Adherence to Oral Treatments in Older Patients with Advanced Prostate Cancer, the ADHERE Study: A Prospective Trial of the Meet-URO Network

Abstract

Background Novel androgen receptor signaling inhibitors for prostate cancer (PC) impose the burden of self-administration on older patients overwhelmed by the requirement of many other concomitant medications. Patients and Methods This study evaluated the proportion of non-adherence in a 12-month follow-up period and the first 3 months to abiraterone (ABI) or enzalutamide (ENZ). In a prospective multicenter observational cohort study, patients with metastatic castration-resistant PC (mCRPC) aged ≥70 years receiving ABI or ENZ pre- or post-docetaxel were enrolled. Treatment monitoring included pill counting, a self-assessment questionnaire, and clinical diaries at each clinical visit. Non-adherence rates were based on proportions of missed/prescribed pills ratios by pill counting. Results Overall, 234 patients were recruited with median age of 78 years (range, 73–82); 86 (37%) were treated with ABI, and 148 (63%) with ENZ. The median follow-up for adherence was seven monthly cycles (IQR: 4–12). The two cohorts were well balanced for baseline characteristics. The percentage of non-adherence by pill counting was slightly higher for ABI than ENZ (5.2% vs. 4.2%, P < .001). By self-reporting, patients on ENZ tended to report more frequently than those with ABI forgetfulness as the reason for missing events (42% vs. 17%, P < .001). A lower Geriatric G8 score correlated with non-adherence (P = .004). Overall survival (OS) was 48.8 months. Patients on ABI had radiographic progression-free survival (rPFS) of 28.4 [24.2–32.5], while for ENZ patients, we reported a median rPFS of 23.1 [18.2–28.1] months. Conclusion Physicians tend to treat older mCRPC patients with ENZ. Non-adherence rate is relatively low overall but can be higher with ABI than with ENZ and correlates with the Geriatric G8 score. Forgetfulness is a potential barrier for ENZ.

Androgen receptor pathway inhibitors, prostate cancer, and older adults: a global Young International Society of Geriatric Oncology drug review

“…Abiraterone users in this cohort were found to have a longer PFS [28.4 (24.2–32.5) versus 23.1 (18.2–28.1) months, p = 0.041]. 66 …”

The Geriatric G8 Score Is Associated with Survival Outcomes in Older Patients with Advanced Prostate Cancer in the ADHERE Prospective Study of the Meet-URO Network

“…While PSA responses have been invariably associated with PFS and OS on hormonal treatments, without satisfying Prentice’s criteria for surrogacy [ 23 ], to the best of our knowledge, this is the first prospective study aiming to evaluate the G8 screening in mCRPC and showing its correlation with rPFS and OS. In the ADHERE study, we could not demonstrate an association between a reduced adherence to ARPIs and rPFS or OS, although the G8 was significantly linked to treatment adherence [ 10 ]. Therefore, we reckon that the reduced OS and rPFS of patients with a G8 score > 14 likely mirror the general health status as demonstrated in other cancer patients.…”

“…An abnormal G8 score (>14 on a scale from 0 to 17) was strongly associated with mortality in almost a thousand cancer male patients aged ≥ 70 [ 7 ]. We have previously reported that the G8 score is an associated factor with adherence to ARPIs in older mCRPC patients [ 8 , 9 , 10 ]. In the current analysis, we investigated the clinical baseline and on-ARPI variables associated with radiographic progression-free survival (rPFS) and overall survival (OS).…”

Adherence to Hormonal Therapies in Prostate Cancer

“…19 Results from another Italian study, evaluating 234 mCPRC patients treated with AA (N = 86) or ENZ (N = 148) pre- or post-docetaxel, indicated that nonadherence by pill counting had a rate of 5.2% for AA vs 4.2% for ENZ ( P < .001). 20…”

“…19 Results from another Italian study, evaluating 234 mCPRC patients treated with AA (N ¼ 86) or ENZ (N ¼ 148) pre-or post-docetaxel, indicated that nonadherence by pill counting had a rate of 5.2% for AA vs 4.2% for ENZ (P < .001). 20 Based on a different methodology as described previously, results from a 2-arm prospective randomized trial conducted at 6 sites in the US and Singapore indicated that adherence to AA prescribed for metastatic PC using validated adherence questionnaires was measured at 91.69%-98.18% depending on the medication dose and schedule. 21 Treatment adherence was also high in 193 patients with nonmetastatic CRPC initiated on apalutamide, a recently approved oral antiandrogen therapy.…”