The purpose of SIBYL is to generate clinical validity data for the ability of a future version of Guardant360 developed by Guardant Health to measure response to systemic therapy in patients with unresectable advanced solid tumors. It is necessary to collect clinical data points and treatment outcomes in order to demonstrate clinical validity for longitudinal monitoring with ctDNA and correlation of ctDNA dynamics with therapeutic response, as evaluated by standard methods, including RECIST 1.1 and CT scan measurements.

Inclusion Criteria

Each participant must satisfy all the following criteria to be enrolled in the study:

1. Age ≥18 years old

2. Are treated with systemic therapy and/or oral SOC regimen at the site of enrollment during entirety of study

3. Patient is either treatment naive and has not yet commenced first line SOC therapy OR patient has completed first line SOC therapy and will commence second line of SOC therapy

4. Able to understand, and capable of providing written consent to participate in the study

5. Are willing to have de-identified clinical data shared with investigators at regular intervals outlined in the study protocol and informed consent

6. Are willing to provide blood samples at enrollment and at subsequent clinical visits

7. Have a histologically confirmed Index cancer that qualifies for inclusion, defined as:

   • Cohort 1: Unresectable Stage III/IV NSCLC (~125)
   • Cohort 2: Stage IV Colorectal (~125)
   • Cohort 3: Unresectable Stage III/IV Breast - HR+ HER2- (~55)
   • Cohort 4: Unresectable Stage III/IV Breast - HR- HER2+ (~55)
   • Cohort 5: Unresectable Stage III/IV Breast - HR+ HER2+ (~55)
   • Cohort 6: Unresectable Stage III/IV Breast - Triple Negative (~55) Determination of stage for eligibility assessment and enrollment should be based on clinical or pathologic stage.

Exclusion Criteria

Any potential participant who meets and of the following criteria at the time of initial enrollment will be excluded from participating in the study:

1. History of prior solid malignancy or hematological malignancy within five years of enrollment
2. Life expectancy ≤12 weeks
3. Unable to collect a baseline blood sample during a SOC venipuncture, and prior to starting SOC regimen
4. Is participating in a clinical trial or another observational study that is evaluating the performance of another genomic test for detecting/predicting clinical response/progression

The primary study population will include participants with Non-small cell lung cancer (stage III-IV), Colorectal adenocarcinoma (stage III-IV), and Breast Cancer (stage III-IV), as per inclusion/exclusion criteria. Approximately 470 total patients will be enrolled into the study.