Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high-risk, early breast cancer

Background: The randomized, double-blind OlympiA trial compared 1 year of the oral poly(adenosine diphosphate-ribose) polymerase inhibitor, olaparib, to matching placebo as adjuvant therapy for patients with pathogenic or likely pathogenic variants in germline BRCA1 or BRCA2 (gBRCA1/2pv) and high-risk, human epidermal growth factor receptor 2-negative, early breast cancer (EBC). The first pre-specified interim analysis (IA) previously demonstrated statistically significant improvement in invasive disease-free survival (IDFS) and distant disease-free survival (DDFS). The olaparib group had fewer deaths than the placebo group, but the difference did not reach statistical significance for overall survival (OS). We now report the pre-specified second IA of OS with updates of IDFS, DDFS, and safety. Patients and methods: One thousand eight hundred and thirty-six patients were randomly assigned to olaparib or placebo following (neo)adjuvant chemotherapy, surgery, and radiation therapy if indicated. Endocrine therapy was given concurrently with study medication for hormone receptor-positive cancers. Statistical significance for OS at this IA required P < 0.015. Results: With a median follow-up of 3.5 years, the second IA of OS demonstrated significant improvement in the olaparib group relative to the placebo group [hazard ratio 0.68; 98.5% confidence interval (CI) 0.47-0.97; P = 0.009]. Four-year OS was 89.8% in the olaparib group and 86.4% in the placebo group (Δ 3.4%, 95% CI -0.1% to 6.8%). Four-year IDFS for the olaparib group versus placebo group was 82.7% versus 75.4% (Δ 7.3%, 95% CI 3.0% to 11.5%) and 4-year DDFS was 86.5% versus 79.1% (Δ 7.4%, 95% CI 3.6% to 11.3%), respectively. Subset analyses for OS, IDFS, and DDFS demonstrated benefit across major subgroups. No new safety signals were identified including no new cases of acute myeloid leukemia or myelodysplastic syndrome. Conclusion: With 3.5 years of median follow-up, OlympiA demonstrates statistically significant improvement in OS with adjuvant olaparib compared with placebo for gBRCA1/2pv-associated EBC and maintained improvements in the previously reported, statistically significant endpoints of IDFS and DDFS with no new safety signals

L’année 2021 dans tous ses états : une synthèse digérée

International audience5548 Background: Ovarian cancer is the leading cause of death by gynecological cancer. Complete surgery remains one of the main prognostic factors. Laparoscopic exploration is mandatory to assess surgical resectability at diagnosis or after neoadjuvant chemotherapy. However, there is no clinical or biological marker that can correctly predict resectability and may be able to avoid a second laparoscopic exploration for initially unresectable diseases. Our aim was to assess circulating tumor DNA (ctDNA) value as a predictive non-invasive marker of evolution towards resectability for patients with epithelial ovarian cancer receiving first-line chemotherapy. Methods: We explored in this work one of the secondary objectives of the CIDOC study (NCT03302884). CIDOC is a multicenter prospective study aiming to explore ctDNA value as early marker of disease relapse after first-line treatment for epithelial ovarian cancer. Patients with mucinous histology or early stages not requiring chemotherapy are excluded. Plasma samples are collected at diagnosis, during neoadjuvant chemotherapy, and during follow-up. After DNA extraction, panel-based next generation sequencing is performed on both tumor samples and germline DNA, and somatic mutations of interest are selected for ctDNA monitoring. ctDNA analyses are conducted using droplet digital PCR (BioRad QX200) by measuring the variant allele fraction (VAF) of previously identified mutations. Results: This intermediary analysis has included 47 patients diagnosed between March 2017 and December 2019. Median age was 69 years old (48 – 84). Most of the patients had advanced disease (89.4% stage FIGO III or IV), serous histology (94.8%), and high grade tumor (92.3%). Most of the patients underwent complete interval cytoreductive surgery (76.3% vs 17.4% complete upfront surgery). Most of the tumors had TP53 mutations (85.1%), following by alterations involving DNA repair genes (38.3%). Median cell-free DNA concentration at baseline was 0.38 ng/µL (0 – 12.8). ctDNA was identified in 92.1% of patients at baseline with a median VAF of 1.84% (0 – 42.52%). ctDNA VAF was correlated to the peritoneal dissemination ( p= 0.039) assessed with the peritoneal cancer index. ctDNA clearance after preoperative chemotherapy tended to be correlated to achievement of complete interval surgery for patients receiving neoadjuvant chemotherapy ( p= 0.108). Conclusions: ctDNA may be a promising non-invasive marker to assess peritoneal cancer spreading and to predict surgical resectability after neoadjuvant chemotherapy. If confirmed in larger populations, this may enable to avoid additional surgical explorations for patients who remain ctDNA positive after chemotherapy. Clinical trial information: NCT03302884

Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high-risk, early breast cancer

International audienc