Window-of-opportunity trial of olaparib and durvalumab before standard neoadjuvant chemotherapy for stage II/III triple-negative or ER-low breast cancer (MEDIOLA WOO): whole-exome and transcriptome profiling of serial tumor biopsies

The MEDIOLA window-of-opportunity (WOO) trial (ESR-16-11923; NCT03594396) was a single-arm, non-randomized, open-label study conducted at Seoul National University Hospital in 54 female patients with stage II/III triple-negative or estrogen receptor (ER)-low breast cancer. Patients received olaparib 300 mg twice daily for 4 weeks with a single 1500 mg dose of durvalumab on day 15, followed by standard neoadjuvant chemotherapy. The primary objective was to characterize changes in tumor biology through serial biopsies obtained at baseline, day 14 (on-treatment 1; OT1, after olaparib alone and before durvalumab), and day 29 (on-treatment 2; OT2, after olaparib plus durvalumab). This study comprises two sequencing datasets. Whole-exome sequencing was performed on baseline tumor biopsies with matched peripheral-blood germline DNA from all 54 patients (54 tumor-normal pairs). RNA sequencing was performed on fresh-frozen serial tumor biopsies, yielding 160 libraries (baseline n = 54, OT1 n = 54, OT2 n = 52; two patients did not undergo OT2 biopsy). All libraries were sequenced on an Illumina NovaSeq 6000 platform. Raw sequence data are provided here under controlled access; processed RNA-seq quantification files are available through the Gene Expression Omnibus.

• Type: Cancer Genomics
• Archive: European Genome-phenome Archive (EGA)