A roadmap to treatment written in blood
In the ongoing effort to make cancer treatment as precise as the disease is complex, two diagnostics companies have deepened their collaboration to bring a new genetic test closer to the clinic. Biodesix and Bio-Rad Laboratories are expanding a partnership already proven in lung cancer to now detect ESR1 mutations in advanced breast cancer patients — mutations that increasingly determine which therapies may help and which may not. The work reflects a broader shift in oncology: from treating cancer as a category to treating it as a constellation of individual molecular signals, each one a potential guide toward more effective care.
- A new class of oral breast cancer drugs is gaining ground, but their benefit depends on identifying which patients carry specific ESR1 mutations — and the diagnostic tools to do so reliably are still catching up.
- Biodesix and Bio-Rad are racing to close that gap, leveraging their established ddPCR technology to build and validate a highly sensitive assay capable of detecting cancer DNA fragments circulating in a patient's blood.
- The partnership assigns Biodesix the full operational burden — development, clinical validation, regulatory submissions, and kit distribution — while Bio-Rad contributes its QX600 platform and years of shared expertise.
- Reimbursement from CMS remains a critical hurdle; without it, even a validated, accurate test risks remaining out of reach for many of the patients who need it most.
- The companies are set to present their roadmap at the AMP conference in Boston in November, signaling that commercial momentum is building alongside the science.
Two diagnostics companies have expanded their partnership to develop a test that could reshape how doctors monitor a specific form of advanced breast cancer. Biodesix and Bio-Rad Laboratories are building on years of collaboration in lung cancer diagnostics to now target ESR1 mutations — genetic alterations that have become central to treatment decisions in hormone receptor-positive, HER2-negative breast cancer.
The technology at the heart of this effort is Droplet Digital PCR, or ddPCR, which Bio-Rad has refined through its existing work with Biodesix. The new assays will run on Bio-Rad's QX600 platform, scanning circulating tumor DNA in a patient's bloodstream for ESR1 mutations with high sensitivity. The urgency behind the work is clinical: a new generation of oral drugs known as selective estrogen receptor degraders has shown real benefit for patients whose tumors carry these mutations, making fast and accurate detection increasingly essential.
Biodesix will lead the effort end-to-end — developing the assay, conducting clinical validation, managing regulatory submissions, and distributing specimen collection kits. Testing will be offered through its CLIA-CAP accredited laboratory, serving both pharmaceutical developers and clinicians monitoring patient response. The company is also pursuing CMS reimbursement, a step that could determine how broadly the test reaches patients in practice.
Leaders from both companies described the expansion as a natural progression, grounded in a track record of working together effectively. Their research and commercial plans are set to be presented at the AMP conference in Boston in mid-November — a public signal that the partnership is moving from the lab toward the clinic.
Two diagnostics companies have joined forces to build a new test that could change how doctors monitor a specific type of advanced breast cancer. Biodesix, a diagnostics firm, and Bio-Rad Laboratories have expanded their existing partnership to develop and validate assays that detect ESR1 mutations—genetic changes that have emerged as critical markers in hormone receptor-positive, HER2-negative breast cancer.
The work centers on a technology called Droplet Digital PCR, or ddPCR, which Bio-Rad has developed and refined over years of collaboration with Biodesix on lung cancer diagnostics. The new assays will use Bio-Rad's QX600 platform to hunt for ESR1 mutations in circulating tumor DNA—fragments of cancer DNA that float in a patient's bloodstream. This kind of detection matters because ESR1 mutations have become increasingly important in guiding treatment decisions for advanced breast cancer patients.
Why the urgency? A new class of drugs called oral selective estrogen receptor degraders, or SERDs, has shown clinical benefit for patients whose tumors carry ESR1 mutations. As these therapies gain traction, the demand for fast, accurate tests to identify which patients might benefit has grown sharply. The ddPLEX ESR1 Mutation Detection Assay—the first test to be validated under this expanded agreement—is designed to detect these mutations with high sensitivity and to quantify how many are present in a patient's sample.
Biodesix will take the lead on the heavy lifting: developing the assay, running the clinical validation studies, handling regulatory submissions, and eventually manufacturing and distributing the specimen collection kits. Once regulators clear the test, Biodesix plans to offer ESR1 testing through its own CLIA-CAP accredited laboratory, serving both pharmaceutical companies developing new breast cancer drugs and clinical customers who need to monitor their patients' treatment response. The company is also pursuing reimbursement from the Centers for Medicare & Medicaid Services, a step that could make the test accessible to more patients.
Scott Hutton, Biodesix's CEO, framed the partnership as a response to real clinical need. He emphasized that the combined expertise of both companies in mutation detection positions them to deliver tests that are both rapid and precise, opening pathways toward more personalized cancer care. Steve Kulisch, who oversees product management for Bio-Rad's Life Science Group, noted that the companies have already proven they can work together effectively—their lung cancer diagnostics portfolio, built on the same ddPCR technology, has been in use for years. Expanding into breast cancer represents a natural next step.
The two companies plan to discuss their research roadmaps and commercial strategy at the AMP conference in Boston in mid-November, with separate corporate workshops scheduled for November 12. For patients with advanced breast cancer, the validation of this test could mean faster answers about which drugs might work best—and for the companies involved, it represents another step in translating molecular biology into clinical tools that actually reach patients.
Citas Notables
The combined capabilities in mutation detection can address clinical needs with speed and precision, opening doors to personalized, data-driven medicine.— Scott Hutton, CEO, Biodesix
Validation of the ESR1 kits will further expand combined capabilities in clinical diagnostics, increasing access to sensitive biomarker detection for advanced breast cancer.— Steve Kulisch, VP Product Management, Life Science Group, Bio-Rad Laboratories
La Conversación del Hearth Otra perspectiva de la historia
Why does detecting ESR1 mutations matter so much right now in breast cancer care?
Because there's a new generation of drugs—SERDs—that work specifically for patients whose tumors have these mutations. Without a test to find them, doctors can't know who should get these drugs. The mutations are becoming a roadmap to treatment.
And these mutations show up in blood, not just in tumor tissue?
Exactly. That's what makes this approach powerful. Circulating tumor DNA in the bloodstream gives doctors a window into what's happening in the cancer without needing a biopsy. It's less invasive and can be done repeatedly to track how a patient is responding.
Why does Biodesix need Bio-Rad's technology specifically?
Bio-Rad's ddPCR platform is exceptionally sensitive—it can detect rare mutations even when they're present in very small amounts. For cancer monitoring, that sensitivity matters. You want to catch changes early, before they become obvious clinically.
What's the business angle here? Why would Biodesix want to offer this as a service?
They're positioning themselves as a clinical diagnostics company. If they can validate the test, get it through regulators, and secure insurance reimbursement, they have a revenue stream. But it's also about being useful—there's real demand from oncologists who need this information.
What happens if CMS won't reimburse it?
Then the test exists, but fewer patients can access it. Insurance coverage is often the difference between a test that reaches thousands of patients and one that sits on a shelf. That's why they're pursuing it proactively.