OBJECTIVES: Maintenance therapy with the poly(ADP-ribose) polymerase inhibitor olaparib, following response to platinum-based chemotherapy, significantly extends progression-free survival (PFS) and time to first subsequent treatment or death in patients with gBRCAm PSROC. We evaluate the impact of radiographic progression and subsequent therapy on health state utility values (HSUVs) of patients in the ENGOT-OV21/SOLO2 clinical study.

METHODS: HSUVs were derived from Euroqol 5-dimension 5-level (EQ-5D-5L) data using Devlin UK value set and cross-walk algorithms. Linear mixed-effects regression models were used to assess the impact of a selection of covariates on HSUVs in the trial population. Covariates included age, treatment arm (olaparib or placebo), follow-up period, baseline utility, and time-to-event outcomes: disease progression (progression vs progression-free) and first subsequent therapy (subsequent therapy vs no subsequent therapy). Independent review committee (IRC) and investigator-assessed reported progression were included for assessment. Analyses were conducted using both sets of HSUVs and reported separately for IRC and investigator-assessed PFS and subsequent therapy.

RESULTS: Progression and subsequent therapy demonstrated a significant impact on HSUVs. For analyses based on the Devlin algorithm, utility decrements with respective 95% confidence intervals were -0.042 (-0.026 – -0.059), -0.057 (-0.042 – -0.073), and ‑0.086 (-0.068 – -0.104) for IRC and investigator-assessed PFS and subsequent therapy, respectively. For the cross-walk, corresponding results were -0.050 (-0.032 – ‑0.069), ‑0.067 (-0.049 – -0.085), and -0.094 (-0.074 – -0.114). Similar trends were observed using both algorithms with utility decrements showing increasing order of magnitude from IRC PFS to investigator-assessed PFS to subsequent therapy. Subsequent therapy utility decrements were greater than 0.08 (minimal important difference).

CONCLUSIONS: Regression analyses demonstrated that gBRCAm PSROC patients on maintenance olaparib show a greater utility decrement associated with commencement of subsequent therapy than with radiographic progression. This is likely due to symptoms emerging because of subsequent therapy rather than symptoms associated with radiographic progression.