The US Food and Drug Administration (FDA) has proposed moving a group of cancer treatment-selection tests into a less demanding review category, while keeping premarket review in place. The proposal, published in the Federal Register on 12 November 2026, covers immunohistochemistry (IHC) test systems used with an approved cancer medicine. These tests detect protein expression in patient samples and help clinicians decide which patients may benefit from a particular treatment.
What the Proposal Covers
The proposal would reclassify the covered devices from class III, which requires premarket approval, to class II with special controls. Manufacturers would instead seek clearance through the agency's 510(k) premarket notification pathway before marketing a device. The proposal does not exempt the tests from FDA review. The covered group spans 12 device product codes and includes both companion diagnostics essential to the safe and effective use of an approved medicine and other tests that provide information about a medicine's benefits or risks. The FDA is also proposing a new classification regulation for these tests, along with minor revisions to the existing regulation for immunohistochemistry reagents and kits.
The proposal is specific to IHC-based systems used with approved oncology therapies. It is not a blanket change for every cancer diagnostic or every kind of companion test.
Why the FDA Says the Change Is Safe
The FDA cited its experience with the technology, data from earlier premarket approvals, published research and postmarket safety information. The agency reviewed data from 14 original premarket approvals available for use under federal law. It concluded that special controls, together with general controls, would give reasonable assurance of safety and effectiveness for these tests.
The risks the agency identified are false-positive and false-negative results, test-system failures and misinterpretation, all of which can affect treatment choices. The proposed special controls are built around those risks. They include clinical and analytical performance testing, risk-mitigation procedures, user-training requirements and labelling. Clinical evidence would need to show acceptable performance using data representative of the intended patient population, and analytical testing would address precision, sensitivity, specificity and specimen stability. Labelling would explain that qualified or trained readers should interpret results alongside other laboratory or pathology findings, clinical information and proper controls.
Tests already approved under premarket approval could continue to be marketed under that approval if the order is finalised. Manufacturers would need a 510(k) for changes that could significantly affect a device's safety or effectiveness, or for a major change in its intended use.
What Happens Next
The change is not final. Comments on the proposal are due by 11 January 2027, and the FDA must review them before issuing a final order. The proposal says a final order would take effect 30 days after it is published, but no date for a final order has been set.
The FDA said a 510(k) submission is generally less burdensome and more cost-effective than a premarket approval application, and typically has a shorter review timeline. The agency expects reclassification could encourage more manufacturers to develop these tests and improve patient access. Those are the agency's expectations, not measured savings or guaranteed reductions in waiting times, and the proposal does not set a price reduction for laboratories, insurers or patients.
Part of a Wider Reclassification Effort
The proposal is the latest step in a wider FDA effort to move oncology companion diagnostics out of the premarket approval pathway. A final order reclassifying in situ hybridisation test systems used with approved cancer medicines took effect in September 2026, and a proposal covering nucleic-acid-based oncology companion diagnostics was published in November 2025. The IHC proposal follows the same pattern, using data from earlier approvals to set special controls for a group of tests the agency now considers well characterised.
Why This Matters for Healthcare Organizations
For hospitals, cancer centres and pathology laboratories, the practical effect would come later, if the order is finalised. A 510(k) pathway could bring more IHC tests to market sooner and give laboratories more options when choosing a test for a particular medicine. That matters for oncology practices, where treatment decisions often depend on a test result, and where a delayed or unavailable test can delay treatment.
The safeguards matter as much as the pathway. A wrong result can send a patient toward a treatment that will not help, or away from one that would. Laboratories should watch the final order and the special controls, since training and labelling requirements will shape how their staff use these tests. Recent approvals show how closely tests and treatments now travel together. The FDA's approval of pimicotinib for symptomatic tenosynovial giant cell tumor and its accelerated approval of Rybrevant Faspro for head and neck cancer both rest on identifying the right patients for the right drug, which is the job these tests do.
If your clinic fields patient questions about new cancer tests or treatments, a patient portal that handles intake, scheduling and messages gives patients a straightforward way to ask, and our look at how an AI medical receptionist handles after-hours calls shows how clinics manage the first contact.
Analysis: A Narrower Pathway, Not a Lower Bar
This proposal changes how these tests are reviewed, not whether they are reviewed. The FDA is saying that after years of premarket approvals, it knows enough about these tests to set clear controls and let new versions reach the market through the 510(k) route. That is a judgement about the technology, not a judgement that the risks have gone away.
Two things are worth watching. First, the comments, since test makers, laboratories and patient groups may push back on the details of the special controls. Second, the final order itself, since the proposal is only a starting point and the FDA can change course after the comment period. Until then, nothing changes for laboratories using these tests today.
Sources and References
- U.S. Food and Drug Administration, Hematology and Pathology Devices; Reclassification of Immunohistochemistry Test Systems for Use With a Corresponding Approved Oncology Therapeutic Product, proposed order, Federal Register, 12 November 2026: https://www.federalregister.gov/documents/2026/11/12/2026-23005/hematology-and-pathology-devices-reclassification-of-immunohistochemistry-test-systems-for-use-with
- JBizNews, FDA Proposes Less Burdensome Review Path for Cancer Treatment-Selection Tests, 12 November 2026: https://jbiznews.com/fda-proposes-less-burdensome-review-path-for-cancer-treatment-selection-tests/
Reporting based on the sources above, accessed 12 November 2026. The Federal Register proposed order was read directly, and the JBizNews report was read directly and cross-checked against it. Med Clinic X did not conduct original reporting or interviews for this article. Corrections: contact us via https://medclinicx.com/contact