Strensiq (Asfotase Alfa) — Medicare Part D spending
Alexion Pharmac · Rank #187 by total Part D spend · CMS data year 2023
Medicare Part D spent $258,940,106 on Strensiq (Asfotase Alfa) in 2023, the #187 drug by total Part D spending out of 3,598 drugs. That worked out to about $6,180.92 per dosage unit, $102,227 per claim and $1,250,918 per beneficiary, across 2,533 claims for 207 beneficiaries. Average spending per dosage unit fell -0.9% from 2022. These are aggregate Medicare program figures (gross drug cost), not the price you pay.
Source: CMS Medicare Part D Spending by Drug (data year 2023). Data as of June 2026.
Strensiq (Asfotase Alfa) spending at a glance (2023)
| Metric | Strensiq (Asfotase Alfa) |
|---|---|
| Total Part D spending (2023) | $258,940,106 |
| Total spending (2022) | $220,781,958 |
| Year-over-year change in total spending | +17.3% |
| Average spending per dosage unit (2023) | $6,180.92 |
| Change in spend per dosage unit (YoY) | -0.9% |
| Avg annual change per dosage unit (2019-2023 CAGR) | -0.1% |
| Average spending per claim (2023) | $102,227 |
| Average spending per beneficiary (2023) | $1,250,918 |
| Total claims (2023) | 2,533 |
| Beneficiaries (2023) | 207 |
| Total dosage units (2023) | 39,383 |
| Manufacturer(s) | Alexion Pharmac |
| National rank by total spend (of 3,598 drugs) | #187 |
Source: CMS Medicare Part D Spending by Drug (data year 2023). Data as of June 2026.
2022 vs 2023
| Metric | 2022 | 2023 | Change |
|---|---|---|---|
| Total spending | $220,781,958 | $258,940,106 | +17.3% |
| Avg spend per dosage unit | $6,238.68 | $6,180.92 | -0.9% |
| Avg spend per claim | $102,451 | $102,227 | — |
| Avg spend per beneficiary | $1,322,048 | $1,250,918 | — |
| Total claims | 2,155 | 2,533 | — |
| Beneficiaries | 167 | 207 | — |
How Strensiq compares with nearby drugs
Drugs with total Part D spending closest to Strensiq (Asfotase Alfa):
| Drug (rank) | Total spend 2023 | Per dosage unit | Per-unit YoY |
|---|---|---|---|
| Strensiq (Asfotase Alfa) (this drug, #187) | $258,940,106 | $6,180.92 | -0.9% |
| Oxycodone-Acetaminophen (Oxycodone HCl/Acetaminophen) (#185) | $263,023,627 | $0.37 | +5.5% |
| Nucala (Mepolizumab) (#186) | $260,986,344 | $3,769.30 | +8.8% |
| Humira (Adalimumab) (#188) | $257,644,313 | $3,568.20 | +11.4% |
| Cyclosporine* (Cyclosporine) (#189) | $255,901,494 | $5.66 | -14.4% |
| Xolair (Omalizumab) (#190) | $254,056,609 | $1,363.73 | +7.7% |
Frequently asked questions
How much does Medicare Part D spend on Strensiq?
Medicare Part D spent $258,940,106 on Strensiq (Asfotase Alfa) in 2023 (the latest CMS data year), across 2,533 claims for 207 beneficiaries. That ranks #187 of 3,598 drugs by total Part D spending. This is gross drug cost (Medicare, plan and beneficiary payments combined), not the price you personally pay.
What is the average spending per dosage unit for Strensiq?
In 2023, the weighted average Medicare Part D spending per dosage unit for Strensiq (Asfotase Alfa) was $6,180.92. Compared with 2022 it fell -0.9%. A "dosage unit" is one pill, tablet, milliliter or other billing unit, so this is not the price of a prescription.
Who makes Strensiq?
CMS attributes Strensiq (Asfotase Alfa) to Alexion Pharmac in the 2023 Part D spending file. Average spending per claim was $102,227 and per beneficiary $1,250,918.
Is the Strensiq figure the price I pay?
No. These are aggregate Medicare Part D program figures (total gross drug cost and averages across all claims), published by CMS for transparency. Your out-of-pocket cost depends on your plan, formulary, deductible and coverage phase. Always check your plan and talk to your pharmacist or doctor.
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Source & what this means
Figures are from the CMS Medicare Part D Spending by Drug dataset (data year 2023, US public domain). "Total spending" is the gross drug cost — Medicare, plan and beneficiary payments combined — for Part D claims; it is not a list price, a negotiated price, or what any individual pays. Spending per dosage unit is volume-weighted across formulations. This is general public-spending information, not medical or pricing advice. Your own cost depends on your plan, deductible and coverage phase — verify with your Part D plan and a pharmacist. Data as of June 2026. See our methodology and disclaimer.
Last updated: 2026-06-20