Scientist examining drug discovery vial with data matrix reflection, symbolizing reliable bioanalysis.

Drug Discovery's Quality Check: How Incurred Sample Reanalysis Boosts Confidence

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Lena Kashyap in Health & Wellness December 2025 • 4 min read.

"Ensuring reliable data in early-stage drug development with Incurred Sample Reanalysis (ISR) – a key strategy for robust bioanalysis and confident decision-making."


In the high-stakes world of drug discovery, generating accurate and reliable data is paramount. Bioanalysis, the process of measuring drug concentrations in biological samples, plays a crucial role in evaluating potential drug candidates. This data drives critical decisions, guiding researchers toward promising leads and away from dead ends.

However, the fast-paced nature of early-stage drug discovery can sometimes compromise the thoroughness of quality control. That's where Incurred Sample Reanalysis (ISR) comes in. ISR is a process of re-analyzing a subset of samples to verify the accuracy and reproducibility of the original results. This confirmation step helps ensure that the data used to make key decisions is robust and reliable.

This article will delve into the application of ISR in drug discovery bioanalysis. We'll explore how this strategy can be implemented to enhance the quality of data, optimize drug development, and ultimately increase the chances of success. We'll also look at how to introduce ISR strategy that enforces adequacy of controls in sampling, processing errors including differences in extraction recovery.

ISR: A Strategy for Reliable Bioanalysis

Scientist examining drug discovery vial with data matrix reflection, symbolizing reliable bioanalysis.

Incurred Sample Reanalysis (ISR) is not new. However, its usage in early drug discovery is. Traditionally, ISR is a regulated bioanalysis requirement. It is used to assess bioanalysis only after completion of every study when the drug enters drug development. ISR is now being proposed and used earlier in the development stage.

The primary goal of ISR is to confirm the reliability of the original bioanalytical data. By re-analyzing a portion of the samples, researchers can identify any potential issues with the analytical method, sample handling, or data processing. This helps to ensure that the data is accurate and can be confidently used for decision-making.

  • Enhanced Data Quality: ISR helps identify and correct errors, leading to more reliable pharmacokinetic data.
  • Informed Decision-Making: Confident data supports better decisions about which drug candidates to advance.
  • Optimized Development: Early detection of issues can save time and resources in the long run.
To implement an effective ISR strategy, a few key considerations must be addressed. These include: sample selection, acceptance criteria, and frequency of analysis. It's important to select samples that represent the full range of concentrations and time points, as well as samples that are critical for decision-making. Setting appropriate acceptance criteria for the re-analysis results is also crucial. Lastly, deciding how often to perform ISR will depend on the stage of drug discovery and the risk associated with the project.

The Future of ISR in Drug Discovery

As drug discovery continues to evolve, the importance of reliable data will only increase. ISR is a valuable tool for ensuring the quality of bioanalytical data and supporting informed decision-making. By embracing ISR, researchers can increase their confidence in the data, accelerate the drug development process, and ultimately improve the chances of success.

While implementing an ISR strategy adds workload, periodically planned ISR program, every 6 months, should enable a continuous review and improvement of laboratory related practices which in turn will have positive impact on the data driven decisions during drug discovery process.

The individual bioanalytical laboratory can draw an algorithm for selecting NCEs as well as the acceptance of the ISR data. For example, the regulatory guidance for developmental candidates recommends an ISR acceptance target for 67% of the repeat sample values to be contained within 20% of the original values (USFDA, 2018; EMA 2011).

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Everything You Need To Know

1

What is Incurred Sample Reanalysis and how does it work in drug discovery?

Incurred Sample Reanalysis, or ISR, is a method of re-analyzing a subset of biological samples. This is done to verify the accuracy and reproducibility of the initial results obtained during bioanalysis. This process helps to confirm the robustness and reliability of the data, ensuring that critical decisions in drug discovery are based on sound evidence.

2

What are the primary advantages of using Incurred Sample Reanalysis in early-stage drug development?

The main benefits of using Incurred Sample Reanalysis include enhanced data quality, which involves identifying and correcting errors in pharmacokinetic data. It also supports informed decision-making, which allows for better choices about which drug candidates to advance. Furthermore, it optimizes the overall development process by detecting issues early, which can save time and resources in the long run. It also enforces adequacy of controls in sampling, processing errors including differences in extraction recovery.

3

What are the key considerations for implementing an effective Incurred Sample Reanalysis strategy?

To implement Incurred Sample Reanalysis effectively, there are three key considerations to address. First is sample selection, where it's important to choose samples that represent the full range of concentrations and time points, focusing on those critical for decision-making. Next is acceptance criteria, which involves setting appropriate standards for the re-analysis results. Lastly is frequency of analysis, where deciding how often to perform ISR will depend on the stage of drug discovery and the risk associated with the project.

4

When is Incurred Sample Reanalysis traditionally used, and how is its application evolving in drug discovery?

Incurred Sample Reanalysis is usually used as a regulated bioanalysis requirement to assess bioanalysis after the completion of every study, when the drug enters drug development. Now, Incurred Sample Reanalysis is being proposed for use much earlier in the drug development stage. This allows for the confirmation of method reproducibility during the early stages of drug development.

5

What is the future of Incurred Sample Reanalysis in drug discovery, and what impact does it have on the overall success of the process?

As drug discovery progresses, the importance of reliable data will only increase. Incurred Sample Reanalysis serves as a valuable tool for ensuring the quality of bioanalytical data, and supports well-informed decision-making. By using Incurred Sample Reanalysis, researchers can be more confident in their data, accelerate the drug development timeline, and increase the probability of success. Without ISR, errors in early bioanalysis could lead to the misidentification of promising drug candidates or the wasteful pursuit of ineffective ones, resulting in significant financial and time costs.

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