Utilization, cost trends, and member cost-share for self-injectable multiple sclerosis drugs--pharmacy and medical benefit spending from 2004 through 2007.
BACKGROUND
In 1993, interferon beta-1b became the first of 4 self-injectable multiple sclerosis (MS) drugs to be approved by the U.S. Food and Drug Administration. Initially covered as a medical expense, self-injectable MS drugs are increasingly considered specialty pharmaceuticals and are often covered under the pharmacy benefit. Self-injectable MS drugs are expensive, costing approximately $2,000 per month per patient in 2007.


OBJECTIVE
To (1) determine the trends for price and utilization of self-injectable MS drugs, (2) meld medical and pharmacy claims data to capture total health care spending on self-injectable MS drugs, and (3) calculate the out-of-pocket cost-share for members with pharmacy benefits.


METHODS
A pharmacy benefits manager with integrated medical claims for approximately 1.8 million commercial members, about 20% of its total of 9 million commercial members, analyzed self-injectable MS pharmacy claims for a 45-month period beginning in January 2004 and ending in September 2007 and integrated medical and pharmacy claims for a 42-month period beginning in January 2004 and ending in June 2007. The 9 million members are beneficiaries of 10 Blue Cross Blue Shield (BCBS) health plans distributed throughout the United States, and the subset of 1.8 million members are enrolled in 1 BCBS health plan in the Northern Plains states. Self-injectable MS drugs were identified using Generic Product Identifier (GPI) codes for the National Drug Code (NDC) numbers on pharmacy claims. Mail order pharmacy claims with up to a 90-day supply were counted as 3 claims, and community pharmacy claims dispensed with up to a 34-day supply were counted as 1 claim. Self-injectable MS drugs were identified from medical claims using Healthcare Common Procedure Coding System (HCPCS) codes: J1595 for glatiramer, J1830 for subcutaneous interferon beta-1b, Q3026 for subcutaneous interferon beta-1a, and Q3025 and J1825 for intramuscular interferon beta-1a.


RESULTS
For the approximately 9 million members with data from pharmacy claims only, these 4 self-injectable MS drugs accounted for approximately 1.8% of total pharmacy benefit spending in 2004, 1.9% in 2005, 2.3% in 2006, and 2.4% in 2007. The mean average wholesale price (AWP) per member per month (PMPM) increased by 56.8%, from $1.11 PMPM in the first quarter of 2004 to $1.74 PMPM in the third quarter of 2007. Utilization was flat at about 82-83 claims per 100,000 members per month during the 45-month measurement period. The average annual price increase per unit ranged from 8.9% for interferon beta-1a to 13.3% per year for interferon beta-1b. Members paid a median out-of-pocket cost per pharmacy claim of $15 in 2004, $20 in 2005 and 2006, and $25 in the first 9 months of 2007. For the 1.8 million members with both pharmacy and medical benefit claims, the medical benefit accounted for 2.5% of total spending on MS self-injectables in 2004, 2.0% in 2005 and 2006, and 1.2% in 2007.


CONCLUSIONS
The percentage of all pharmacy expenditures that was attributable to self-injectable MS drugs increased from 1.8% in 2004 to 2.5% in 2007. Nearly all of the increase in spending on self-injectable MS drugs over the nearly 4-year period was attributable to drug price increases because PMPM utilization was essentially unchanged. The median member cost-share was approximately 1% of the total cost of self-injectable MS drugs.
Kunze
April M
AM
Prime Therapeutics, 1305 Corporate Center Drive, Eagan, MN 55121, USA. akunze@primetherapeutics.com
Gunderson
Brent W
BW
Gleason
Patrick P
PP
Heaton
Alan H H
AH
Johnson
Steven V
SV
D000911:Antibodies, Monoclonal / Q000191:economics / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized; D017047:Cost Sharing; D003669:Deductibles and Coinsurance / Q000191:economics / Q000639:trends; D016527:Drug Costs / Q000639:trends*; D004363:Drug Utilization / Q000191:economics / Q000706:statistics & numerical data / Q000639:trends*; D005252:Fees, Pharmaceutical / Q000706:statistics & numerical data / Q000639:trends*; D000068717:Glatiramer Acetate; D006801:Humans; D007166:Immunosuppressive Agents / Q000191:economics / Q000627:therapeutic use; D007250:Inflation, Economic; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D007370:Interferon Type I / Q000191:economics / Q000627:therapeutic use; D008942:Mitoxantrone / Q000191:economics / Q000627:therapeutic use; D009103:Multiple Sclerosis / Q000188:drug therapy* / Q000191:economics*; D000069442:Natalizumab; D010455:Peptides / Q000191:economics; D011994:Recombinant Proteins; D012646:Self Administration; D014481:United States
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D007166:Immunosuppressive Agents; D007370:Interferon Type I; D000069442:Natalizumab; D010455:Peptides; D011994:Recombinant Proteins; D000068717:Glatiramer Acetate; D008942:Mitoxantrone