It’s a big question to answer, but we’re providing some insights on how biomarkers can help move cell and gene therapies forward, and emphasizing the critical role of patient advocacy groups in shaping outcome measures.
Listen to Quick Takes from experts in the community on the following questions (Time: 18 min)
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What exactly is a biomarker and how do they differ from other outcome measures?
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What’s the hype – why should we be excited about the use of biomarkers in cell and gene therapy trials? But also, why do we need to temper this excitement?
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What’s the biggest challenge you face when trying to validate a biomarker in rare disease trials?
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How do you make sure the biomarkers you use in trials actually reflect what matters to patients and families? What can patient advocacy groups do right now to help this process?
Key Takeaways
What Is a Biomarker?
A biomarker is a measurable indicator of how a person’s body is functioning — either in health or disease. In the context of drug development, biomarkers can help assess whether a therapy is having its intended biological effect. Biomarkers are not the same as traditional functional outcomes, such as improvements in daily acts of living like walking or sleeping. Instead they offer faster insights that can be measured to understand a response to treatment with the goal of impacting how the person functions.
Why Are Biomarkers Exciting in Cell and Gene Therapy?
They provide real-time, measurable feedback on whether a treatment is working, and can accelerate the drug development timeline compared to complex, long-term functional outcome measures. Because they are more easily measured through a blood or urine sample, they have the may be more reproducible and reliable for drug approval. Two examples include:
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In more common diseases, it could be tracking cholesterol levels when using statins instead of waiting to see if someone avoids a heart attack.
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In a gene therapy for mucopolysaccharidosis (MPS), tracking levels of heparan sulfate in cerebrospinal fluid or urine can offer early evidence of therapeutic effect—well before changes in neurological function or behavior are observable.
Challenges in Using Biomarkers for Rare Diseases
Many rare diseases are genetically defined, so researchers often know where to look for relevant biomarkers. However, it can be difficult to gather enough patient samples to validate biomarkers due to small, scattered populations. Biomarkers are helpful, but don’t always predict real-world clinical benefits that patients would find most important, so care is needed in selection and interpretation.
The Importance of Validation and Patient Relevance
Validation involves linking the biomarker to a clinically meaningful outcome (e.g., walking, seizure reduction, quality of life). Researchers must engage patients and advocacy groups to define what outcomes matter most — this ensures the biomarker reflects real patient priorities.
How Advocacy Groups Can Help
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Sample Collection: Help coordinate and share precious biological samples responsibly and openly with researchers.
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Patient-Reported Outcomes (PROs): Collect and define what meaningful change looks like from a patient/family perspective. This must start early, ideally years before trials, to allow researchers enough time to study the link between desired patient outcomes and how to measure this.
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Planning Ahead: If advocacy groups wait until late in development to identify what matters, it may be too late to integrate meaningful biomarkers into trials.
Continuing the Journey
Check out more of our educational resources on other important topics:
Call to Action
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