Study Rationale:
There is some evidence that identifying non-responders early in neoadjuvant treatment and offering alternative agents (response-guided therapy) increased pathological complete response (pCR) rates and/or survival resulting in improved care and incremental cost effectiveness.
Differentiating non-responders to chemotherapy from responders with reliable guidance tools early during therapy is crucial to the success of response-guided therapy.
The current study aims to provide validation results of RDA as a tumor response assessment tool that uses tumor core biopsies starting from 35 +/- 4 days after the initiation of neoadjuvant chemotherapy.
Study Objectives and Endpoints:
The primary objective of the study is to determine the 2 RDI cut-offs to have a diagnostic test optimized in terms of both negative and positive predictive values NPV and PPV (in a training set of patients i.e. phase 1 of the study) for predicting nopCR/pCR and to establish the performance characteristics for the first cut-off (test result "zone 1") in terms of NPV as primary endpoint (in a validation set i.e. phase 2).
The secondary objective is to assess the test's NPV in the different cancer subtypes and the test's PPV in Her2+ patients; also to assess and compare pCR prevalence, residual cancer burden (RCB class at surgery) and DFS (secondary endpoints) in zones 1-3 for all patients and each cancer subtype.
Patient Population:
The study aims to enroll approximately 801 patients in centers in the US, Canada, Italy, Germany, Spain and France and Poland.
The population consists of patients diagnosed with invasive breast cancer and scheduled to receive neoadjuvant chemotherapy as part of standard of care treatment. Throughout the study, patients will receive standard of care neoadjuvant chemotherapy treatments including taxanes, anthracyclines or other targeted drugs and drug combinations as prescribed based on the investigators' / clinicians' choice. Adjuvant therapies (e.g. radiotherapy, hormonal treatment … etc.) may be prescribed to patients according to standard of care and independently of the RDI score results.
RDA is presently in an experimental stage and clinicians will not receive or use the RDA results in this study.
Biopsy Collection:
* 1st core needle biopsy for RDA (2 specimens): Time Point: 35 +/- days after initiation of neoadjuvant chemotherapy;
* 2nd core needle biopsy for RDA (2 specimens): Time Point: if therapy is changed (as part of SoC), a second biopsy \~2-3 weeks after initiation of new drugs; Timing by type of drug schedule 3-weekly: at 16 days +/- 2 days, Bi-weekly: at day of 2nd dose preferably before drug admin., Weekly: at day of 4th dose preferably before drug admin. If Therapy is not changed (as part of SoC), a second biopsy is taken at 55 +/- 5 days after the first initiation of neoadjuvant therapy.
Statistical Plan:
The study consists of a training set / phase 1 (80 fully evaluable patients) to determine response zone cut-offs using pCR outcomes and RDA's predictive values, and a validation set / phase 2 (454 fully evaluable patients) to validate the performance characteristics of the RDA test. The study aims to enroll 801 patients in order to achieve an accrual of 534 fully evaluable patients (phase 1 and 2) which is the number required to adequately statistically power the trial. Recruitment per subgroup of cancer subtypes will be closed when the target number of fully evaluable patients per subgroup is reached for both phase 1 and 2. Combined statistical analysis and various subgroup analyses will be performed for the primary and secondary objectives.
Duration and Follow-up:
There will be an active patient accrual until last patient is accrued (to achieve the required fully evaluable patient numbers) in addition to 60 months of patient follow-up.
