Out-of-Pocket Costs for Infliximab and Its Biosimilar for Rheumatoid Arthritis Under Medicare Part D | Clinical Pharmacy and Pharmacology | JAMA | JAMA Network
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Figure.  Standard Cost-Sharing Structure of Medicare Part D Drug Benefits in 2017
Standard Cost-Sharing Structure of Medicare Part D Drug Benefits in 2017

Adapted with permission from Kaiser Family Foundation Medicare Part D Prescription Drug Benefit.

aIn our analyses, patients’ out-of-pocket costs were based on average cost-sharing requirements for each drug across all Part D plans nationwide.

bManufacturer discount counts as out-of-pocket cost to reach catastrophic coverage threshold.

Table.  2017 Medicare Part D Plan Coverage and Cost-Sharing for Infliximab-dyyb (Biosimilar) and Infliximab (Biologic) (N = 2547 Plans)
2017 Medicare Part D Plan Coverage and Cost-Sharing for Infliximab-dyyb (Biosimilar) and Infliximab (Biologic) (N = 2547 Plans)
1.
Mulcahy  AW, Hlavka  JP, Case  SR.  Biosimilar cost savings in the United States: initial experience and future potential. https://www.rand.org/pubs/perspectives/PE264.html. Accessed April 9, 2018.
2.
Centers for Medicare & Medicaid Services.  2015 Medicare drug spending dashboard. https://www.cms.gov/Research-Statistics-Data-and-Systems/Statistics-Trends-and-Reports/Information-on-Prescription-Drugs/2015Medicare.html. Accessed April 9, 2018.
3.
Yazdany  J, Dudley  RA, Chen  R, Lin  GA, Tseng  CW.  Coverage for high-cost specialty drugs for rheumatoid arthritis in Medicare Part D.  Arthritis Rheumatol. 2015;67(6):1474-1480. doi:10.1002/art.39079PubMedGoogle ScholarCrossref
4.
Hakim  A, Ross  JS.  Obstacles to the adoption of biosimilars for chronic diseases.  JAMA. 2017;317(21):2163-2164. doi:10.1001/jama.2017.5202PubMedGoogle ScholarCrossref
5.
Kaiser Family Foundation.  The Medicare Part D prescription drug benefit. https://www.kff.org/medicare/fact-sheet/the-medicare-prescription-drug-benefit-fact-sheet/. Accessed April 9, 2018.
6.
Cubanski  J.  Summary of recent and proposed changes to Medicare prescription drug coverage and reimbursement. https://www.kff.org/medicare/issue-brief/summary-of-recent-and-proposed-changes-to-medicare-prescription-drug-coverage-and-reimbursement/. Accessed April 9, 2018.
Research Letter
September 4, 2018

Out-of-Pocket Costs for Infliximab and Its Biosimilar for Rheumatoid Arthritis Under Medicare Part D

Author Affiliations
  • 1Division of Rheumatology, University of California, San Francisco
  • 2Center for Healthcare Value, University of California, San Francisco
  • 3Pacific Health Research and Education Institute, Honolulu, Hawaii
  • 4Department of Family Practice and Community Health, University of Hawaii, Honolulu
JAMA. 2018;320(9):931-933. doi:10.1001/jama.2018.7316

Biologic specialty drugs are effective for treating rheumatic diseases, cancer, and other conditions. They represent approximately 2% of prescriptions but accounted for 38% of US drug spending in 2015 and 70% of drug spending growth between 2010 and 2015.1 For rheumatoid arthritis (RA), biologics cost more than $14 000 annually and 3 RA biologics were among the top 15 drugs by Medicare expenditures in 2015.2

In 2010, Congress empowered the US Food and Drug Administration to approve “biosimilars” of biologics to increase competition and lower cost. However, for the more than 43 million beneficiaries with Medicare Part D drug benefits, it is unclear whether biosimilars lower out-of-pocket costs given Part D’s complex cost-sharing structure.3-5 Part D consists of a deductible, coverage phase, coverage gap, and catastrophic coverage (Figure).5 When beneficiaries’ total drug costs exceed a set threshold, they enter the coverage gap and cost-sharing increases. Currently, beneficiaries receive a 50% manufacturer discount during the gap for brand-name drugs and biologics, but not for biosimilars.5 Although the recent Bipartisan Budget Act requires gap discounts for biosimilars starting in 2019, patients’ out-of-pocket costs will continue to depend on whether biosimilars differ from biologics in drug pricing and plan cost-sharing requirements.6 We examined coverage and cost-sharing for the first RA biosimilar (infliximab-dyyb) released in 2016 compared with its biologic (infliximab).

