Medicare Part D spending · FDA facts · help paying
Avonex (interferon beta-1a): what Medicare Part D spends and the dated federal facts we hold
CMS's Medicare Part D spending dataset lists Avonex under 2 names; the sum of their gross spending is $288.29 million in 2024, across 31,616 claims. The FDA's enforcement reports name this drug's packages in 1 recall entry.
Medicare Part D spending
CMS's Medicare Part D spending dataset lists Avonex under 2 names; the sum of their gross spending is $288.29 million in 2024, across 31,616 claims. CMS's dataset states spending is gross drug cost and does not reflect manufacturers' rebates or other price concessions. Spending is the total paid by Medicare, plans and beneficiaries for the drug's claims, not what a patient pays.
| Year | Gross spending | Claims |
|---|---|---|
| 2024 | $288.29 million | 31,616 |
| 2023 | $317.36 million | 35,197 |
| 2022 | $362.08 million | 42,359 |
| 2021 | $468.57 million | 56,073 |
| 2020 | $555.26 million | 66,077 |
Names CMS reports it under
| Name in the CMS file | Year | Gross spending | Claims |
|---|---|---|---|
| Avonex Pen (4 Pack) | 2024 | $161.33 million | 17,791 |
| Avonex (4 Pack) | 2024 | $126.96 million | 13,825 |
Source: CMS Medicare Part D spending by drug (data-year-2024, modified 2026-06-25), read November 7, 2026. CMS dataset page. All manufacturers combined; the figures are a drug-level aggregate of claims and say nothing about a formulary or coverage.
Biosimilar status
- Avonex (interferon beta-1a) is a reference product in the FDA Purple Book (BLA 103628, approved May 17, 1996). The Purple Book lists 0 biosimilars and 0 interchangeable products that name it as their reference product.
This is what the FDA Purple Book lists on the read date. It is a record, not a forecast of when any product will launch or be substituted.
Source: FDA Purple Book (purplebook-2026-10), read November 7, 2026. Purple Book data file.
Rare-disease (orphan) designations
The FDA's orphan drug database lists 3 designations for Interferon beta-1a; interferon Beta-1a, 1 with an approval recorded. A designation is not an approval and not a statement that the drug treats the condition; the status column is the database's own.
| Designated | Designated use | Status | Sponsor |
|---|---|---|---|
| October 14, 1998 | Treatment of juvenile rheumatoid arthritis. | Designated/Designation Withdrawn or Revoked | Biogen, Inc. |
| March 11, 1996 | Treatment of patients with secondary progressive multiple sclerosis | Designated/Designation Withdrawn or Revoked | EMD Serono, Inc. |
| December 16, 1991 | Treatment of multiple sclerosis. | Designated/Approved | Biogen, Inc. |
Source: FDA Orphan Drug Designations and Approvals database, read November 7, 2026. FDA orphan drug search.
Medicaid use by state
CMS's State Drug Utilization Data records, for 2025, how many prescriptions each state's Medicaid program paid for under this drug's packages and what it reimbursed. The 1 states with the largest reimbursement are shown. Reimbursement is before the rebates manufacturers pay states, so it is not a net cost and not a price a patient pays.
| State | Medicaid-paid prescriptions | Medicaid reimbursed | Covers |
|---|---|---|---|
| CA | 245 | $2,186,473 | All record types |
A state missing from the table means its figures were suppressed or not reported, not zero use. 31 older-year figures are held and left out of the table.
Source: CMS State Drug Utilization Data (State Drug Utilization Data 2025, modified 2026-07-13T15:28:32Z), read November 7, 2026. CMS dataset page. State-reported data compiled by CMS; aggregate by state and package, no provider or patient data.
Medicaid spending
CMS's Medicaid spending dataset reports $44.65 million for Avonex in 2024. CMS's dataset states spending includes Federal and State reimbursement and dispensing fees and is not reduced by Medicaid rebates paid to the states. Spending is what Medicaid paid, not what a patient pays.
| Year | Spending | Claims |
|---|---|---|
| 2024 | $44.65 million | 5,421 |
| 2023 | $57.81 million | 7,378 |
| 2022 | $62.00 million | 8,294 |
| 2021 | $70.68 million | 9,804 |
| 2020 | $78.95 million | 11,406 |
Source: CMS Medicaid spending by drug (data-year-2024, modified 2026-06-25), read November 7, 2026. CMS dataset page. A national drug-level aggregate; it says nothing about any state's coverage rules.
Federal formulary status
VA national formulary
The VA's national formulary files list the ingredient interferon beta-1a, which covers every maker's product with that ingredient, not only Avonex. Each row is a VA national drug file entry and its status.
| VA entry | Status | Active NDCs |
|---|---|---|
| INTERFERON BETA-1A INJ,SOLN | Mixed | 15 |
Source: VA Pharmacy Benefits Management national formulary (va-formulary-2026-09), read November 7, 2026. VA formulary page.
Where help paying exists
No program in our finder currently lists this drug as open to new patients.
Label changes
The FDA file lists no non-manufacturing label change for these applications since November 11, 2025. The most recent one it lists is dated July 28, 2023 (Labeling).
Source: FDA Drugs@FDA data file, read November 7, 2026. Dates are the FDA action dates; the documents are on FDA's own site. FDA data file. All recent changes across these drugs: label changes feed.
Safety notices
FDA enforcement report entries that name a package of Avonex by its NDC: 1 entry, newest first. FDA assigns each a class by health risk: Class I is the most serious and Class III the least. An entry records what the recalling firm reported and FDA classified; it is not advice about any package you hold.
| Reported | Class | Status | Recalling firm | Reason (shortened) | Packages named |
|---|---|---|---|---|---|
| May 16, 2018D-0776-2018 | Class II | Terminated | Kroger Specialty Pharmacy, Inc. | Lack of Processing Controls. | 1 |
Source: openFDA drug enforcement reports, file read November 7, 2026. openFDA data file. All recent recalls across these drugs: drug recalls feed.
Questions
Does Medicare have a negotiated price for Avonex?
The CMS negotiated-price file we read does not list Avonex, so this page shows no negotiated price. A drug appears in that file only when CMS selects it for negotiation, and not being listed says nothing about what it costs a patient.
Is there help paying for Avonex?
No program in our finder lists this drug yet.
How much does Medicare Part D spend on Avonex?
CMS's Medicare Part D spending dataset lists Avonex under 2 names; the sum of their gross spending is $288.29 million in 2024, across 31,616 claims. CMS's dataset states spending is gross drug cost and does not reflect manufacturers' rebates or other price concessions. Spending is the total paid by Medicare, plans and beneficiaries for the drug's claims, not what a patient pays.
For developers: this drug as data
One call returns the generic-entry upper bound, label history, recalls, trials, assistance and Part D spending, and where facts exist the FDA safety program (REMS), DEA schedule, orphan designations, safety notices and Medicaid use by state, each with receipts.
Example file: https://omnirx.org/api/v1/dossier/avonex.json
The licence page sets out what a data licence covers, and the API page documents these files.
Evaluation files with receipts; contract may change; not clinical advice.
Sources and terms. This drug is not in the CMS negotiated-price file, so no price source is used. Program details read from each program's own pages; CMS Medicare Part D spending by drug; CMS Medicaid spending by drug; TRICARE and VA formulary files; FDA Purple Book; FDA Drugs@FDA and Orange Book data files; openFDA drug enforcement reports. Figures are stored with their sources in the OmniRx library (edition 2026-11). Free to cite with attribution. Not medical, legal or financial advice. Report an error through the contact page. Licence the data.