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Companion Diagnostics: Importance, Technologies, and Regulatory Landscape

Companion Diagnostics - Importance, Technologies, and Regulatory

Companion Diagnostics: Importance, Technologies, and Regulatory Landscape

What is companion diagnostics?

companion diagnostic refers to a type of medical test or assay that helps healthcare professionals determine the most appropriate treatment for individual patients. It involves the simultaneous development of both a therapeutic drug and a diagnostic test. The diagnostic test is designed to identify specific biomarkers based on genetic mutations or epigenetic traits in a patient’s body that are relevant to the use of the associated drug.

The main objective of companion diagnostics is to determine whether a particular patient is likely to benefit from a specific treatment or medication. By analyzing the patient’s genetic, epigenetic, or molecular profile, companion diagnostics can identify individuals who are more likely to respond positively to a particular therapy, while also identifying those who may experience adverse reactions or have a lower chance of responding to the treatment.

This personalized approach to medicine offers several advantages. It allows healthcare providers to make more informed decisions about treatment options, ensuring that patients receive therapies that are most likely to be effective for their specific condition. This can lead to improved patient outcomes and a higher likelihood of successful treatment.

Companion diagnostics also play a crucial role in the development of new drugs and therapies. By identifying specific genetic, epigenetic, or molecular markers associated with a disease, researchers can better understand the underlying mechanisms and design more targeted treatments. This helps to streamline the drug development process and increase the likelihood of successful clinical trials.

Moreover, companion diagnostics can contribute to a more efficient and cost-effective healthcare system. By identifying patients who are unlikely to benefit from a particular treatment, unnecessary expenses can be avoided, and patients can be spared from potential side effects or complications. This targeted approach reduces the burden on healthcare resources and ensures that resources are allocated where they are most needed.

However, it is important to note that companion diagnostics are not applicable to all medical treatments or conditions. They are primarily utilized in areas where there is a strong correlation between specific genetic or molecular markers and treatment response. Additionally, the development and implementation of companion diagnostics require rigorous scientific research, validation, and regulatory approval to ensure their accuracy, reliability, and clinical utility.

In summary, companion diagnostics are advanced medical tests that provide crucial information about a patient’s genetic or molecular profile, allowing healthcare providers to personalize treatment decisions. By identifying patients who are more likely to benefit from a particular therapy, companion diagnostics improve treatment outcomes, support drug development, and contribute to a more efficient healthcare system overall.

What is the difference between IVD and LDT?

IVD stands for In Vitro Diagnostic, while LDT stands for Laboratory-Developed Test. Here’s an explanation of the key differences between the two:

1. Definition and Regulation
An IVD refers to a diagnostic test or device that is commercially manufactured, validated, and marketed for diagnostic use. These tests are developed by manufacturers and are regulated by regulatory authorities, such as the U.S. Food and Drug Administration (FDA) in the United States, or the European Medicines Agency (EMEA) in Europe, to ensure their safety, effectiveness, and quality.

On the other hand, an LDT is a diagnostic test developed and performed within a single laboratory. LDTs are typically designed by laboratory professionals or researchers to meet specific testing needs. They are not commercially distributed or regulated as rigorously as IVDs.

2. Development and Validation
IVDs are developed by diagnostic companies, which involve extensive research, development, and validation processes. The manufacturers are responsible for demonstrating the analytical and clinical performance of the test through rigorous studies and obtaining regulatory clearance or approval before marketing the IVD.

LDTs, however, are developed within a laboratory, often to address a particular diagnostic challenge or fill a testing gap. Laboratories that develop LDTs are responsible for the entire development process, including assay design, optimization, and validation. While there may be some guidelines and recommendations to follow, LDTs generally have more flexibility in their development and validation compared to IVDs.

3. Regulatory Oversight
IVDs are subject to regulatory oversight by regulatory agencies such as the FDA. These agencies evaluate the performance, safety, and effectiveness of IVDs before they can be marketed and used in clinical practice. Manufacturers must adhere to specific regulatory requirements, including pre-market clearance or approval processes, quality control, and post-market surveillance.

LDTs, in contrast, are regulated in different ways depending on the country. In some regions, such as the United States, LDTs have historically been under the purview of laboratory regulation rather than direct FDA oversight. However, there has been ongoing discussion and evolving regulations surrounding LDTs in recent years, with efforts to establish a more comprehensive regulatory framework.

4. Availability and Distribution
IVDs are manufactured and distributed on a larger scale by diagnostic companies, allowing broader availability across various healthcare settings. They are often standardized, packaged, and provided with clear instructions for use.

