Galleri PMA Panel Vote: Favorable Benefit-Risk Signal Undermined by Split Effectiveness Verdict

FDA Advisory Committee Recommends Approval for GRAIL's Galleri Test

GRAIL, Inc. announced a favorable vote from the Molecular and Clinical Genetics Devices Panel of the Medical Devices Advisory Committee of the U.S. Food and Drug Administration (FDA) for the Premarket Approval (PMA) application of its Galleri® multi-cancer early detection test. The Committee considered Galleri’s safety, effectiveness, and overall benefit-risk profile for screening adults aged 50 years and older. The panel voted seven to two with one abstention that the benefits outweigh the risks, unanimously in support of safety, and six to four in support of effectiveness. This vote reinforces the strength of Galleri’s clinical evidence as GRAIL works with the FDA to complete its review.

• The FDA's Molecular and Clinical Genetics Devices Panel conducted three separate votes on the Galleri test. The Committee voted seven to two with one abstention that the benefits of Galleri outweigh its risks, unanimously in support of Galleri’s safety, and six to four in support of Galleri’s effectiveness for screening adults aged 50 years and older.
• The Galleri test is designed to detect cancer-specific methylation patterns before symptoms appear, including for cancers without recommended screening. It also predicts the cancer signal origin with high accuracy to guide diagnostic evaluation and is intended to be used in addition to, not as a replacement for, guideline-recommended screenings.
• Galleri is supported by large interventional and randomized controlled studies, including PATHFINDER 2 and the NHS-Galleri trial. Clinical studies have shown Galleri detected approximately four to seven times more cancers compared to standard of care alone, with most found at earlier stages, while maintaining a low false-positive rate and high Cancer Signal Origin prediction accuracy.
• GRAIL submitted its PMA application for Galleri to the FDA on January 29, 2026, following its designation as a Breakthrough Device in 2018. The FDA is expected to make a final decision on the Galleri PMA in the coming months, taking the advisory committee's recommendations into consideration.

Addressing Critical Unmet Needs in Multi-Cancer Detection

Recent oncology research has increasingly focused on identifying and addressing gaps in treatment efficacy, patient selection, and equitable access across multiple tumor types. The following areas represent the most prominent unmet needs and high-priority populations emerging from the literature.

• Heavily pretreated and refractory hematologic malignancies: Patients with triple-class refractory and penta-drug refractory multiple myeloma have historically faced poor outcomes due to a dearth of effective treatment options. CAR T-cell and bispecific antibody therapies have produced unprecedented response rates in these populations, though optimal sequencing, supportive care, and equitable access across minoritized racial, ethnic, and socioeconomic populations remain unresolved challenges.

• Advanced solid tumors with limited immunotherapy benefit: The first-in-human study of EMB-02, a bispecific antibody targeting PD-1 and LAG-3, enrolled patients with advanced solid tumors, including those previously treated with checkpoint inhibitors (CPI). The clinical benefit rate at 24 weeks was 33.3% in CPI-naïve patients versus 15% in CPI-treated patients, highlighting the persistent unmet need in checkpoint inhibitor–experienced populations. No clear relationship was observed between efficacy and PD-L1, LAG-3, or MHC II expression, underscoring the need for improved predictive biomarkers.

• Advanced urothelial carcinoma after platinum and ICI failure: A systematic review and meta-analysis of enfortumab vedotin (EV) in advanced urothelial carcinoma identified a cumulative objective response rate of 48%, yet patients with poor Eastern Cooperative Oncology Group performance status, high Bellmunt risk score, or non-urothelial carcinoma histology subtypes demonstrated significantly worse outcomes. PD-L1 expression positivity and FGFR3 alterations were not associated with outcomes, leaving optimal patient selection an active area of need.

• Endocrine-resistant and high-risk ER-positive breast cancer subtypes: ERpHER2n Basal-like breast cancer, as defined by PAM50 gene expression subtyping, represents a clinically high-risk subgroup associated with worse prognosis than Luminal A/Luminal B subtypes, especially when treated only with endocrine therapy. Its molecular resemblance to triple-negative breast cancer — including high immune infiltration and mutational signatures associated with homologous recombination deficiency — highlights potential therapeutic opportunities with immune checkpoint inhibitors and DNA repair-targeting treatments such as platinum or PARP inhibitors.

• Treatment-refractory pancreatic and biliary tract cancers: A Phase 1 study of palbociclib combined with cisplatin or carboplatin in advanced pancreatic cancer reported a median progression-free survival of 1.9 months (95% CI: 1.7, 2.4) and overall survival of 3.7 months (95% CI: 2.7, 5.7) in pancreatic ductal adenocarcinoma, with no objective responses observed. Approximately half of pancreatic ductal adenocarcinoma patients achieved disease stabilization, reflecting the profound unmet need in this population and the need to better exploit CDK abnormalities.

• Global access disparities for immune checkpoint inhibitor therapy: High costs of standard-dose immune checkpoint inhibitors limit access for much of the global population. A systematic review of low-dose ICI regimens — including pembrolizumab <2 mg/kg, nivolumab <2.15 mg/kg, nivolumab 20 mg or 100 mg once every 3 weeks, and pembrolizumab 100 mg once every 3 weeks — demonstrated comparable overall survival to standard dosing in non-small cell lung cancer and renal cell carcinoma, suggesting weight-based or reduced flat-dose regimens as a potentially viable alternative in low- and middle-income countries.

