What are Endpoints? How can endpoints make clinical trials more patient-friendly and lead to better drugs?

Introduction

Clinical trials are essential for discovering new treatments and medical procedures. A critical part of these trials is choosing and evaluating endpoints, which are the key results used to measure a trial’s success. This article explains the goals and different types of endpoints in clinical trials, the importance of patient-reported outcomes, and how to design better trials, especially for transplant patients.

Understanding Objectives and Endpoints

The main goal of a clinical trial is to see how well and safely a treatment works. Endpoints are the specific results or events used to measure the trial’s success. For example, in cancer trials, an endpoint might be a reduction in tumor size. In transplantation trials, it could be how well the new organ is working. Other general health indicators include survival rates and the severity of side effects.

Different Types of Endpoints

There are several types of endpoints in clinical trials:

• Primary Endpoints: The main results used to determine if the treatment is successful.
• Secondary Endpoints: Additional results that provide more information about the treatment’s effects or side effects.
• Exploratory Endpoints: Used to explore other potential outcomes and generate ideas for future research.
• Surrogate Endpoints: Substitute markers that are believed to indirectly reflect longer-term patient outcomes.

Surrogate endpoints are used when the primary endpoints take too long to measure. For example, lowering blood cholesterol might be used as a surrogate endpoint for preventing heart attacks.

Outcomes

Clinical outcomes (results) come from many sources. There are data collected from objective measures like an X-ray or a blood test.  Patient-reported outcomes (PROs) are one type of clinical outcome assessment becoming more important in clinical trials.

Others include clinician-reported outcomes (ClinROs), which are health assessments made by doctors, observer-reported outcomes (ObsROs), which are evaluations by care partners, and performance outcomes (PerfOs), which are measures of a patient’s ability to do certain tasks.

PROs are results based on what patients say about their own health, symptoms, and quality of life. Including PROs in trials helps make research more focused on the patient, enabling healthcare providers to understand the experimental drug’s benefits and side effects from their perspective.

Using PROs can greatly improve drug development by:

• Providing direct insights into the patient’s experience, leading to more patient-centered drug development.
• Identifying benefits or side effects that might not be seen through traditional measurements.
• Providing additional data that can aid in the approval process by showing clear benefits from the patient’s viewpoint.

Future Clinical Trials Design for Improved Outcomes After Transplantation

Designing better clinical trials for transplantation should focus on improving long-term patient and organ survival. This involves:

• Enhancing Endpoint Selection: Using a mix of traditional and new endpoints, including molecular and genetic markers, which allow for more precise tailoring of the response, to predict organ function and survival, as well as patient response and changes.
• Incorporating Comprehensive PROs: Including endpoints that reflect the patient’s quality of life after transplantation, which is very important in evaluating the success of the procedure.
• Utilizing Adaptive Trial Designs: These allow changes based on early results, potentially reducing costs and time, and improving the relevance and ethical aspects of the trials.

Conclusion

Rethinking endpoints in clinical trials is vital for advancing medical research and improving patient care. By including patient-reported outcomes and refining endpoint selection, especially in transplantation, researchers can achieve more meaningful and impactful results. Moving forward, clinical trial designs should better match the complexities of human health, ensuring new treatments and procedures are both effective and patient centered.

This article is made possible by the support of ITB-MED LLC. 

Glossary

Endpoints: The key results used to measure a trial’s success

Genetic Markers: Pieces of DNA that can provide information about a person’s risk for certain diseases or how they might respond to a treatment.

Molecular Markers: Tiny parts of cells, like proteins or DNA, that can give clues about how an organ is working or how a disease is progressing.