LDTs, by contrast, are typically limited to the specific laboratory that developed them. These tests may not be widely available outside the originating laboratory or may be provided through collaborations or reference laboratory networks. The availability of LDTs can be more localized or limited to specific research or clinical settings.


It’s important to note that the regulatory landscape and oversight of IVDs and LDTs may vary between countries and regions. Regulations and requirements are subject to change, and it’s essential to consult local regulatory authorities and guidelines for the most up-to-date information.

What is the new IVDR?

The new IVDR refers to the In Vitro Diagnostic Regulation, which is a regulatory framework established by the European Union (EU) to govern in vitro diagnostic devices (IVDs). The IVDR is an updated and enhanced version of the previous In Vitro Diagnostic Directive (IVDD). It aims to strengthen the regulation of IVDs to ensure their safety, performance, and reliability, while also promoting innovation and harmonization within the EU.

The IVDR was adopted by the European Parliament and the Council of the European Union in 2017 and entered into force on May 26, 2017. However, it has a transitional period, and full application will start on May 26, 2022, providing manufacturers, notified bodies, and other stakeholders time to comply with the new requirements.

Key changes introduced by the IVDR include:

1. Risk-Based Classification
The IVDR introduces a new risk-based classification system for IVDs, which aligns with the risk categories specified in the Medical Device Regulation (MDR). This classification determines the level of scrutiny and conformity assessment procedures required for each IVD category.

2. Stricter Scrutiny and Conformity Assessment
The IVDR imposes more stringent requirements for the conformity assessment of IVDs. It emphasizes clinical evidence, performance evaluation, and post-market surveillance. Notified bodies play a crucial role in assessing and certifying the conformity of IVDs with the IVDR requirements.

3. Increased Clinical Evidence Requirements
The IVDR places greater emphasis on the availability and quality of clinical evidence to support the performance and safety claims of IVDs. Manufacturers are required to generate and provide clinical data, including clinical performance studies, analytical and clinical validation, and post-market clinical follow-up.

4. Unique Device Identification (UDI)
The IVDR mandates the use of a Unique Device Identification (UDI) system for IVDs to ensure traceability, enhance post-market surveillance, and facilitate device identification and recalls.

5. Strengthened Post-Market Surveillance (PMS)
The IVDR reinforces post-market surveillance requirements for IVD manufacturers. It includes more comprehensive and proactive monitoring of IVDs in the market, implementation of a post-market surveillance system, and reporting of serious incidents and field safety corrective actions.

6. Notified Body Oversight
The IVDR introduces stricter requirements for notified bodies, which are the designated organizations responsible for assessing the conformity of IVDs. Notified bodies must meet enhanced criteria for competence, independence, and transparency.

The IVDR aims to improve patient safety, ensure the reliability and accuracy of IVD results, and provide a robust regulatory framework for the rapidly evolving field of in vitro diagnostics. Manufacturers, notified bodies, healthcare professionals, and other stakeholders are working towards compliance with the IVDR requirements within the specified transition period.

What are the advantages of companion diagnostics?

Companion diagnostics offer several advantages in the field of healthcare and personalized medicine.
Some of the key advantages include:

1. Personalized Treatment Decisions
Companion diagnostics enable healthcare providers to tailor treatment decisions based on an individual patient’s (epi)genetic or molecular profile. By identifying specific markers associated with a disease, these tests can help determine the most appropriate treatment or therapy for each patient. This personalized approach improves the likelihood of treatment success and reduces the potential for adverse reactions.

2. Improved Patient Outcomes
By selecting treatments that are more likely to be effective for a particular patient, companion diagnostics can significantly improve patient outcomes. Patients receive therapies that are specifically matched to their disease characteristics, leading to better response rates, higher survival rates, and improved quality of life.

3. Avoidance of Ineffective Treatments
Companion diagnostics can identify patients who are unlikely to benefit from certain treatments. This prevents the administration of ineffective therapies, saving patients from unnecessary side effects, complications, and expenses. By avoiding futile treatments, healthcare resources can be allocated more efficiently to patients who have a higher chance of responding positively.

4. Streamlined Drug Development
In the context of drug development, companion diagnostics play a crucial role in the design and testing of new therapies. By identifying specific genetic or molecular markers associated with a disease, researchers can better understand the underlying mechanisms and develop targeted treatments. This targeted approach can accelerate the drug development process, increase the success rate of clinical trials, and bring innovative therapies to market faster.

