Surprise! Breast Cancer Patients Stay on Affordable AIs

Neil Osterweil

December 13, 2013

SAN ANTONIO — Lower your prices and the customers will keep coming. It works in retail and it works in hormonal therapy, too, evidently.

A study of the drug compliance habits of more than 13,000 women older than 50 years with early-stage breast cancer showed that women who used a cheaper generic aromatase inhibitor (AI), rather than a brand-name product, were significantly more likely to stay on their drugs and take them as directed, explained Dawn L. Hershman, MD, from the Columbia University Medical Center in New York City.

Out-of-pocket drug costs, in the form of copays, appeared to be a major deciding factor; as the cost of monthly copays went up, adherence went down, Dr. Hershman reported here at the 36th Annual San Antonio Breast Cancer Symposium (SABCS).

According to the researchers, mean copayment cost for a 30-day prescription was $7.74 for tamoxifen, $9.04 for a generic AI, and $33.30 for a brand-name AI.

These results could have long-term implications for patients. "We know that survival may be improved by increasing access to medications," Dr. Hershman said.

Noncompliance is a problem with all antiestrogens, said Aditya Bardia, MBBS, MPH, from the breast cancer division at the Massachusetts General Hospital Cancer Center in Boston, who was not involved in the study.

"Adherence to hormonal therapies is an issue, not only with aromatase inhibitors, but also with tamoxifen," he told Medscape Medical News.

He noted that current recommendations for postmenopausal women with breast cancer are for 5 years of tamoxifen followed by 5 years of an AI.

"Ten years is a long therapy, so compliance is a big issue. Whatever we can do to help with compliance would be great," said Dr. Bardia.

He explained that musculoskeletal symptoms with AIs often cause patients to discontinue the drugs or switch to another agent, and that cost is an important consideration for many patients.

Dr. Hershman said that noncompliance with hormonal therapy is associated with several different factors, including demographics, toxicities, patient health behaviors, medication frequency and dosing characteristics, and out-of-pocket costs. In the United States, the cost of all oral medications, including hormonal therapies, increased from $40 billion in 1999 to $234 billion in 2008.

Most pharmacy plans ask patients to shoulder some of the increased cost in the form of copays and deductibles, or limit access to expensive medications through dispensing limits and/or preauthorization.

A recent survey of cancer patients found that drug costs were associated with some form of nonadherence to therapy in 45% of patients, Dr. Hershman noted.

Combing Through Data

Dr. Hershman and colleagues compared AI use before and after generic products became available in 2010 to determine whether their introduction made a difference in compliance and adherence rates. They also looked at the discontinuance of tamoxifen, brand name AIs, and generic AIs, and whether adherence to the drugs changed over time.

They defined early discontinuation as stopping the medication entirely, with at least a 45-day gap after the most recent dispensing should have been completed, and nonadherence as taking medication for less than 80% of the prescribed time.

They sampled the Optum Database, which contains information on 25 million commercially insured patients, 6 million Medicare patients, and 2 million Medicaid patients.

The study involved 13,522 women older than 50 years who were diagnosed with early-stage breast cancer from 2007 to 2011 and who filled at least 2 prescriptions for hormonal therapy.

Of this group, 5990 switched drugs at some time, and 72.9% switched from a brand-name AI to a generic AI.

Of those who did not switch, the majority had commercial insurance with no deductible.

Copayments for a 30-day prescription were higher than $20 for 29.8% of the patients, $10 to $20 for 28.4%, and less than $10 for 41.8%.

On multivariate analysis, factors significantly associated with the discontinuation of a drug were the use of a brand-name AI, compared with a generic AI (hazard ratio [HR], 0.62; < .001), a copay from $10 to $20 (HR, 1.21; = .001), and a copay of more than $20 (HR, 1.59; P < .001).

The analysis was adjusted for year, deductible type, coverage type, provider, surgery, comorbidity, age, race, education, income, and geographic region.

Similarly, in an analysis controlling for the same factors, characteristics significantly associated with better adherence were the use of a generic AI, compared with a brand-name AI (odds ratio [OR], 1.37; P < .01), and an income level above $100,000 per year (OR, 1.38; = .003). A higher copay, a low income, the use of a brand-name AI, and the use of tamoxifen were all negatively associated with adherence.

Dr. Hershman noted that the results only reflect the 2 years after the introduction of generic AIs. In addition, the researchers lacked information on tumor characteristics that could have resulted in a drug change. She acknowledged that women with a higher copay might have had other reasons for being noncompliant, and that they measured adherence by prescription refills rather than by actual use.

The Cancer Treatment Fairness Act, a state-level bill passed by at least 26 state legislatures, would "prohibit higher copayments, regardless of the benefit category," she noted.

Local pricing can vary widely, said perennial SABCS commentator Steven Vogl, MD, an oncologist in private practice in the Bronx, New York, in the discussion after the presentation. He said that Dr. Hershman and colleagues estimated the cost of a 30-day supply of generic anastrozole to be $110. In New York City, the price swings much lower and higher than that amount, he said.

"There's one popular chain that is still charging $200 for a 30-day supply, and there are neighborhood pharmacies in New York that charge $16 for a 30-day supply," he said.

He also noted, and Dr. Hershman agreed, that some patients choose to pay the higher cash price out of pocket, rather than have to deal with insurance company claims, and that these patients were likely not captured in the database.

The study was supported by the American Cancer Society, the Breast Cancer Foundation, and the National Cancer Institute. Dr. Hershman and Dr. Vogl have disclosed no relevant financial relationships.

36th Annual San Antonio Breast Cancer Symposium (SABCS): Abstract S3-04. Presented December 12, 2013.


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