Utilization of Poly(ADP-Ribose) Polymerase Inhibitors in Ovarian Cancer: A Retrospective Cohort Study of US Healthcare Claims Data

Abstract

Introduction: We aimed to characterize real-world utilization of poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi) in women with ovarian cancer (OC).

Methods: This retrospective observational study of claims data from US MarketScan^® Commercial/Medicare Supplemental databases included women with OC initiating olaparib, niraparib, or rucaparib from January 1, 2017, to May 31, 2019. Patients were observed from first outpatient prescription until at least 30 days' follow-up. Clinical events of interest (CEIs), based on adverse reactions in PARPi prescribing information, were identified from claims using ICD-9/10 codes. Other outcomes included dose modification, persistence, adherence, healthcare resource utilization (HCRU), and cost.

Results: Overall, 303, 348, and 162 women with OC received olaparib, niraparib, and rucaparib, respectively. During follow-up, risk of any CEI was higher with niraparib versus olaparib (odds ratio 3.36 [95% confidence interval 2.00-5.65]) and niraparib versus rucaparib (2.09 [1.10-3.95]), with no significant difference between rucaparib and olaparib (1.61 [0.93-2.79]). PARPi dose decreases were observed in 21.1%, 35.1%, and 30.2% of olaparib-, niraparib-, and rucaparib-treated patients, respectively. Persistence (no treatment gaps of more than 90 days) was significantly higher (P < 0.05) with olaparib (62.2%) versus niraparib (35.9%) and rucaparib (48.7%); adherence (medication possession ratio, MPR ≥ 80%) was 80.2% versus 38.6% and 63.2%, respectively (P < 0.001). Inpatient admissions and outpatient service use were higher with niraparib and rucaparib versus olaparib, reflected in mean (± standard deviation) total medical costs (excluding pharmacy) of $5393 ± 8828 for olaparib, $7732 ± 14,054 for niraparib, and $6868 ± 7929 for rucaparib.

Conclusion: Differences between the licensed PARPi were observed in the risk of experiencing a CEI, likelihood of dose modifications, ability to receive continuous PARPi therapy, HCRU, and costs.

Keywords: Dose modification; Healthcare resource utilization; Ovarian cancer; PARP inhibitors; Real-world evidence; Tolerability.

Fig. 1

Forest plot showing odds ratios and 95% confidence intervals for comparison of selected clinical events of interest in women with ovarian cancer treated with olaparib, niraparib, or rucaparib as the index PARPi regimen (2017–2019): a niraparib (N = 348)/olaparib (N = 303); b rucaparib (N = 162)/olaparib (N = 303); c niraparib (N = 348)/rucaparib (N = 162). OR > 1 favors the second drug in the comparison. CEIs listed as NC were not calculated because of the small number of events per cell (< 3 patients per group). AML acute myeloid leukemia, CI confidence interval, CEI clinical event of interest, MDS myelodysplastic syndromes, NC not calculable, OR odds ratio, PARPi poly(ADP-ribose) polymerase inhibitors

Fig. 2

a Persistence^a and b adherence^b to index PARPi regimen. *P < 0.05 versus olaparib; **P < 0.01 versus olaparib; ***P < 0.001 versus olaparib; ^†P < 0.05 versus niraparib; ^†††P < 0.001 versus niraparib; statistical comparisons were performed using chi-squared or Fisher’s exact tests for categorical variables and t tests for continuous variables. Error bars represent 95% Clopper–Pearson confidence interval. ^aPersistence: percentage of patients with no index PARPi regimen treatment gaps of more than 90 days or those who had at least 6 months of continuous enrollment [28]; ^bAdherence: MPR was measured as the ratio of the sum of days’ supply during the fixed 6-month (180­day) follow-up period, and patients with MPR < 80% were categorized as non-adherent [28]. MPR medication possession ratio, PARPi poly(ADP-ribose)polymerase inhibitors