Are Patients Taking Oral Cancer Regimens as Prescribed?

Between 21% and 28% of patients taking an oral therapy for hepatocellular carcinoma (HCC) were nonadherent to treatment. Certain groups of patients may benefit from counseling services that promote improved adherence.

Oral therapies are more convenient than injectable therapies, but when patients no longer receive infusions of chemotherapy at a treatment center, reduced adherence becomes an important treatment concern. With standard treatments for HCC and other cancers transitioning from intravenous therapy to oral therapy, adherence is becoming an important consideration in treatment preference.

Patients have received sorafenib, an oral therapy for HCC, since approval for the HCC indication in 2007. Researchers at Daiichi Sankyo studied patient adherence to sorafenib using a registry of medical data to identify patients who had received 2 or more prescriptions for sorafenib for HCC over a 6-year period. Investigators analyzed data from 1127 patients. More than three-quarters (78.4%) of patients were male, and the average patient age was 61 years.

Using a measure of medication adherence called proportion of days covered (PDC), investigators recorded the percentage of days each patient had access to therapy. With this measure, late pharmacy refills indicate suboptimal adherence. Investigators found that 28.0% of patients did not have access to medication on 15% of treatment days, and 21.1% of patients did not have access to medication on 20% of treatment days.

Using a logistic regression, investigators then identified patient factors that correlate with lower adherence. Results of the analysis showed significantly higher rates of poor adherence in older groups of patients (P = .022), groups of patients with more comorbid illnesses (P = .002), and groups of patients taking more medications (P = .003).

This study may have underestimated adherence levels because investigators did not analyze data from patients who had prior cancers, potentially excluding patients with poorer health. Additionally, the PDC measure (1) only indicates that a medication is available and (2) does not prove that each dose was actually taken.

Despite these minor drawbacks, the investigators identified several patient characteristics associated with poor adherence. Recognizing these factors may help health care professionals identify patients in need of additional counseling, medication administration aids, or electronic reminder devices. Medication support programs from pharmaceutical companies, educational materials, and educational programs may help patients taking oral cancer regimens achieve better outcomes.