Key Clinical Data Supporting Galleri's Efficacy and Safety

Several pivotal trials across oncology indications have evaluated novel therapeutic strategies, spanning targeted therapies, immunotherapy, and biosimilars. The trials below represent a cross-section of study designs and endpoints used to characterize efficacy and safety in distinct cancer populations.

Integrating Galleri into Existing Multi-Cancer Diagnostic Practices

Multi-cancer identification in clinical practice draws on a layered diagnostic framework that combines morphological assessment, protein biomarkers, molecular profiling, and genomic characterization. Each modality contributes distinct information, and their integration is increasingly central to guiding site-specific and personalized therapy.

• Immunohistochemistry (IHC) and cytokeratin profiling: IHC-based assessment, including cytokeratin expression patterns, enables identification of tissue of origin by exploiting the fact that epithelial cells acquire specific keratin profiles during differentiation that remain stable during carcinogenesis. In cancer of unknown primary (CUP), IHC staining led to the prediction of a single tissue of origin in 10.8–51% of cases.

• CUP classifiers: Molecular classifiers identified the primary site in 61–89% of CUP cases and were concordant with IHC in 57.1–100%. These tools were expected to gradually replace the classical multistep approach in identifying the culprit tumors to guide site-specific therapy, though they are less widely available and have not been validated in randomized control trials.

• Serum tumor markers — CA-125, CA 15-3, CA 19-9, and CEA: These protein biomarkers are used in monitoring malignancy across multiple cancer types. CA 15-3 is independent of gestation and is considered a reliable tumor marker in monitoring malignancy in pregnant patients, while CA-125, CEA, and CA 19-9 levels increase during the third trimester of pregnancy, though within the normal range.

• Microsatellite instability (MSI) and tumor mutational burden (TMB): MSI and TMB are established biomarkers for immunotherapy selection across solid tumors. A 1021-gene next-generation sequencing (NGS) panel detected on-label treatment biomarkers in 12.57% of patients, increasing to 20.15% when immunotherapy markers — including MSI and TMB — were included, across over 1,300 solid tumor samples from diverse histologies.

• Circulating tumor DNA (ctDNA) via liquid biopsy: ctDNA detected in plasma demonstrated actionable variants in 70% of evaluable cases using the 1021-gene NGS panel, supporting its role as a complementary diagnostic tool alongside tissue-based profiling. In colorectal cancer specifically, ctDNA is recognized as a therapeutic biomarker informing personalized treatment decisions.

• Targeted protein biomarkers including HER2, PSA, CEA, CA-125, and CYFRA21-1: These tumor antigens serve as diagnostic and monitoring targets across cancer types. Electrochemical aptasensor platforms based on core-shell MOF nanostructures have been developed for their ultrasensitive detection, with applications spanning prostate, breast, ovarian, and lung cancers, among others.

• YKL-40 as a prognostic serum biomarker: Serum YKL-40 has been confirmed as a biomarker of prognosis in 13 different cancer types encompassing more than 2,500 patients, with highest levels observed in patients with metastatic cancer with the shortest recurrence-free interval and shortest overall survival. It provides independent prognostic information compared with clinical characteristics and biomarkers such as HER2, carcinoembryonic antigen, CA-125, prostate-specific antigen, and lactate dehydrogenase.

Galleri's Favorable FDA Vote: A New Era for Multi-Cancer Screening

The recent favorable vote from the FDA advisory committee for GRAIL's Galleri multi-cancer early detection (MCED) test represents a significant milestone, signaling a potential paradigm shift in how we approach cancer screening. This endorsement, particularly on the test's safety and overall benefit-risk profile for adults aged 50 and older, moves the field closer to a future where a single blood test could screen for dozens of cancers simultaneously.

This development holds substantial strategic implications. For Galleri, it de-risks the regulatory pathway, potentially paving the way for market leadership in the nascent MCED space. Such an approval would not only accelerate adoption among the target demographic but also set a crucial precedent for other MCED developers. Furthermore, the design of ongoing large-scale trials, like the NHS-Galleri RCT, which uniquely focuses on late-stage cancer incidence as a primary outcome, will undoubtedly influence future clinical evidence generation strategies across the industry.

However, the journey to widespread MCED adoption is not without its complexities and risks. While simulation models project a meaningful shift to earlier cancer stages and a reduction in mortality, current data indicate variable sensitivity, particularly for detecting early-stage cancers. This means that while the test is highly specific, its ability to catch cancers at their most treatable stages needs careful consideration. Moreover, the observed positive predictive value (PPV) of 44% in real-world settings highlights the potential for false positives, which could lead to unnecessary diagnostic procedures, patient anxiety, and increased healthcare system burden. The absence of completed randomized controlled trials demonstrating a direct reduction in cancer mortality remains a critical gap that future research must address to fully validate the long-term clinical utility and cost-effectiveness of MCED tests.