Methods

We analyzed nationwide benefit design data for all Part D plans from the June 2017 Medicare Prescription Drug Plan Formulary, Pharmacy Network, and Pricing Information Files to calculate mean total cost and out-of-pocket cost requirements for infliximab-dyyb and infliximab assuming a standard 8-week dosing regimen (6.5 prescriptions/y).3 We used these national means to project maximum annual out-of-pocket costs if beneficiaries used each drug and no other prescriptions under a standard 2017 Part D benefit, including a $400 deductible, coverage phase (out-of-pocket costs based on calculated national means), coverage gap starting at $3700 in total drug costs, and catastrophic coverage once out-of-pocket costs exceed $4950 (beneficiaries pay 5% for biologics or biosimilars thereafter). During the gap, beneficiaries pay 40% for biologics (plans pay 10%, manufacturer discounts 50%) and 51% for biosimilars (plans pay 49%).3,4 SAS (SAS Institute), version 9.4, was used to calculate means.

Results

Among 2547 plans, fewer plans covered infliximab-dyyb (10%) than infliximab (96%). Infliximab-dyyb had modestly lower mean total cost per 8-week prescription ($2185 vs $2667) and annually ($14 202 vs $17 335). However, plans universally required coinsurance cost-sharing for infliximab-dyyb, and set coinsurance rates similar to infliximab (26.6% vs 28.4% of drug cost, respectively) (Table). Without gap discounts, projected annual out-of-pocket costs were higher for infliximab-dyyb than infliximab ($5118 vs $3432).

Discussion

Nationwide under Medicare Part D, RA biosimilar infliximab-dyyb was only moderately less expensive (18% less) than biologic infliximab and exceeded $14000 annually. Without biosimilar gap discounts in 2017, beneficiaries would have paid more than $5100 for infliximab-dyyb or nearly $1700 more in projected out-of-pocket costs than infliximab. Study limitations include calculating mean costs unweighted by plan enrollment, and projecting annual out-of-pocket costs assuming use of a biologic or biosimilar and no other prescriptions. Although biosimilar gap discounts begin in 2019, infliximab-dyyb may still not significantly reduce Part D beneficiaries’ out-of-pocket costs given its high price and coinsurance cost-sharing similar to infliximab.6 Further policies are needed to address affordability and access to specialty drugs.

Section Editor: Jody W. Zylke, MD, Deputy Editor.
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Article Information

Accepted for Publication: May 10, 2018.

Corresponding Author: Jinoos Yazdany, MD, MPH, Division of Rheumatology, University of California, San Francisco, 1001 Potrero Ave, Building 30, San Francisco, CA 94110 (jinoos.yazdany@ucsf.edu).

Author Contributions: Drs Tseng and Chen had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Yazdany, Dudley, Tseng.

Acquisition, analysis, or interpretation of data: Lin, Tseng.

Drafting of the manuscript: Yazdany, Dudley, Tseng.

Critical revision of the manuscript for important intellectual content: All authors.

Statistical analysis: Chen, Tseng.

Obtained funding: Tseng.

Administrative, technical, or material support: Yazdany, Tseng.

Supervision: Tseng.

Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Yazdany has received an independent investigator award from Pfizer. No other disclosures were reported.

Funding/Support: This study was funded by grant R03HS016772 from the Agency for Healthcare Research and Quality (Dr Tseng), grant NIH/NIAMS P30 AR070155 from the Robert L. Kroc Endowed Chair in Rheumatic and Connective Tissue Diseases (Dr Yazdany), the Hawaii Medical Services Association Endowed Chair in Health Services and Quality Research at the University of Hawaii (Dr Tseng), and the Russell/Engleman Medical Research Center for Arthritis at the University of California, San Francisco (Dr Yazdany).

Role of the Funder/Sponsor: The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Disclaimer: The content is solely the responsibility of the authors and does not necessarily represent the official views of the Agency for Healthcare Research and Quality or the National Institutes of Health.

References
1.
Mulcahy  AW, Hlavka  JP, Case  SR.  Biosimilar cost savings in the United States: initial experience and future potential. https://www.rand.org/pubs/perspectives/PE264.html. Accessed April 9, 2018.
2.
Centers for Medicare & Medicaid Services.  2015 Medicare drug spending dashboard. https://www.cms.gov/Research-Statistics-Data-and-Systems/Statistics-Trends-and-Reports/Information-on-Prescription-Drugs/2015Medicare.html. Accessed April 9, 2018.
3.
Yazdany  J, Dudley  RA, Chen  R, Lin  GA, Tseng  CW.  Coverage for high-cost specialty drugs for rheumatoid arthritis in Medicare Part D.  Arthritis Rheumatol. 2015;67(6):1474-1480. doi:10.1002/art.39079PubMedGoogle ScholarCrossref
4.
Hakim  A, Ross  JS.  Obstacles to the adoption of biosimilars for chronic diseases.  JAMA. 2017;317(21):2163-2164. doi:10.1001/jama.2017.5202PubMedGoogle ScholarCrossref
5.
Kaiser Family Foundation.  The Medicare Part D prescription drug benefit. https://www.kff.org/medicare/fact-sheet/the-medicare-prescription-drug-benefit-fact-sheet/. Accessed April 9, 2018.
6.
Cubanski  J.  Summary of recent and proposed changes to Medicare prescription drug coverage and reimbursement. https://www.kff.org/medicare/issue-brief/summary-of-recent-and-proposed-changes-to-medicare-prescription-drug-coverage-and-reimbursement/. Accessed April 9, 2018.
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