Yann Christinat

Geneva Homologous Recombination Deficiency Test Is Predictive of Survival Benefit From Olaparib and Bevacizumab Maintenance in Ovarian Cancer

PURPOSE The ability of the Geneva homologous recombination deficiency (HRD) test to predict progression-free survival (PFS) in patients with high-grade ovarian cancer treated with poly (ADP-ribose) polymerase inhibitors has been demonstrated. Its performance with respect to overall survival (OS) has not been assessed yet. METHODS Using the final results of the PAOLA-1/ENGOT-ov25 phase III clinical trial with a median follow-up of 5 years, we evaluated the Geneva HRD test on 468 samples as part of the ENGOT HRD European Initiative. Results were evaluated in terms of final PFS and OS in the olaparib + bevacizumab and placebo + bevacizumab arms and compared with the Myriad MyChoice HRD test. RESULTS Final PFS was consistent with previously published data and confirmed the predictive value of the Geneva HRD test with a hazard ratio (HR) of 0.41 (95% CI, 0.30 to 0.57) for HRD-positive patients. The results for OS showed a HR of 0.56 (95% CI, 0.37 to 0.85) for HRD-positive patients and 1.6 (95% CI, 1.1 to 2.3) for HRD-negative patients. These results are consistent with those observed with the Myriad test, including the negative OS trend in the HRD-negative subgroup treated with olaparib + bevacizumab (HR, 1.2 [95% CI, 0.83 to 1.8]). A subgroup analysis of patients with intermediate HRD scores showed that the normalized large-scale state transition score used by the Geneva HRD test had both predictive and prognostic value. CONCLUSION The Geneva HRD test predicts PFS and OS benefit from olaparib + bevacizumab. The potential detrimental effect of olaparib + bevacizumab on OS in the HRD-negative population is hypothesis-generating and needs to be confirmed prospectively.

Normalized LST Is an Efficient Biomarker for Homologous Recombination Deficiency and Olaparib Response in Ovarian Carcinoma

PURPOSE The efficiency of the Myriad Homologous Recombination Deficiency (HRD) test to guide the use of poly (ADP-ribose) polymerase (PARP) inhibitors has been demonstrated in several phase III trials. However, a need exists for alternative clinically validated tests. METHODS A novel biomarker for HRD was developed using The Cancer Genome Atlas database and, as part of the ENGOT HRD European Initiative, applied to 469 samples from the PAOLA-1/ENGOT-ov25 trial. Results were compared with the Myriad myChoice Genomic Instability Score (GIS) with respect to the progression-free survival in the olaparib + bevacizumab and placebo + bevacizumab arms. RESULTS Analysis of the TCGA cohort revealed that a normalization of the number of large-scale state transitions by the number of whole-genome doubling events allows a better separation and classification of HRD samples than the GIS. Analysis of the PAOLA-1 samples, using the Geneva test (OncoScan + nLST), yielded a lower failure rate (27 of 469 v 59 of 469) and a hazard ratio of 0.40 (95% CI, 0.28 to 0.57) compared with 0.37 for Myriad myChoice (BRCAm or GIS+) in the nLST-positive samples. In patients with BRCAwt, the Geneva test identified a novel subpopulation of patients, with a favorable 1-year PFS (85%) but a poor 2-year PFS (30%) on olaparib + bevacizumab treatment. CONCLUSION The proposed test efficiently separates HRD-positive from HRD-negative patients, predicts response to PARP inhibition, and can be easily deployed in a clinical laboratory for routine practice. The performance is similar to the available commercial test, but its lower failure rate allows an increase in the number of patients who will receive a conclusive laboratory result.

High Concordance of Different Assays in the Determination of Homologous Recombination Deficiency–Associated Genomic Instability in Ovarian Cancer

PURPOSE Poly(ADP-ribose) polymerase inhibitors (PARPi) have shown promising clinical results in the treatment of ovarian cancer. Analysis of biomarker subgroups consistently revealed higher benefits for patients with homologous recombination deficiency (HRD). The test that is most often used for the detection of HRD in clinical studies is the Myriad myChoice assay. However, other assays can also be used to assess biomarkers, which are indicative of HRD, genomic instability (GI), and BRCA1/ 2 mutation status. Many of these assays have high potential to be broadly applied in clinical routine diagnostics in a time-effective decentralized manner. Here, we compare the performance of a multitude of alternative assays in comparison with Myriad myChoice in high-grade serous ovarian cancer (HGSOC). METHODS DNA from HGSOC samples was extracted from formalin-fixed paraffin-embedded tissue blocks of cases previously run with the Myriad myChoice assay, and GI was measured by multiple molecular assays (CytoSNP, AmoyDx, Illumina TSO500 HRD, OncoScan, NOGGO GISv1, QIAseq HRD Panel and whole genome sequencing), applying different bioinformatics algorithms. RESULTS Application of different assays to assess GI, including Myriad myChoice, revealed high concordance of the generated scores ranging from very substantial to nearly perfect fit, depending on the assay and bioinformatics pipelines applied. Interlaboratory comparison of assays also showed high concordance of GI scores. CONCLUSION Assays for GI assessment not only show a high concordance with each other but also in correlation with Myriad myChoice. Thus, almost all of the assays included here can be used effectively to assess HRD-associated GI in the clinical setting. This is important as PARPi treatment on the basis of these tests is compliant with European Medicines Agency approvals, which are methodologically not test-bound.