Liquid biopsy is a blood test that measures pieces of tumours in a patient’s blood - as opposed to taking a piece of the tumour itself in tissue biopsy.

There are four major use cases for liquid biopsy:

1. Therapy selection, where biomarker profiling of the tumour enables using a more targeted therapy

2. Minimal residual disease (MRD) measurement, where cancer levels are measured to identify patients with where a “watch and wait” approach could be appropriate, understand patient response to a therapy or to watch for cancer recurrence during remission

3. Cancer screening to identify malignancies in asymptomatic individuals

4. A variety of non-oncology settings, e.g., prenatal screening for genomic anomalies

II: Is it likely to become mainstream?

Funds from financial investors are pouring into companies like Guardant Health, Natera and Illumina, reflecting a bullish sentiment around the liquid biopsy market. This is fueled by several factors:

• Increasing support from regulators, most importantly demonstrated by FDA’s 2022 guidance document “Use of Circulating Tumor DNA for Early-Stage Solid Tumor Drug Development”

• Increasing number of oncology trials using liquid biopsy

• Clear advantages of liquid biopsy over other diagnostics methods (especially low invasiveness, repeatability, speed of results, ability to biopsy tumours where tissue is not reachable)

• Upcoming launch of multiple key products, most importantly Guardant Health’s Shield (reimbursed early stage colorectal cancer screening test) which could potentially be a watershed moment for wide-spread screening

III: What could this mean for biopharma?

Liquid biopsy going mainstream may have several implications that biopharma companies are already starting to prepare for.

• Identify opportunities to benefit from liquid biopsy - e.g., improve treatment and trial experience, accelerate trial execution (surrogate markers enable earlier go/no-go decisions)

• Understand potential new patient pathways - especially as a result of more wide-spread screening (reimbursed and self-paid; single-target and multi-cancer).

• Prepare for changing patient expectations - e.g., on transparency of prognosis (which could be inferred from liquid biopsy tests)

• Consider partnering with select liquid biopsy companies to build competitive advantage, e.g., in developing targeted oncology products

Read more/ sources:

• Liquid Biopsy: A Distinctive Approach to the Diagnosis and Prognosis of Cancer

• Trends in the use of liquid biopsy in oncology

• How liquid biopsies are transforming precision cancer care

• Liquid biopsy: from concept to clinical application - Scientific Reports

• Liquid biopsy epigenomic profiling for cancer subtyping - Nature Medicine

• The Expanding Potential of Liquid Biopsy to Detect and Monitor Cancer 

• Challenges and achievements of liquid biopsy technologies employed in early breast cancer

• Investor presentations of Guardant Health, Illumina