Advances in Liquid Biopsy Research for Disease Detection, Diagnosis, and Treatment and What the Future May Hold

1. Can you elaborate on the transformative potential of liquid biopsy in revolutionizing disease diagnostics, especially in comparison to traditional biopsy methods?

Liquid biopsies offer several advantages over traditional biopsies. They are minimally invasive; the sample can be obtained from a simple blood draw and does not require an incision or tissue sample. Also, administering traditional tissue biopsies can lead to excessive bleeding, infection or less likely but possible spreading of cancer cells throughout the body.

Liquid biopsies can provide more comprehensive information about the disease burden than tissue biopsies. They can detect circulating cancer cells or genetic signatures before they form a primary tumor. This allows doctors to learn more about the cancer and any mutations that may be present throughout the body, not just at one site, at a time when they would be difficult to detect with imaging techniques.

The data obtained from liquid biopsies can be used to inform diagnoses and provide more precise treatment options. Due to their ease of collection, liquid biopsies provide an opportunity for serial sampling, enabling ongoing monitoring of a patient’s response to treatment or disease recurrence.

Liquid biopsies also give researchers access to longitudinal data, allowing them to study the evolution of drug resistance and development of the metastatic state with the goal of improving future treatment options.

Compared to traditional biopsies, liquid biopsies also have a much shorter turnaround time. Traditional biopsies can take days or weeks to process and analyze, whereas liquid biopsies can provide results in as little as 24 hours. This shorter turnaround time can help physicians make quicker decisions about treatment options and sponsors decide whether to move forward with clinical trials for a new drug candidate.

2. How has the integration of next-generation sequencing (NGS) and other cutting-edge technologies improved the precision and accuracy of liquid biopsy, particularly in detecting rare genetic mutations?

The barriers to liquid biopsies clinical utility center on the low abundance of circulating tumor DNA (ctDNA), which causes many sensitivity and specificity challenges. However, researchers are seeing benefits from using a multi-analyte approach. By simultaneously targeting multiple biomarkers, studies have demonstrated improved assay sensitivity for the detection of mutations as well as the potential to uncover therapy-resistant genes.

Some recent examples of this multi-analyte approach include the CancerSEEK platform, which screens for up to nine cancers by detecting eight unique proteins and oncogenic mutations using ctDNA. The OneTest platform uses machine learning and proteomics to screen for up to six cancers. Targeting multiple biomarkers has the potential to significantly enhance the efficacy of screening for cancers at an early, treatable stage.

3. In your view, what specific advancements in liquid biopsy have shown promising results in the early detection of cancers, and how do these findings impact the overall diagnostic landscape?

One of the most exciting advancements pertains to increasing the sensitivity of liquid biopsies using a priming agent. False negatives have been a constant challenge for the industry due to the low levels of target analytes. Cell free assays must detect tiny amounts of target DNA or RNA, which may be as low as two or three molecules in each tube of blood. Researchers at MIT and the Broad Institute of MIT and Harvard have developed two types of injectable molecules or priming agents that can be used to temporarily slow down the clearing of tumor DNA from the bloodstream and effectively boost that signal.2 Their work is still in the early phases of testing and development, but it holds a lot of promise for improving early cancer detection.   

As the volume of tumor-derived signals in a tube of blood is very small, techniques need to be developed that can increase the amount of information that can be gleaned from it. Recent approaches based on epigenetics, transcriptomics, and proteomics data are showing promising results that could lead to improved sensitivity and specificity of liquid biopsy tests in certain clinical contexts. By including additional patterns and insights identified by using artificial intelligence (AI), it is possible to get more answers from a single blood draw. By taking a multi-modal analytical approach to liquid biopsy development, we can provide patients and healthcare providers with faster, less expensive, and more flexible approaches.

4. Could you discuss a notable example or case study where liquid biopsy played a pivotal role in monitoring treatment response and guiding the implementation of personalized therapeutic strategies?

Labcorp’s Plasma Focus liquid biopsy test was recently brought to market and helps oncologists to develop targeted, personalized treatment plans for their patients with advanced solid cancers. Requiring only a standard blood draw, this test compares cell-free DNA released by tumor cells against a highly curated gene panel that focuses on U.S. Food and Drug Administration (FDA-) approved biomarkers. It was developed to help improve outcomes for patients with non-small cell lung, colorectal, breast, esophageal, gastroesophageal junction, gastric cancers and melanoma.

