TEST:

Guardant360® CDx

P1, N=22, Active, not recruiting, National Cancer Institute (NCI) | N=85 --> 22 | Trial completion date: Jun 2026 --> Nov 2026 | Trial primary completion date: Jun 2026 --> Nov 2025

Intrapatient ctDNA variability over time in EGFR-mutant advanced NSCLC includes changes that may confound interpretation of treatment activity, depending on the magnitude of change used to indicate molecular response. These findings demonstrate that evaluation of on-treatment changes must account for potential background variability, including technical variability because of factors such as cfDNA input level and tumor-related VAF, and that baseline samples should be obtained as close as possible to treatment initiation to minimize the impact of background variability.

Baseline low ctDNA levels predict response to targeted therapy, potentially suggesting shared mechanisms between high ctDNA release and resistance to therapy. Both baseline ctDNA levels and on-treatment dynamics are a promising surrogate endpoint for drug development, with clearance of ctDNA being a robust cross-therapy surrogate for outcome.

P1/2, N=58, Active, not recruiting, National Cancer Institute (NCI) | Recruiting --> Active, not recruiting

In a Mayo Clinic subset, ten patients received olaparib based on treatment-emergent alterations, but none achieved a prostate-specific antigen (PSA) response. Two patients who transitioned from low to high TMB received pembrolizumab, both with progressive disease as best response. In a large real-world cohort, serial ctDNA testing frequently identified new alterations that were not detected at baseline and are potentially actionable therapeutic targets, highlighting the value of serial genomic profiling for capturing clonal dynamics. Additional research is needed to better establish a framework for retesting and to clarify how these results should influence subsequent treatment decisions.

Median time from diagnosis of stage IV disease to progression was 25.3 months and median overall survival was 4.9 years. This study adds more insight to the limited existing data regarding rare mCRC cases with concomitant BRAF and RAS family mutations and exposes the need for future research on larger populations of this rare subset of patients.

A circulating tumor DNA analysis effectively captured genomic evolution at recurrence, identifying clinically relevant alterations not found in primary tumor tissue. These findings support the integration of a liquid biopsy into clinical practice to guide treatment for recurrent gastric or gastroesophageal junction cancer.

Our prediction system effectively stratified patients by the likelihood of KRAS mutation detection, offering a practical tool for selecting candidates for liquid biopsy. These findings underscore the importance of personalized approaches in unresectable PC management and suggest that patients without these key clinical factors may not benefit from ctDNA testing. Future studies should validate this model in larger cohorts.

Baseline CTC enumeration provides significant prognostic information in HR+/HER2- MBC. StageIV aggressive patients derive greater benefit from F+P or F+P+A over F alone, independent of clinical or ctDNA features. This highlights the potential of to guide treatment decision-making.

P=N/A, N=470, Recruiting, Guardant Health, Inc. | Trial completion date: Aug 2029 --> Dec 2030 | Trial primary completion date: Aug 2029 --> Dec 2030

Patients without altered ESR1, PIK3CA, CCND1, or FGFR1 at baseline had better rwPFS than patients with altered genes. Genotyping analysis of ctDNA over time highlights the emergence of mutations in estrogen receptor and cell cycle pathways under selective therapeutic pressure and could guide monitoring and therapeutic sequencing for patients with HR+/HER2- ABC.

P2, N=30, Recruiting, Massachusetts General Hospital | Trial completion date: Dec 2025 --> Mar 2027 | Trial primary completion date: Jul 2025 --> Aug 2026