Patients with prostate cancer who were non-adherent to advanced oral therapies experienced substantially higher health care resource utilization (HCRU) than those who were adherent, according to a study presented at the virtual 2021 ASCO Genitourinary Cancers Symposium.

“Prostate cancer is associated with a high clinical and economic burden. Advanced oral therapies have become the standard of care for patients with advanced prostate cancer, but real-world data on treatment patterns and their impact on HCRU are lacking,” wrote Dominic Pilon, Analysis Group, Inc, Montreal, Quebec, Canada, and colleagues.

This study aimed to describe treatment adherence factors associated with adherence, and the impact of adherence on HCRU among patients with prostate cancer who initiated oral therapies.

Symphony Health Solutions Patient Transactional Databases were used to identify patients who initiated apalutamide, enzalutamide, or abiraterone acetate for prostate cancer.

Adherence was defined using the proportion of days covered by advanced oral therapies during the 6-month period following the index date. A PDC ≥80% was considered adherent.

Multivariable logistic regression was used to evaluate baseline characteristics associated with adherence. Multivariable Poisson regression was used to compare all-cause and prostate cancer-related HCRU was assessed from 6 to 18 months post-index.

A total of 27,322 patients were identified. Overall, 81% of patients were aged ≥65 years, 60% were white, 48% had Medicare coverage, and 56% had metastatic disease.

At 6 months, 57% of patients were adherent to advanced oral therapies.

When looking at factors associated with adherence, patients aged 55-64 and 65-74 had greater odd of being adherent than those aged ≥75 years (24% and 22%, respectively). Black patients had 17% lower odds of being adherent compared with white patients (P <0.01).

In addition, patients with Medicare coverage had 23% greater odds of being adherent compared to those with commercial insurance (P <0.01). Patients with a below median primary insurer paid amount for their first advanced oral therapy claim had 13% greater odds of being adherent vs those above the median amount (P <0.05).

The study found that patients who were adherent had lower HCRU compared to those who were not. Adherent patients had 25% fewer all-cause inpatient days, 16% fewer all-cause emergency room (ER) visits, 18% fewer all-cause other non-outpatient services use, 30% fewer prostate cancer-related inpatient days, and 24% fewer prostate cancer-related ER visits (all P <0.01) compared to patients who were not adherent to advanced oral therapies.

“In this study, non-adherence over a 6-month period following [advanced oral therapy] initiation was associated with substantially higher [HCRU], including inpatient and ER visits. Moreover, non-adherence was widely observed, impacting over 40% of advanced prostate cancer patients in the first 6 months after [advanced oral therapy] initiation,” Pilon and colleagues concluded.—Janelle Bradley

Pilon D, Lamori J, Rossi C. Medication adherence among prostate cancer patients using advanced oral therapies. Presented at: the virtual 2021 ASCO Genitourinary Cancers Symposium; February 11-13, 2021. Abstract 44.