The number of new prescriptions reported since the implementation of Medicare Part D could be artificially inflated due to patients changing plans.

"New prescription growth would be higher due to patients switching to new plans and not refilling scripts covered by their old plans," IMS said in a recent report to clients.

The number of new scripts for certain classes of drugs saw high jumps in year-to-year and sequential growth during the first months of Part D. The Medicare drug benefit went into effect Jan. 1.

New scripts for diabetes therapies increased by 27%, from approximately 3.1 bil. in January 2005 to 4 bil. in January 2006. Over the same period, new Rxs for cholesterol-reducing drugs increased 16%, from 5.1 bil. to 6 bil.

The highest sequential growth was seen in cholesterol-reducing drugs (13%) and anti-ulcerants (12%). Between December 2005 and January 2006, the number of new scripts for cholesterol-reducing drugs and anti-ulcerants increased by 686,429 and 484,968, respectively.

Pfizer's LDL-lowering therapy Lipitor (atorvastatin) falls under one of the drug classes showing rapid growth. The firm expects that the number of new scripts for Lipitor and other chronic therapies will be positively impacted by the "Welcome to Medicare" physicals included in the Medicare Modernization Act (¹ Also see "Tough Sell? Pfizer CEO Outlines Lipitor Game Plan For Generic Zocor" - Pink Sheet, 9 January, 2006., p. 8).

Several other classes, such as adrenergic blockers, seizure disorder drugs and antihypertensives, also experienced marked growth. The year-to-year growth of new prescriptions for adrenergic blockers and seizure disorder drugs jumped 14%, while sequentially, new scripts for antihypertensives rose 10%.

The dramatic rise in new scripts has compelled observers to raise red flags regarding glitches in data collection accompanying the implementation of Part D.

Wyeth has maintained that the underlying performance of Enbrel (etanercept) in the TNF inhibitor market, in terms of new scripts, has been inaccurately reflected due to IMS' difficulties in compiling the data following the drug benefit's launch.

The analyst community has expressed similar concern with the potential inflation of new Rx numbers.

In its report, IMS provides alternative explanations for the large growth in new scripts since the start of Part D, including the expanded drug coverage for seniors and reduced importation from Canada.

According to a recent HHS report, the number of beneficiaries enrolled in Medicare Part D as of Feb. 13 was 25.4 mil. - an increase of 3.9 mil. patients since December.

"This increased enrollment could drive [new] Rx growth as well if seniors that were not covered before are not able to get coverage and treatment under this new program," IMS explained.

IMS observed stronger growth both in new and total Rxs for chronic, age-related conditions, such as anti-diabetes, antihypertensive and cholesterol-reducing medicines, over treatments for acute conditions. By comparison, new Rxs for anti-infectives saw no yearly growth and 1% sequential growth.

Furthermore, more seniors who were previously buying their drugs in Canada or through Canadian Internet pharmacies may be "opting to purchase their prescriptions here in the U.S.," IMS said.

IMS cited an International Pharmacy Association estimate "that cross-border sales have fallen as much as 30% since the Medicare drug benefit coverage went into effect."

Compared to the rapid growth in new scripts, IMS estimates a 4.8% year-over-year rise in total scripts in January. Sequentially, total Rxs grew 1.2% between December and January, the firm said.

IMS is also investigating the potential for duplicate records from retailers seeking reimbursement from multiple sources for a single script. The company said it "foresaw this possibility and installed a process to identify multiple records coming from the retail and long-term care channels."

While IMS is excluding 300,000 duplicate records per week from the production systems, the firm is storing the duplicates for further analysis.

New Scripts May Be Juiced By Plan Switches Accompanying Part D – IMS

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