5. Cost-Effectiveness
Companion diagnostics can contribute to a more cost-effective healthcare system. By identifying patients who are unlikely to benefit from certain treatments, unnecessary expenses can be avoided. This includes the costs associated with ineffective therapies, monitoring, and managing adverse events. Companion diagnostics help optimize the allocation of healthcare resources and reduce the economic burden on patients and healthcare systems.

6. Regulatory Compliance
The use of companion diagnostics can aid in regulatory compliance by ensuring that treatments are prescribed according to approved indications. Regulatory agencies often require the use of companion diagnostics in conjunction with certain medications to ensure patient safety and treatment efficacy. Adhering to these guidelines helps healthcare providers meet regulatory requirements and deliver high-quality, evidence-based care.


In conclusion, companion diagnostics offer several advantages, including personalized treatment decisions, improved patient outcomes, avoidance of ineffective treatments, streamlined drug development, cost-effectiveness, and regulatory compliance. By integrating genetic, epigenetic, or molecular information into medical decision-making, companion diagnostics pave the way for precision medicine and contribute to more effective, targeted, and efficient healthcare practices.

Epigenetics as a diagnostics biomarker

Epigenetics refers to the study of changes in gene expression that occur without alterations in the underlying DNA sequence. These epigenetic modifications can influence how genes are activated or silenced, thereby affecting cellular functions and contributing to various diseases and conditions.

Epigenetic markers, such as DNA methylation patterns, histone modifications, and non-coding RNA molecules, have shown great potential as biomarkers in several areas of healthcare. 

Here are some ways in which epigenetics can serve as biomarkers:

1. Disease Diagnosis and Prognosis
Epigenetic alterations can be specific to certain diseases or conditions. By analyzing epigenetic markers, healthcare professionals can potentially detect and diagnose diseases at early stages when treatment is more effective. Epigenetic biomarkers can also provide insights into disease prognosis, helping predict disease progression and patient outcomes.

2. Predicting Treatment Response
Epigenetic biomarkers can help predict a patient’s response to specific treatments. For example, in cancer, certain DNA methylation patterns can indicate whether a tumor is likely to respond to chemotherapy or targeted therapies. By identifying these biomarkers, healthcare providers can select the most appropriate treatment options and avoid ineffective or potentially harmful therapies.

3. Monitoring Disease Progression
Epigenetic changes can occur during the course of disease progression. Monitoring epigenetic biomarkers over time can provide valuable information about disease evolution, allowing for adjustments in treatment strategies. This dynamic monitoring can be particularly useful in cancer, where tumors can acquire new epigenetic modifications that impact treatment response.

4. Early Detection of Cancer
Epigenetic alterations can occur in the early stages of cancer development, even before clinical symptoms appear. This offers the potential for early cancer detection through non-invasive methods, such as analyzing DNA methylation patterns in blood samples or other body fluids. Early detection allows for timely interventions and improves the chances of successful treatment.

5. Risk Assessment
Epigenetic biomarkers can help assess an individual’s predisposition to certain diseases or conditions. By studying epigenetic patterns in large population studies, researchers can identify associations between specific epigenetic modifications and disease risk. This information can be used for risk assessment, personalized screening strategies, and preventive interventions.

6. Environmental Exposure Assessment
Epigenetic modifications can be influenced by environmental factors, such as toxins, pollutants, diet, and lifestyle choices. Analyzing epigenetic changes can provide insights into an individual’s exposure history and its potential impact on health. This information can help identify environmental risk factors, guide public health policies, and promote healthier living environments.

Epigenetic biomarkers hold great promise, yet further research is needed to validate their clinical utility, establish standardized methodologies for their analysis, and address ethical considerations. Also, the location of the epigenetic marks is a very important aspect to consider. However, as our understanding of epigenetics continues to grow, the use of epigenetic biomarkers is likely to play an increasingly important role in disease diagnosis, treatment decision-making, and personalized healthcare.

What technologies are used for companion diagnostics?

Companion diagnostic testing typically involves a combination of advanced technologies to analyze the genetic or molecular markers relevant to a particular disease or treatment. The specific technologies employed can vary depending on the nature of the biomarkers and the intended purpose of the test. Here are some commonly used technologies in companion diagnostic testing:

1. Polymerase Chain Reaction (PCR)
PCR is a widely used technique that amplifies specific DNA or RNA sequences, allowing for their detection and analysis. It is commonly employed in companion diagnostic testing to identify and quantify genetic mutations or variations associated with a disease or treatment response.

