Whether it is about assessing eligibility criteria, safety monitoring, determining baseline, or demonstrating the efficacy of the drug under investigation, laboratory testing of multiple clinical, immunological, and in certain studies, genetic biomarkers is an integral part of clinical trials.
Earlier, most clinical trial laboratory testing was done by local laboratories that were organized by individual principal investigators. Collecting data from multiple local laboratories that used different testing methodologies, reference ranges, and standard operating procedures (SOPs) was associated with data errors, resulting in delays and increased costs for sponsors. Mislabeled kits, missing samples, and incorrect tests were common. The laboratory data received at the end of a clinical trial often had a very high error rate. This scenario became much more complex as trials became globalized. Analysis of data with such inaccuracies led to months of work cleaning the data in order to make it analyzable.
The central laboratory concept was first implemented in the mid-1980s, driven by the need to deliver consistency in collection and uniform standards of reporting, as well as consolidation of test results and data from different sites. A central laboratory is an institution that is exclusively responsible for laboratory assessments and provides services ranging from conducting laboratory assessments and compiling lab test reports to contracting courier services for delivering lab kits and biosamples to and from medical institutions where diagnosis and treatment of patients are performed.
The value that central labs add compared to high-volume diagnostic labs is due to consistency across all aspects of laboratory functionality, starting from uniform specimen collection kits to standard analytical method platforms that follow customary SOPs, equipment, reagents, and standards. Non-standardization of these parameters leads to variability and inconsistency in results. For example, standardization of a lab collection kit enhances ease of use for those who perform the actual collection of samples. Central labs train site staff on proper collection, packaging, and labeling requirements, thereby reducing human errors that can lead to misidentification and incorrect reporting of samples. Central laboratories standardize the selection of appropriate analytical methods and equipment that indicate suitable blood volume to be collected, and they also standardize final report formats.
Central laboratories have professional logistics teams that understand sponsor requirements and establish relationships with courier agencies. Logistics arrangements take into account requirements such as dry ice and ensure that shipments take place under desired conditions. They have customized tracking systems that provide visibility of specimens while in transit. Central labs have uniform SOPs in place, IT platforms, and QA standards, and can provide data in a single file format using set reference ranges and units as required by the sponsor. Central laboratories are familiar with regulatory requirements across different geographies and strive to stay informed about changes in the regulatory environment.
Central labs deliver globally harmonized, statistically meaningful data that provide consistency over time, while diagnostic labs provide individual snapshots of lab results. Diagnostic laboratories cannot provide solutions for global clinical trials, have limited scalability, and need to adjust to diagnostic laboratory priorities where decisions are driven by cost-effectiveness of diagnostic testing rather than maintaining the consistency required for pharmaceutical-grade testing.
These observations reinforce the role of central laboratories in clinical trials.