Studies show increase costs, higher use of specialty drugs to treat inflammatory autoimmune conditions

Biologic anti-inflammatory (BAI) specialty medications to treat autoimmune inflammatory conditions-such as rheumatoid arthritis (RA), psoriasis or inflammatory bowel disease (eg, Crohn’s disease, ulcerative colitis)-are among the most commonly used specialty drugs and costs are rising rapidly. Three new studies presented at the 2013 Academy of Managed Care Pharmacy’s 25^th Annual Meeting & Expo in San Diego, in April, highlighted the use, effectiveness, and cost trends for BAIs.

In the first study, St. Paul-based pharmacy benefit manager Prime Therapeutics (Prime) studied a sample of 2.6 million members who were continuously insured for 3 years to determine how many were diagnosed with a disease that could be treated with a BAI drug.

The analysis found 39,848 patients had medical claims that showed an autoimmune disease that could be treated with a BAI drug. During the study period, use of BAIs increased 29.4%. The most frequently used BAI drugs were adalimumab (Humira), etanercept (Enbrel) and infliximab (Remicade). However, just 10,769 members-or about 1 in 4-had a BAI claim.

“About 3 in 4 patients who could be treated with a BAI are not currently taking one,” said Patrick Gleason, PharmD, FCCP, BCPS, director of health outcomes at Prime. “Should a greater number of patients take these medications, use and costs could climb significantly.”

Effectiveness of BAI drugs

A second and related study compared the effectiveness of 3 of the most common BAI drugs-adalimumab, etanercept, and infliximab.

The study first reviewed 1,003 patients newly starting treatment for Crohn’s disease, of whom 494 were prescribed infliximab and 509 were prescribed adalimumab. Length of treatment was significantly shorter for patients taking infliximab, with 25% stopping treatment by 4 months and 50% by 16 months, compared to 6 months and 22 months for those treated with adalimumab.

Next, researchers reviewed 2,821 patients with new treatment starts for RA, of whom 284 were prescribed infliximab, 1,301 adalimumab, and 1,236 etanercept. Researchers found no major difference in the time to discontinuation among these three medications (a possible indication of problems with effectiveness), with 25% discontinuation at less than 4 months for all 3 drugs, and 50%  discontinuation for each at 13 months.

“Patients discontinued the drugs for RA at similar times, but discontinuation varied for patients taking the treatments for Crohn’s disease,” said Dr Gleason. “Discontinuing a therapy could suggest differences in effectiveness, or it could indicate differences in the patients receiving each treatment.”

In the final study, Prime researchers assessed the use and cost patterns for 2 BAI drugs, etanercept and adalimumab. In third quarter 2011, Prime placed etanercept in the non-preferred formulary tier, preferring adalimumab prior to etanercept; therefore, it was important to understand what effect this change may have had on daily dose utilization patterns and net ingredient costs. Prime reviewed 9 million commercial claims between January 2007 and June 2012 to evaluate dosing trends for each drug. For the entire BAI drug class, net ingredient cost trends (inclusive of rebates) were compared to ingredient cost and average wholesale price (AWP) trends.

The study found that, in fact, average doses for both drugs slightly decreased over the 4.5-year period. Average milligrams per day of etanercept decreased 6.5%  and average milligrams per day of adalimumab decreased 6.4%. At the same time, costs continued to rise for both drugs during the same period. Average daily gross costs for etanercept increased 38.3%, while average daily gross costs increased 38.4% for adalimumab. Researchers found increasing daily costs of these drugs is due to manufacturer price increases and not to increasing doses. Prime’s net ingredient cost per claim growth was lower at a 6.3% annual compound annual growth rate (CAGR) compared to 8.4% ingredient cost per claim CAGR and 8.9% AWP per claim CAGR. For health plans and insurers to manage spend in the autoimmune category, manufacturer negotiations and preferred channel management are necessary.

“These costs have become a significant burden for consumers and plan sponsors. It’s more important than ever to carefully monitor costs and available treatments to make sure members are getting the best value for their care,” said Dr Gleason.