Grail’s multi-cancer early detection test in prostate cancer shows efficacy

Grail announced that detailed findings of the performance of its Galleri multi-cancer early detection test in prostate cancer were published in JCO Precision Oncology. The data support the clinical performance of the Galleri test to preferentially screen for aggressive, clinically significant prostate cancer as compared to slow-growing cases in the Circulating Cell-free Genome Atlas and PATHFINDER studies. The published data is from an analysis of 420 prostate cancer patients identified in the independent clinical validation portion of the multi-center, case-control observational study Circulating Cell-free Genome Atlas study and 18 cases from the prospective intended-use PATHFINDER study. Results from this analysis showed that of the prostate cancers that were detected by the MCED test, most were clinically significant – 93% were intermediate or high grade and 67% were stage III or IV -. For detected prostate cancers, the cancer signal of origin prediction accuracy was greater than 90%. Test sensitivity of prostate cancer for all stages was 11.2% in substudy CCGA-3. The MCED test detected no low-grade cancers, 1.9% of intermediate-grade cancers, and only 4.2% of stage I and II cancers across both studies combined. This analysis demonstrates the MCED test preferentially detects high-grade, clinically significant prostate cancer, important because an MCED test should not exacerbate overdiagnosis of indolent cancers.