High Copayments Stymie Treatment Adherence in CML

Roxanne Nelson

January 14, 2014

Before imatinib (Gleevec) came on the market, the prognosis for chronic myeloid leukemia (CML) was dismal; only 30% of patients survived 5 years after diagnosis. But imatinib has boosted the 5-year survival rate to 89% — as long as patients adhere to treatment.

But for some, adherence to therapy is just too expensive.

When the cost to the patient becomes too high, many will skip doses or stop the drug completely, according to a study published online December 23, 2013, in the Journal of Clinical Oncology. Specifically, patients with high copayments were 70% more likely to stop their medication, and 42% were more likely to skip doses.

Approximately 17% of patients with higher-than-average copayments and 10% with lower-than-average copayments discontinued their therapy during the first 6 months of treatment.

Tyrosine kinase inhibitors (TKIs) are among the most successful classes of targeted therapy in cancer medicine. However, despite the significant clinical benefits, it is estimated that at least 30% of patients are nonadherent, note Stacie B. Dusetzina, PhD, from the division of general medicine and clinical epidemiology at the University of North Carolina at Chapel Hill, and colleagues. Evidence suggests that missing even 15% of the prescribed dosage can lead to relapse because the cancer develops resistance to the drug.

There are numerous barriers to optimal adherence in patients with chronic diseases, and cost is one of the most studied, writes Walid F. Gellad, MD, MPH, from the Center for Health Equity Research and Promotion at the University of Pittsburgh, in an accompanying editorial.

"What is most striking about this analysis is not so much that cost is associated with nonadherence, but that there were high rates of discontinuation of these drugs in the first 6 months of treatment," he notes.

However, important questions about adherence to TKIs have not been answered in this analysis, he points out. One question relates to long-term adherence. These agents are meant to be life-long, and although "understanding rates of discontinuation and adherence in the first 6 months are critically important, rates later in the course of treatment are not known."

Study Details.

In their study, Dr. Dusetzina and colleagues examined trends in imatinib expenditures from 2002 to 2011 and assessed the association between copayment requirements and adherence. They used MarketScan claims data from 2002 to 2011 to identify adults who had initiated treatment with imatinib during that period and who had insurance coverage at least 3 months prior to starting imatinib therapy.

The cohort consisted of 1541 patients from 18 to 64 years of age (mean, 48.8 years). The copayments were primarily drug copayments, as opposed to coinsurance.

The primary outcomes were drug continuation and adherence; the primary independent variable was out-of-pocket expense for a 30-day supply of imatinib.

Copayments and coinsurance amounts varied considerably among patients, ranging from $0 to $4992. Mean total monthly expenditures for imatinib nearly doubled from 2002 to 2011 — from $2798 to $4892.

The median copayment was modest ($30 for a 30-day supply), probably because patients in this analysis represented the "best-case scenario" — they were privately insured with relatively generous employer-sponsored benefits, the authors note. But even in this setting, the impact of cost on discontinuation and adherence was large.

Problems With Prescribing Oral Chemotherapy

Oral chemotherapeutic agents such as TKIs are becoming increasingly available, giving patients a convenient and noninvasive treatment option, as previously reported by Medscape Medical News. However, these agents tend to come with a very high price tag, and both private and public insurance plans in the United States frequently require patients to cover a large portion of their cost.

Most plans cover oral chemotherapy under a prescription benefit, which tends to require higher copayments. In contrast, intravenous infusions are traditionally covered under a medical benefit, which tends to be more generous in its coverage. This duality in coverage was never meant to interfere with life-saving treatment, and the original intention of copayments and coinsurance was to limit unnecessary and inappropriate unitization of drugs.

Steps are being taken to reverse this disparity. "As of mid-2013, 23 states and the District of Columbia had passed 'oral cancer parity' legislation," Dr. Dusetzina explained. "This is a step in the right direction for patients."

However, one limitation of these state laws is that they don't apply to all health plans, she told Medscape Medical News. "For example, parity only extends to patients on private health insurance, not to those on Medicare and Medicaid," she said. "Additionally, about 60% of privately insured people are on plans that are exempt from state parity laws."

These laws should improve access to oral therapies for patients, or at least ensure that the cost to patients appropriately prescribed oral therapies is similar to that of infused treatments. In addition, the Affordable Care Act (ACA) will help limit out-of-pocket expenses. "The ACA includes prescription medications," explained Dr. Dusetzina. "The maximum out-of-pocket expense for each year is set at $6350 per individual and $12,700 per family. Prior to the ACA, most drug plans did not have maximums, so this is a major improvement for patients with very expensive prescription medications."

Making these therapies more affordable is a very complex problem, Dr. Dusetzina noted. "Part of making treatments more affordable to patients is improving insurance-benefit designs to reduce patient cost sharing," she said. "The other part is related to drug pricing itself, which is not transparent in the United States."

She added that imatinib will soon become generic, which should help reduce the cost to patients and insurers. However, there could be a shift away from imatinib toward some of the newer — and more expensive — TKIs.

Whatever needs to be addressed should probably take place in oncologists' offices, suggests Dr. Gellad.

A number of innovative solutions are being proposed to improve treatment adherence, but it is unclear if they can be applied to TKIs, he writes. "Whatever solution is developed for improving adherence to TKIs, whether addressing cost or one of the other numerous barriers to adherence, it is clear that assessments of adherence will need to become routine in oncology offices."

Another complicating issue is uncertainty about the most appropriate threshold to use when measuring adherence.

"Do patients need to be 100% adherent to their medications (namely, take 100% of the pills in a given time period) to receive the benefit, or can they take 95%, or 90%?" Dr. Gellad asks.

The authors have disclosed no relevant financial relationships.

J Clin Oncol. Published online December 23, 2013. Abstract, Editorial


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