Abstract OT2-03-01: RNA disruption assay (RDA) - Breast cancer response evaluation for individualized therapy (brevity/brevity-02)
Authors: Trudeau Maureen , Tio Joke , Ademuyiwa Foluso , Petit Thierry , Hennessy Bryan , Cazzaniga Marina , Generali Daniele 
Published: March 2022

Background & Rationale Identifying non-responders to chemotherapy with reliable predictive tests is crucial to response-guided neoadjuvant therapy. BREVITY aims to support RDA as a response assessment tool in breast cancer.RDA is based on RNA disruption, a qualitative and quantitative alteration of ribosomal RNA that correlates with chemotherapy response. RDA stratifies patients into 3 zones: non-response zone 1, partial-response zone 2 and response zone 3. Survival data in MA.22 trial showed significantly superior 5-year DFS KM-curves for zone 3 patients compared to zones 1 & 2. MA.22 and other studies indicated a potentially valuable clinical utility to be pursued. Trial Design. Study type: Prospective 2-phase interventional study. Samples: 2 core needle biopsy specimens taken at 2 time points during chemotherapy. 1

Follow-up: 60 months from date of study enrolment. Incl. Criteria. •Women 18+ years old and able to provide informed consent. •Newly diagnosed clinical stage I, II or III breast cancer with complete surgical excision after neoadjuvant therapy as treatment goal. •Confirmation of invasive breast cancer of any subtype or grade, tumor size &gt; 1cm. •Scheduled for neoadjuvant chemotherapy +/- antibodies and +/- other drugs according to SoC. •Willing to have research core needle biopsies at 2 timepoints during neoadjuvant treatment. Excl. Criteria. •Prior local or systemic therapy for current breast cancer. •Participation in another interventional clinical trial with experimental drugs during neoadjuvant therapy. •Stage IV breast cancer. •Bilateral, multifocal or multicentric breast cancer. •Prior malignant disease except curatively treated basalioma of the skin or pTis of the cervix uteri. •Pregnancy or breast feeding. Trial Objectives & Endpoints

Statistical Methods. Phase 1: training set will be used to estimate and visualize operating characteristics as functions of RDI. These include NPV, PPV, sensitivity, specificity, and related concepts. Suitable cut-offs will be determined that optimize NPV of zone 1 and PPV of zone 3. Phase 1 powered to estimate 25th RDI percentile as candidate for cut-off c1 with 9.5% precision E. Phase 2: analysis by interval-estimation of performance characteristics on an independent validation set, given cut-offs selected in phase 1. Primary target of validation is NPV of zone 1 that corresponds to RDA’s main clinical utility. PPV of zone 3 to be established for selected subgroups. Sample size for validation chosen to yield 95% CI estimate for NPV with 5.25% precision. Present and Target Accrual. Present AccrualTarget Accrual(must be fully evaluable). Phase 1 (Training set):71 (target 80). Phase 2 (Validation set):454 Other Contacts. Sponsor: Rna Diagnostics Inc

Biopsy Collection Time Points for RDABiopsy(2 specimens)1st core biopsy2nd core biopsyTiming35 +/- 4 daysIf no drug change:55 +/- 5 days. If drug change:2-3 weeks after start of new drugs:•3-weekly: at 16 +/- 2 days•Bi-weekly: at day of 2nd dose•Weekly: at day of 4th dose

Primary ObjectivesDescriptionEndpointsi.1.Phase 1: Determine 2 RDI cut-offs to have a diagnostic test optimized in terms of predictive values2.Phase 2: Establish performance characteristics for first cut-off in terms of NPVNPVPPVSecondary Objectivesi.Assess NPV in subgroups by subtypeNPVii.Assess PPV in HER2+PPViii.Compare pCR prevalence and DFS in zones 1-3 for all patients and by subgrouppCRDFSv.Test for association btw. cancer subgroups and test resultTest result (zones 1-3)vi.Compare RDA and other biomarker results (Ki67, tumor grade)

Citation Format: Maureen Trudeau, Joke Tio, Foluso Ademuyiwa, Thierry Petit, Bryan Hennessy, Marina Cazzaniga, Daniele Generali. RNA disruption assay (RDA) - Breast cancer response evaluation for individualized therapy (brevity/brevity-02) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr OT2-03-01.