5. What key challenges in terms of sensitivity and standardization must be addressed to bridge the gap between liquid biopsy research and widespread clinical implementation?

Members of academia, industry, and government agencies are all acutely aware of the gaps in standardization practices. As a result, many of them have joined consortiums and are working together to better define standards and improve the clinical utility of precision medicine.

One such group, BLOODPAC, recognized the challenges involved in liquid biopsy development and standardization. It has established Minimum Technical Data Elements (MTDEs), which reflect factors that influence the performance of a liquid biopsy test in the laboratory and may affect the results for different areas of test validation. These MTDEs enable researchers to compare data sets across studies, draw important conclusions about the impact of specific pre-analytical variables, and (not to be overlooked) present a common vocabulary to ensure terms are used consistently and with appropriate meaning.

In addition, industry stakeholders such as the International Society of Liquid Biopsy and the European Society for Medical Oncology have been establishing guidelines for specimen handling, processing, and storage. These guidelines aim to ensure that samples are collected and processed consistently across different laboratories, enabling results to be compared between studies.

Another challenge that has been raised in the development of liquid biopsies focuses on experimental design. When comparing study results, there is some evidence that prospective cases show higher sensitivity than retrospective studies. This finding has been attributed to there being a high proportion of false negatives in retrospective studies. As the industry endeavors to accelerate development in this area, it needs to obtain results from prospective studies that more closely mirror the real-world diagnostic workflow.

6. Looking ahead, how might liquid biopsy technologies evolve to address not only cancer but also other disease areas, and what implications could this have for preventive healthcare?

While it is still early days, there has been an uptick in discussions about the application of liquid biopsies for central nervous system - related diseases. There are many lessons learned from studying cancer biomarkers that can help in advancing the early detection of Alzheimer’s, Parkinson’s and other neurodegenerative diseases. Both early detection and surveillance of neurological disorders can benefit from the fast and non-invasive nature of liquid biopsy assays. As population’s worldwide age and the incidence of neurological diseases rises, identifying biomarkers that can help to diagnose those conditions and inform treatment options has become an urgent need.

Research into cerebrospinal fluid (CSF) biomarkers for neurological disease has been progressing steadily over the past decade. Some of these targets go beyond the traditional cell-free DNA and include extracellular vesicles (exosomes, microvesicles, and apoptotic bodies), microRNA, and other nucleic acid derivatives. Some researchers are investigating a combination approach with CSF and blood-based biomarkers. Roche, in collaboration with Eli Lilly, is developing a blood-based liquid biopsy test to facilitate earlier diagnosis of Alzheimer’s disease, the Elecsys Amyloid Plasma Panel.

As more effective treatment options become available for these neurodegenerative diseases, it is critical that improved diagnostics are brought to market to streamline the path to diagnosis.

7. How do you envision the ethical considerations surrounding liquid biopsy evolving, and what regulatory frameworks should be in place to ensure responsible and equitable deployment in clinical practice?

Research shows significant racial and income disparities with respect to access to genomic profiling for cancer treatment selection. However, liquid biopsies offer the future potential to reduce these gaps in usage and improve access due to their minimally invasive nature. They will enable improved testing compliance by minimizing the burden of repeat hospital/clinic visits and attendant travel expenses, requisite time off work, and childcare costs. Liquid biopsies also allow the use of alternative care delivery models, e.g., direct-to-patient via mobile phlebotomy services, or blood draws during doctor visits, which may eliminate barriers for patients who face transportation roadblocks. They could also help to reduce geographic healthcare challenges in rural communities.

In terms of regulatory issues, one of the greatest challenges facing liquid biopsy usage today is broadening accessibility through more consistent payer coverage. While some states have passed legislation requiring health plans to cover biomarker tests, including some liquid biopsy assays, that meet certain evidentiary requirements, many US states have not passed any minimum coverage laws. This problem is not specific to the US. In the European Union, the usage of liquid biopsies seems to be limited to clinical trials or research in high-income countries, and not in low- or middle-income countries. It is critical that advancements proceed at a rapid pace to continue to generate clinical evidence in support of the validity of these assays.
 
8. Can you share an example of a successful interdisciplinary collaboration that significantly advanced liquid biopsy research, and what lessons can be drawn from such collaborations for future endeavors?

One example is the ctDNA for Monitoring Treatment Response (ctMoniTR) project that was facilitated through Friends of Cancer Research. This project succeeded in bringing together data from multiple, independent studies (spanning non-profits, academia, industry, and government) which accelerated their ability to generate robust analyses as a collective organization. The groups came together to answer one principal question, “Do changes in ctDNA reflect response to treatment?”

