the trial.”

Prior research has been conducted on this topic, with high attrition cited as the inciting incident. Many weight loss agents currently in the pipeline can lead to gastrointestinal adverse events, and another study has noted that roughly 1 in 3 patients drop out of large-scale, phase 3 trials of these agents by 1 year. This naturally results in missing data, limiting the generalizability of a given study’s findings.2

In an effort to counter this, Patel and colleagues conducted a review of 15 phase 1 and 2 obesity studies that took place between 2020 and 2025 in North America and Europe. These trials included first in human, dose escalation, and dose ranging studies, with structured post-study reviews and case study materials analyzed to find phase-specific best practices. The team emphasized site capabilities, patient experience, and retention in their search.1

Based on these trials, the team noted that phase 1 studies typically benefit from intensive oversight from investigators, as well as in-house patient stays and early-phase units assessment expertise and body composition imaging. Additionally, standardized imaging workflows and structured patient training tended to support integrity of data and timely decision-making.1

Phase 2 studies naturally required a focus on patient retention to ensure data integrity; to this end, Patel and colleagues found that participant compensation was the leading approach, despite not being consistently implemented. Transportation support and access to lifestyle counseling were also beneficial and were implemented in all 15 trials.1

Patel also provided advice for clinicians or investigators currently constructing phase 1 or 2 obesity trials, suggesting main areas of focus to ensure both patient retention and quality data collection.

“I think in terms of the phase 1 trials, it’s important to look closely at the eligibility criteria to see if the representative patient population will be included, and to make sure that they are being handled in the right facility,” Patel said. “For phase 2 trials, the critically important thing is to have flexibility in the dosing schedule – if a patient is on a GLP-1 and they experience GI effects, you might have to back down on the dosing a bit, and then go back up again.”

Editors’ Note: Patel reports no relevant disclosures.

References

1. Patel S, Eniu I. Patient-Centered Strategies to Optimize Phase I and II Obesity Trials. Abstract presented at the American Diabetes Association (ADA) Scientific Sessions 2026, New Orleans, LA. June 5-8, 2026.

2. Delahanty LM, Riggs M, Klioze SS, Chew RD, England RD, Digenio A. Maximizing retention in long-term clinical trials of a weight loss agent: use of a dietitian support team. Obes Sci Pract. 2016;2(3):256-265. doi:10.1002/osp4.57