ATHENA (GOG-3020/ENGOT-ov45): a randomized, double-blind, placebo-controlled, Phase III study of rucaparib + nivolumab following front-line platinum-based chemotherapy in ovarian cancer

Background: The poly(ADP-ribose) polymerase (PARP) inhibitor rucaparib has demonstrated clinical activity in patients with ovarian cancer with or without homologous recombination (HR) deficiency (HRD; eg, a BRCA mutation or high genome-wide loss of heterozygosity [LOH high]). ATHENA (NCT03522246) is evaluating rucaparib + the anti-PD-1 antibody nivolumab as maintenance treatment following front-line platinum-based chemotherapy in patients with newly diagnosed, high-grade ovarian, fallopian tube, or primary peritoneal cancer. The rationale for evaluating this combination includes the following: tumors with a deleterious BRCAmutation express novel, tumor-specific protein sequences (neoantigens), which can attract PD-L1-expressing, tumor-infiltrating lymphocytes; ovarian tumors with HRD have more neoantigens relative to HR-proficient tumors and may respond preferentially to immune checkpoint inhibitors; and rucaparib combined with anti-PD-1 or anti-PD-L1 demonstrated improved antitumor activity in a syngeneic ovarian cancer BrKras (BRCA1-/-; TP53-/-; MYC; KRAS-G12D; AKT) model. Furthermore, it is hypothesized that DNA damage induced by PARP inhibition may increase neoantigens regardless of HRD status. Methods: Eligible patients must have completed first-line platinum doublet chemotherapy and surgery. Patients had to have achieved an investigator-assessed response without disease progression or rising CA-125 at any time during first-line platinum doublet treatment. Cytoreductive surgery (R0 permitted) could have been completed either prior to chemotherapy (primary surgery) or following neoadjuvant chemotherapy (interval debulking). Patients will be randomized 4:4:1:1 to receive maintenance treatment in Arm A (oral rucaparib 600 mg BID + intravenous [IV] nivolumab 480 mg on day 1 of every 4-week cycle), Arm B (oral rucaparib + IV placebo), Arm C (oral placebo + IV nivolumab), or Arm D (oral placebo + IV placebo). Stratification factors include centrally determined tumor HRD status (BRCA mutant, non-BRCA mutant/LOH high, non-BRCA mutant/LOH low, or non-BRCA mutant/LOH indeterminate), posttreatment disease status (residual vs no residual disease), and timing of surgery (primary vs interval debulking). The primary endpoint of investigator-assessed progression-free survival (per RECIST version 1.1) will be evaluated in 3 independent comparisons between arms: A vs B, A vs D, and B vs D. Secondary endpoints include blinded independent central review of progression-free survival, overall survival, investigator-assessed objective response rate, investigator-assessed duration of response, and safety. Enrollment is ongoing; patients (n∼1000) will be enrolled at >270 sites worldwide.