2. Next-Generation Sequencing (NGS)
NGS technologies enable the rapid sequencing of large amounts of DNA or RNA, providing comprehensive genetic information. NGS is particularly useful for identifying genetic mutations, gene expression patterns, and genomic rearrangements that can guide treatment decisions in companion diagnostics.

3. Immunohistochemistry (IHC)
IHC is a technique used to visualize specific proteins in tissue samples. Antibodies labeled with fluorescent dyes or enzymes are used to target and detect specific proteins of interest. IHC is commonly employed in companion diagnostic testing to determine protein expression levels or the presence of specific biomarkers in tissue samples.

4. Fluorescence In Situ Hybridization (FISH)
FISH is a technique used to visualize and detect specific DNA or RNA sequences in cells or tissue samples. It involves labeling DNA or RNA probes with fluorescent dyes that specifically bind to the target sequences. FISH is often used in companion diagnostics to detect gene amplifications, chromosomal rearrangements, or specific gene fusions.

5. Mass Spectrometry
Mass spectrometry is a technique used to measure the mass and charge of molecules. It is commonly employed in companion diagnostics to analyze proteins or metabolites in biological samples. Mass spectrometry-based approaches, such as proteomics or metabolomics, can provide valuable insights into disease mechanisms and treatment responses.

6. Microarrays
Microarray technology allows for the simultaneous analysis of thousands of DNA or RNA sequences. It involves immobilizing specific probes on a solid surface, which then hybridize with complementary target sequences in the sample. Microarrays can be used in companion diagnostic testing to analyze gene expression patterns, detect genetic variations, or identify epigenetic modifications.


It’s important to note that companion diagnostic testing may involve a combination of these technologies or other emerging technologies depending on the specific biomarkers being analyzed. The selection of the appropriate technology is based on factors such as the type of biomarker, sample type, throughput requirements, and sensitivity needed for accurate detection and analysis.

Companion diagnostic services with

At, we specialize in cutting-edge companion diagnostics services, harnessing the power of disease-related methylation changes as potent biomarkers throughout the clinical disease management process. Our expertise extends from early screening and diagnosis to risk assessment, prognosis, treatment, and chronic disease monitoring. We recognize the pivotal role that epigenetic biomarkers play in advancing personalized patient care within the realm of precision medicine, an aspect often overlooked in today’s healthcare landscape.

In a landscape where only a fraction of the vast scientific knowledge on DNA methylation-based biomarkers has been translated into commercially available clinical tests, stands out. With a foundation rooted in our epigenetics labs, our experts boast a proven track record in epigenetic assay development, demonstrating market success. Overcoming methodological and experimental obstacles, our unique expertise in optimal assay design ensures the translation of genome-wide or array-based epigenetic data into robust routine proof tests, such as the MSP format.

Whether starting from your epigenetic data or your samples, offers tailored solutions:

Your epigenetic data as a starting point:

After intensive review, defines the optimal route for robust and simplified assay development. This includes model optimization or a de novo machine learning approach, focusing on alternative algorithms and signatures.

Your samples as a starting point:

Leveraging a state-of-the-art discovery platform and computational biology expertise, conducts top-notch methylation profiling analysis. The optimal epigenetic biomarkers are selected and validated against the related genes or pathways of the event in focus. Genome-wide or array-based epigenetic data is seamlessly translated into simplified routine proof tests like MSP formats.

Full companion diagnostic integrated solution:

Our full companion diagnostic integrated solution is sample-type and disorder-agnostic. supports diverse domains, including oncology, neurology, and infectious diseases. With our in-house experts, we craft an efficient companion diagnostic development program with a focus on your success:

  • Biomarker discovery, selection, and validation
  • Biomarker competitive strategy
  • Assay prototype building
  • Assay validation

Multi-Omics biomarker assays:

As companion diagnostics gain prominence in tandem with targeted and precision therapies, stands at the forefront. With high expertise in multi-omic biomarker development and data science, we house state-of-the-art platforms, nurturing biomarkers from biological samples to market-proof and competitive assays. Big data analysis of relevant data groups further strengthens our capabilities.


In collaboration with, you’re not just accessing diagnostic services, you’re unlocking the potential of companion diagnostics to guide personalized therapeutic treatments. Our commitment to quality, excellence, and innovation ensures that your research endeavors in precision medicine reach new heights. 

Feel free to connect with our team for inquiries or discussions on potential collaborations through the form below. Together, we can drive scientific advancements that reshape the landscape of companion diagnostics and healthcare.

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