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An Inflection Point for High-Quality Diagnostic Tests in Oncology

In recent years, there has been a tidal wave of innovation in oncology with newly developed therapies and technologies profoundly changing how cancer patients are diagnosed, treated and monitored. So far, scientists have classified more than 100 types of cancer, and discovered myriad genetic mutations underlying them. Our understanding of these mutations is fueling innovation, and oncologists are now able to more precisely deliver care based on the individual patient’s disease. But precision cancer care can only be as good as the quality of the tests used to guide diagnosis and treatment.

What makes a test high-quality?

The promise of precision cancer care lies in the ability to tailor treatment options based on the unique traits of an individual’s cancer. To do this well, the quality of a diagnostic test is of the utmost importance. A high-quality test can accurately identify the biomarkers driving a patient’s cancer and predict potential treatment response using a clinically validated approach. The clinical laboratory running the test prioritizes quality assurance and quality controls, providing the highest quality genomic information and ensuring the highest standard of safety and care. Additionally, the test’s report provides timely, comprehensive and clinically actionable data to enable confident care decisions.

The value of companion diagnostic tests

An example of a high-quality test is a companion diagnostic, which undergoes extensive testing and rigorous review by the U.S. Food and Drug Administration (FDA) prior to being available on the market. As part of this review, a companion diagnostic is clinically proven to accurately and reliably identify patients that are most likely to benefit from an FDA-approved therapy. A companion diagnostic often supplies the only information a provider has that can direct precision cancer care and should be of the highest quality with well-proven technical and clinical performance.

Tests that do not meet this bar – which may be inaccurate or of unknown reliability or quality – could cause a patient to miss out on a potentially effective therapy or be exposed to side effects, toxicity, treatment delays, and costs from an ineffective therapy.[1]

For example, in a study of patients with early-stage lung cancer who received comprehensive genomic profiling, results are immediately available to inform immediate adjuvant therapy selection and specifically, immunotherapy avoidance when appropriate. Those patient results were also found to enable quality care upon recurrence with 17-day faster therapy initiation when FoundationOne®CDx testing occurred before recurrence compared to after. This emerging testing pattern is estimated to reduce total cost of care by $1,597.23 per patient compared to single-gene testing, a cost savings driven by the identification of ineffective and costly therapies.[1]

The U.S. is facing an inflection point

As science advances, a test’s quality will play a pivotal role in whether patients and physicians receive accurate and reliable information to inform a diagnosis, disease progression and treatment options. We are at an inflection point where the U.S. has an opportunity to encourage the development and availability of high-quality tests. Recently, the FDA has mentioned a forthcoming pilot program that would establish “minimum performance criteria” for tests used to enroll patients into clinical trials and could eliminate the need to develop companion diagnostics. The FDA has not provided a description of the pilot program for public review and comment, but it is possible that current FDA review requirements for tests used to make important decisions on therapy selection may be substantially lowered.

We already know that the quality and the level of validation of tests used to select therapy for patients can vary dramatically. [2]

In our development experience, we have observed that less-validated testing has incorrectly identified patients as positive or negative for biomarkers, meaning that patients may have lost out on the opportunity to try a potentially life-saving therapy or been exposed to a therapy with no benefit. We have also seen that our testing is able to “overturn” incorrect diagnoses, which has dramatic impacts on the treatment plans for patients. One recent example is of a patient who was initially thought to have lung cancer, but through our testing was found to have metastatic skin cancer treatable with an FDA-approved targeted therapy.

Using “minimum performance criteria” to replace the well-proven performance of FDA-approved companion diagnostics risks patient safety and outcomes and could fundamentally establish a floor verses a ceiling for quality diagnostic testing.

At the same time, it is encouraging to see payers recognize the value of an approved companion diagnostic as a marker for high-quality diagnostic testing.

The Centers for Medicare and Medicaid Services (CMS) has long acknowledged the benefit to patients of high-quality companion diagnostics, like FoundationOne CDx and FoundationOne®Liquid CDx, and covers them for Medicare beneficiaries with advanced cancer. Recently, UnitedHealthcare decided to provide commercial coverage for FoundationOne CDx and FoundationOne Liquid CDx in multiple cancer types, which hinges in part on the substantial analytical and clinical validation that these tests undergo by virtue of being FDA-approved companion diagnostics.[3]

In its medical policy, UnitedHealthcare notes that tests not FDA approved as a companion diagnostic are “unproven and not medically necessary.” It is difficult to understand how any test meeting "minimum performance criteria" would clear this bar, but more importantly how the FDA would ensure critical test quality when guiding therapy selection for patients.

How can policymakers uphold high-quality standards while enabling innovation?

Last year, the U.S. Congress considered legislation known as the Verifying Accurate Leading-edge IVCT Development (VALID) Act of 2022 (S.4348). The VALID Act would subject all diagnostic tests to the same risk-based regulatory framework. While unsuccessful, we continue to support the VALID Act because it would require the clinical validation of high-risk tests, including companion diagnostics. The legacy of regulatory reform should be patients’ improved access to well-validated tests that transform the future of cancer care.

In addition to Congressional legislation, the FDA could use its authority to maintain high standards for companion diagnostics, but reduce critical barriers faced by developers. For example, challenges arise in the development of companion diagnostics for rare biomarkers or indications, and the FDA could exert flexibility in the level of validation or types of data required of companion diagnostic developers to gain approval for their tests. Additionally, companion diagnostic test developers have often faced lengthy FDA reviews to make even simple, low-risk changes to their tests. We have been encouraged by the FDA’s efforts to implement more streamlined reviews of modifications, including leveraging pre-determined change protocols. These types of policy changes promote more efficient, less burdensome review and approval of companion diagnostics and help ensure that patients have access to high-quality tests when they need them.

Finally, all payers play an important role in ensuring access to high-quality tests and eliminating disparities in coverage. Everyone loses—no one more so than the patient—when a health plan cannot differentiate among tests, guaranteeing coverage for lower quality tests. Health plans and state Medicaid programs should use an evidence-based approach for coverage decisions that values access to high-quality tests that have met rigorous standards.

As the science of cancer and the technologies used to treat the disease becomes more complex, we all share an obligation to prioritize quality, giving patients the best chance at finding answers and unlocking solutions.


[1] Muthusamy, B., et al., Quantifying the Value of Multigene Testing in Resected Early Stage Lung Adenocarcinoma, Journal of Thoracic Oncology. December 6, 2022.


[2] Pfeifer, J.D., et al., Reference Samples to Compare Next-Generation Sequencing Test Performance for Oncology Therapeutics and Diagnostics, American Journal of Clinical Pathology, Volume 157, Issue 4, April 2022, Pages 628–638,


[3] Foundation Medicine, February 9, 2023, UnitedHealthcare Provides Commercial Coverage for FoundationOne®CDx and FoundationOne®Liquid CDx in Multiple Companion Diagnostic Indications, [Presss release],



May 22, 2023 Brian Alexander, MD Chief Executive Officer, Foundation Medicine

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