They were able to harmonize data across eight clinical trials and observe an important clinical finding that for patients with non-small cell lung cancer (NSCLC), who were treated with immune checkpoint inhibitors, reductions in ctDNA levels on treatment (detected via liquid biopsy) were associated with improved overall survival. While this interdisciplinary collaboration initially focused on NSCLC, the group intends to extend its study to include additional tumor types, stages, and drug classes.

9. From your perspective, how has industry involvement accelerated the development and commercialization of liquid biopsy technologies, and what challenges persist in achieving widespread accessibility?

Accounting for diversity in clinical trials has taken center stage in the past few years.

Researchers and companies seeking approval for late-stage clinical trials are now required to submit a plan for ensuring diversity among trial participants to the FDA. This requirement highlights both the need and urgency to overcome barriers to ensure appropriate patient groups are participating in clinical studies. Although this has become an important policy priority, progress has largely stalled on improving the participation of minority population groups. We need to make inroads, particularly as liquid biopsies become more widely available, in designing equitable clinical research programs that match the demographics of the disease.

I believe diversity plans need to be included earlier in the diagnostic development workflow where there are opportunities to gain insights into demographic-driven factors. It is critical that researchers assess the impact that diversity may have on their diagnostic’s sensitivity and accuracy during the preclinical phases of discovery and development, rather than at later-stage clinical validation.

As the population diversifies organically, there is a greater need and urgency to support generalization of findings. With enhanced preclinical data from diverse cohorts (that represent the disease incidence), there is more informed development of clinical guidelines.

The genetic, proteomic, and epigenetic profiles of populations can vary significantly with age, race and gender. Without early-stage assessment of these factors, unique targets can go unnoticed/undiscovered, minimizing the potential opportunities for precision medicine.

Finally, compiling representative data can help in gaining trust and educating the patients that are most critical for clinical trial enrollment. Presenting scientific evidence that is applicable and relevant can have a tremendous positive impact and highlight the value of participation.

10. In promoting public awareness and understanding, what key messages should be conveyed about the capabilities and potential impact of liquid biopsy, and what steps can be taken to ensure broader acceptance within the medical community and beyond?

Public awareness of liquid biopsies needs to improve in two areas. First, we must ensure that the patient populations which have the most to gain from these novel assays are educated on their availability and value. Patients need to understand the potential risks, benefits and common misconceptions surrounding these tests. Second, physicians must be informed about the availability and appropriate use of these tests and how to discuss them with their patients.
Physicians must continue to receive new evidence demonstrating the reliability of existing and emerging liquid biopsy technologies in cancer care. It is critical that they receive use cases and interpretation of data that can complement or provide alternatives to the standard of care. To achieve this, a coordinated effort needs to be made by assay developers, government, research associations and patient advocacy groups to provide guidance and education on the best approach for integrating liquid biopsy testing into traditional cancer treatment programs.

11. Considering the advancements, challenges, and future prospects we've discussed, what overarching message or insight would you like to leave our audience with regarding the role of liquid biopsy in transforming disease detection, diagnosis, and treatment, and its potential impact on the future of healthcare?

Given the enormous potential these assays hold for improving standard of care with a less invasive approach, we will continue to see rapid advances to broaden accessibility and use cases with the technology. As we are just scratching the surface regarding utilization of AI, I believe that will be the next big step forward with algorithms seeking out patterns and associations in multi-omics datasets. With this, I expect to see further adoption of liquid biopsies to improve cancer care and support personalized medicine approaches.

References

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10591039/
2. https://news.mit.edu/2024/researchers-improve-blood-tests-ability-detect-monitor-cancer-0118
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8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7158216/
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14. https://friendsofcancerresearch.org/wp-content/uploads/ctMoniTR_Step-2_Module-1_Findings.pdf?eType=ActivityDefinitionInstance&eId=99b8e3fc-1bfa-4d02-bd3f-1d780ef428da&eType=EmailBlastContent&eId=c2712dcd-e1c2-49a9-ade8-0ce8a9d1d56e
15. https://ascopubs.org/doi/full/10.1200/PO.21.00372?eId=031edfc7-2d9f-4889-80fe-0e495b16b687&eType=EmailBlastContent
16. https://ascopubs.org/doi/10.1200/PO.23.00382

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