[DR. SUSAN MCCUNE] Hello, I’m Dr. Susan McCune.
In this module, I’ll discuss some ways that biomarkers are being used generally to improve
drug development.
Biomarkers are playing an increasingly important role in drug development.
They can help improve clinical trial efficacy and reduce uncertainty in regulatory decision making.
But before we look at how biomarkers are improving drug development, it’s worth noting some
of the ways biomarkers are used in other scientific settings.
Clinical biomarkers are used every day in health care.
For example, some people track their blood pressure—a biomarker for cardiovascular health.
Other people test their blood glucose levels as a biomarker to make sure their diabetes
is under control.
Biomarkers improve health through novel means of diagnosing disease and providing ways to
determine responses to new treatments.
Biomarkers have the potential to enhance public health through a better understanding of diseases
and treatments.
In addition to their use in everyday health care, biomarkers are important in the drug
development paradigm.
Drug development is really a continuum, starting with basic research and extending through
drug discovery, preclinical development, clinical development, and post-market safety assessments.
Biomarkers are routinely used across this continuum in studies to support drug approvals.
For example, biomarkers can help to predict patients who might respond better to a drug
from a safety or efficacy perspective, monitor the safety of a therapy, or determine if a
treatment is having the desired effect on the body.
Biomarker-based strategies allow for a more biology-targeted approach to drug development
and may enable time and cost savings through leaner, more focused clinical trials that
have a higher overall probability of success with respect to both efficacy and safety.
Let’s take a closer look at the role biomarkers play at different points in the drug development
continuum.
In the early stages of drug development and preclinical testing, biomarkers may help to
identify molecular pathways that contribute to disease.
During prototype design, biomarkers can be used to identify the mechanism of action of
a drug or help in selection of the drug target.
In the preclinical development phase, biomarkers can be used in preclinical safety assessments,
in identifying the mechanism of action of the drug, or in helping with dose selection.
Biomarkers can serve a wide range of functions in clinical trials, including stratification,
patient selection, dose selection, trial enrichment, safety assessments, and efficacy assessments.
Here are some examples: As an example of patient selection, galactomannan
may be used as a diagnostic biomarker to classify patients as having probable invasive aspergillosis
for enrollment into clinical trials of antifungal agents to treat invasive aspergillosis.
As an example of a safety biomarker, hepatic aminotransferases may be used as safety biomarkers
when evaluating potential liver toxicity.
As an example of a response/efficacy biomarker, HIV viral load may be used as a pharmacodynamic
or response biomarker when evaluating response to antiretroviral treatment.
As an example of a monitoring biomarker, hepatitis C virus ribonucleic acid (HCV-RNA)
may be used as a monitoring biomarker when assessing patients with chronic hepatitis C to evaluate
disease status or burden.
The convention in clinical research has been to measure the performance of novel therapies
using clinical outcomes, such as mortality or disease progression.
But accruing enough information to support clinical endpoints in a trial of a new drug
may take many years.
Some biomarkers can predict drug efficacy more quickly than conventional clinical endpoints.
They have the potential to accelerate product development in certain disease areas, but
the amount of data needed to understand these biomarkers as surrogate endpoints is much
higher than the amount of data needed to support use of an enrichment biomarker.
FDA has approved multiple drugs on the basis of biomarkers used as outcomes in clinical trials.
CDER has published a table of biomarkers, categorized by therapeutic area, that have
supported approvals of new molecular entities, NMEs, and new biological therapeutics in CDER between
October 2007 and December 2015.
FDA recognizes biomarker development as a high priority area for future research and
collaboration among stakeholders and is taking action to better understand biomarkers used
in drug development.
Qualified biomarkers have the potential to provide valuable information that could reduce
uncertainty in regulatory decisions at each stage of the drug development process.
CDER’s Biomarker Qualification Program strives to make biomarker data publicly available
by establishing a biomarker’s value for a particular context of use in drug development
and regulatory review.
Once qualified, a biomarker can be used in multiple drug development programs
without a need for CDER to reconfirm the suitability of the biomarker for that specific qualified
context of use.
This program has the potential to advance public health by using biomarkers to streamline
the drug development paradigm.
We encourage drug sponsors to consult with the relevant review division as early as possible
in drug development regarding the use of biomarkers in their planned clinical trials.
Please consult CDER’s website to learn more about biomarkers and to access additional
information about biomarker qualification.