Perspectives on Adherence and Persistence With Oral Medications for Cancer Treatment

Abstract

Novartis, East Hanover, NJ As oral cancer therapies are developed, a high degree of persistence and adherence is necessary for optimal outcomes. Ensuring persistence, continuing treatment for the prescribed duration, and adherence-taking medication as prescribedhas been a challenge to patient management and health care cost containment in real-world settings. 1 It may appear as though persistence and adherence to oral cancer therapies is superior to that observed with oral noncancer therapies. 2 Indeed, patients with cancer tend to be highly motivated, to prefer oral therapies, and to exhibit high persistence and adherence in clinical trials. 3 However, emerging real-world data indicate otherwise.Persistency rates for oral cancer medications are generally lower in real-world settings compared with in clinical trials (Table 1), 4-20 especially for chronically administered medications. Persistence with tamoxifen at 3.9 years was 71.7% in the Arimidex, Tamoxifen Alone or in Combination (ATAC) trial, 6 but persistence was only 64.8% at 3.5 years among women identified in a pharmacy database. 5 The difference may be more pronounced in the elderly. 9,12 Similarly, persistence with letrozole was 84% at 4.25 years in the Breast International Group 1-98 trial, 5 but it was only 77% at 1 year in an analysis of two large-claims databases (data on file, Novartis, East Hanover, NJ). This difference remains despite inclusion of 23% of patients with a Ն 30-day treatment gap (Figure 1). Differences were not limited to patients with breast cancer. In the IRIS (International Randomized Study of Interferon Versus ST1571) trial, patients with chronic myelogenous leukemia (CML) persisted with imatinib at a rate of 91% at 19 months. 4 By contrast, real-world persistence at 12 and 24 months among patients with CML and GI stromal tumors was 56% and 41%, respectively, when dosing gaps Ն 30 days were disallowed (data on file, Novartis, East Hanover, NJ). In addition, pharmacy records from 4,043 patients demonstrated a decrease in imatinib persistence from 100% to 23% between months 4 and 14 of treatment. 21 There is less information on adherence compared with persistence in clinical trials. In the adherence companion study 60104 to Cancer and Leukemia Group B 49907, adherence to capecitabine in elderly patients with breast cancer was 78% during the prescribed six cycles of therapy. 18 In the real world, a 96.7% adherence was observed. 20 However, capecitabine is not a chronic therapy, and in this study, adherence was measured for only 44.3 days (two cycles). The majority of adherence data is from the real-world setting, and these have shown variability (Table 1). Analysis of claims data demonstrated 89% adherence to imatinib among patients with CML at 1 year when unlimited dosing gaps were allowed (data on file, Novartis, East Hanover, NJ). It was 78% at 2 years according to pharmacy records. 21 Among patients with breast cancer, 54% to 80% of patients receiving hormonal therapy have been shown to adhere to treatment (data on fil...

Persistence and Compliance with Pazopanib in Patients with Advanced Renal Cell Carcinoma Within a U.S. Administrative Claims Database

“…However, dosing and adherence to these treatments outside of the clinical trial setting has not been well studied, and may be lower than that in clinical trials. 9 Having a better understanding of such outcomes may help oncologists and payers to make more informed decisions regarding treatment choices and reimbursement of these medicines. [10][11][12] The primary objective of the current study was to estimate medication persistence and compliance (adherence) among patients with advanced RCC receiving pazopanib as first-line therapy or after previous treatment with ≥ 1 other therapies outside the clinical trial setting.…”

Adherence, compliance and persistence to oral antineoplastic therapy: a review focused on chemotherapeutic and biologic agents

“…However, patients require active physician participation in guiding their decision to take oral versus intravenous therapy, and most patients attribute their preference for oral chemotherapy to convenience and problems linked to intravenous access. Despite optimal adherence and persistence are a necessary prerequisite to achieve the best possible clinical outcome, clinical research has shown that a significant percentage of patients report suboptimal adherence, which may be even far lower in the real-word populations outside of clinical trials [83]. Poor adherence has also a negative reflex on medical costs and may increase the use of medical resources.…”

Compliance with adjuvant capecitabine in patients with stage II and III colon cancer: comparison of administrative versus medical record data

“…While oral agents pose many notable advantages when compared to conventional parenteral drugs, including enhanced convenience of self‐administration, reduced hospital and societal costs, and improved patient engagement in their own care 1, 2, 3, 4, these benefits must be balanced against growing concerns regarding poor compliance to treatment and its potentially negative impact on outcomes 1, 2, 3, 4, 5, 6. Suboptimal adherence to medications is a commonly recognized problem for many chronic medical conditions, such as hypertension and diabetes mellitus, where it has been shown to compromise drug effectiveness 7, 8, 9, 10.…”

“…The majority of studies on medication compliance in oncology have focused on oral hormonal therapies in breast cancer 5, 6, 11, 12, 13 even though oral drugs are also frequently used in other cancers 14, 15, 16, 17. In colon cancer, the oral 5‐fluorouracil prodrug known as capecitabine is a commonly prescribed component in a large number of systemic therapy regimens 18, 19, but it has received relatively little focus to date 20, 21, 22, 23.…”