Biomarkers for Clinical Trials
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As the use of biomarkers in clinical trials increases, the decision to use a biomarker in a trial needs to be taken in consideration
with the cost and value they bring. Patrice Hugo, PhD, VP Scientific Affairs, Global Central Lab, MDS Pharma Services, told
attendees of the recent IIR Central Labs Partnering Conference that the first thing any sponsor should do is clearly define
the intended use of the biomarker for its clinical trial.
"It is so important that it must be the first thing in the RFP," Hugo told Applied Clinical Trials. And it is important to take the time to specify the requirement, he notes, because of the impacts to the information that
biomarker use will bring in the clinical trial. To determine these critical and uncritical biomarkers at the outset of the
trial is crucial to cost control and experimental drug design. For example, critical biomarkers would be used to determine
exclusion/inclusion criteria, or used as a direct measure of drug efficacy being the primary surrogate endpoint. Said Hugo,
"In this case, the relationship between the clinical outcome and the biomarker is not necessarily perfect, but is good enough
to make a decision. For instance, CD4 count in HIV trials is a well-known surrogate endpoint." An uncritical biomarker, then,
is one that is not used to make immediate decisions in the trials. For example, it would bring insight into the disease or
the mechanism of the drug.
Role of the central lab
In addition, for the sponsor evaluating its cost/benefit to using a biomarker, the testing process is a factor. Hugo explained:
"Several biomarkers are measured by using high throughput technology platforms testing several samples at once and/or using
multiplex technologies where one sample is simultaneously tested for various markers at once." For those instances, he said,
it makes sense to batch the samples and only perform testing when a high enough number of samples are available. Although,
this reduces the cost, it is not always possible when the results are needed in a very short time frame after the patient
visit. Biomarker use has also changed the traditional role of a central lab. According to Hugo, central labs used to perform safety
testing almost exclusively. "Typically, safety testing requires high sample handling and logistics, short-term availability
of capacity, fast turn around time (i.e., usually less than 48 hours), large to very large volumes of samples, data comparability
between laboratory sites, and adequate regulatory accreditations and approvals," explained Hugo.
With the advent of biomarker and esoteric testing in central labs, new requirements or constraints include technology transfer
from sponsors, tailored designed assays, pushing technical specifications of commercially available kits, "fit-for-purpose
validation," ad hoc proficiency testing, increased logistics around frozen management and batched sample testing, and customized
analytical reports.
All food for thought for the sponsor partnering with a central lab in its biomarker forays.
