Takhzyro costs $435,556 per patient per year, making it the most expensive drug in America by annual treatment cost. It treats hereditary angioedema, a rare genetic condition affecting roughly 6,000 to 10,000 Americans. Medicare Part D covers 512 of those patients.
That number sounds outrageous until you consider the scale: 255 drugs on Part D now cost over $100,000 per patient per year. Together they account for $91.5 billion in annual Medicare spending, up from $37.6 billion in 2020. Fewer than 653,000 patients take them.
TL;DR
- Takhzyro ($435K/year) and Acthar ($431K/year) are the two costliest drugs per patient
- 255 Part D drugs now exceed $100,000 per patient per year
- These ultra-expensive drugs consume 15.9% of all Part D spending but serve less than 1% of beneficiaries
- The $100K+ drug spending share grew from 9.7% (2020) to 15.9% (2024) in four years
- Most treat rare diseases (hereditary angioedema, cystic fibrosis, complement disorders) or refractory gout
- Trikafta (cystic fibrosis) is the largest by total spend at $724.7 million across 2,732 patients
How we ranked these drugs
Data source: CMS Medicare Part D Drug Spending Dashboard, 2024 data year (released June 2026).
Method: We divided total annual Medicare spending by total unique beneficiaries for each drug to calculate cost per patient per year. We filtered to drugs with 500 or more Medicare patients to exclude experimental outliers with tiny populations.
What this measures: The actual amount Medicare paid per person taking that drug in 2024, including all fills. A patient on Takhzyro averaged 9.3 fills per year at $46,929 each.
Limitation: These are Medicare (65+, disabled) costs. Commercial insurance pricing may differ. The per-patient figure includes all fills, so patients who started mid-year pull the average down slightly.
The 10 most expensive drugs by annual patient cost
| Rank | Brand Name | Generic Name | Annual Cost/Patient | Cost/Fill | Patients | Total Spend |
|---|---|---|---|---|---|---|
| 1 | Takhzyro | Lanadelumab | $435,556 | $46,929 | 512 | $223M |
| 2 | Acthar | Corticotropin | $430,690 | $73,093 | 836 | $360M |
| 3 | Gattex | Teduglutide | $371,761 | $50,478 | 962 | $358M |
| 4 | Ultomiris | Ravulizumab | $332,291 | $58,956 | 701 | $233M |
| 5 | Krystexxa | PEGloticase | $320,769 | $44,230 | 662 | $212M |
| 6 | Tepezza | Teprotumumab | $294,974 | $56,097 | 515 | $152M |
| 7 | Ayvakit | Avapritinib | $292,553 | $39,778 | 547 | $160M |
| 8 | Trikafta | Elexacaftor/Tezacaftor/Ivacaftor | $265,267 | $26,570 | 2,732 | $725M |
| 9 | Vyvgart | Efgartigimod | $254,275 | $49,425 | 947 | $241M |
| 10 | Cortrophin | Corticotropin | $217,770 | $61,425 | 596 | $130M |
Every drug on this list treats a condition with no cheaper alternative. That matters for understanding why payers cover them at these prices.
What each drug treats (and why it costs this much)
1. Takhzyro: $435,556/year
Takhzyro (lanadelumab) prevents attacks in hereditary angioedema (HAE), a condition where random severe swelling can close the airway. Patients inject it every two weeks. Before Takhzyro, HAE patients relied on on-demand treatments during attacks. The shift to prevention increased annual spending per patient but reduced emergency visits.
Takeda (formerly Dyax) has no generic competition. HAE affects roughly 1 in 50,000 people.
2. Acthar: $430,690/year
Acthar Gel (corticotropin) is the most controversial drug on this list. It treats infantile spasms, multiple sclerosis flares, and nephrotic syndrome. The active ingredient (ACTH) has existed since the 1950s. Mallinckrodt acquired the sole manufacturing rights and raised the price from $40 per vial in 2001 to over $40,000 per vial.
The 836 Medicare patients on Acthar average 5.9 fills per year at $73,093 each.
3. Gattex: $371,761/year
Gattex (teduglutide) treats short bowel syndrome, where patients cannot absorb enough nutrition from food because too much intestine was surgically removed. Without it, patients depend on intravenous feeding (TPN) that costs $150,000-$300,000 per year and carries serious infection risk.
Takeda markets Gattex as a way to reduce or eliminate TPN dependence. The 962 patients on it average 7.4 fills per year.
4. Ultomiris: $332,291/year
Ultomiris (ravulizumab) treats paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS), both ultra-rare complement disorders where the immune system destroys red blood cells. Alexion (now AstraZeneca) launched it as a longer-acting successor to Soliris, reducing infusion frequency from every two weeks to every eight weeks.
Patient count grew from 195 in 2022 to 701 in 2024 as patients switched from Soliris.
5. Krystexxa: $320,769/year
Krystexxa (pegloticase) treats chronic refractory gout, the subset of gout patients who fail all oral medications. These patients have uric acid crystal deposits (tophi) in their joints and tissues. Krystexxa is the only drug that can dissolve established tophi.
Horizon (now Amgen) has grown Krystexxa's patient base from 242 in 2020 to 662 in 2024 after adding immunomodulator co-treatment that improved response rates from 42% to 71%.
6. Tepezza: $294,974/year
Tepezza (teprotumumab) is the only drug approved for thyroid eye disease (TED), where the eyes bulge forward due to tissue swelling behind them. Before Tepezza, surgery was the only treatment. Patients receive 8 infusions over 24 weeks.
Horizon launched it in January 2020. The 515 Medicare patients represent a fraction of the TED population (most patients are under 65 and on commercial insurance).
7. Ayvakit: $292,553/year
Ayvakit (avapritinib) treats advanced systemic mastocytosis (AdvSM) and PDGFRA-mutant gastrointestinal stromal tumors (GIST). AdvSM is a blood cancer where mast cells accumulate in organs. Blueprint Medicines launched it in 2021 after FDA approval based on response rates above 50% in AdvSM.
The 547 patients average 7.4 fills per year at $39,778 each.
8. Trikafta: $265,267/year
Trikafta is the largest drug on this list by total spending ($724.7 million) and patient count (2,732). It treats cystic fibrosis by correcting the defective CFTR protein. Before Trikafta, median life expectancy for CF patients was the late 30s. Clinical trials showed FEV1 improvement of 14 percentage points and pulmonary exacerbation reduction of 63%.
Vertex Pharmaceuticals has no competition in the CFTR modulator space. Trikafta covers about 90% of CF genotypes.
9. Vyvgart: $254,275/year
Vyvgart (efgartigimod) treats generalized myasthenia gravis (gMG), an autoimmune condition that causes muscle weakness. It works by reducing the pathogenic IgG antibodies that attack the neuromuscular junction. Argenx launched it in 2022 and expanded to a subcutaneous version (Vyvgart Hytrulo) in 2023.
Combined, the two formulations cover 1,605 Medicare patients.
10. Cortrophin: $217,770/year
Cortrophin Gel is ANI Pharmaceuticals' version of the same corticotropin active ingredient as Acthar. It treats the same conditions (infantile spasms, MS flares, nephrotic syndrome) but entered the market in 2022 as a lower-priced competitor. "Lower-priced" is relative: it still costs $217,770 per patient per year.
The $100K+ drug spending explosion
The most alarming trend in this data is the growth rate. Drugs costing over $100,000 per patient per year now consume a steadily larger share of Medicare Part D:
| Year | $100K+ Drug Spending | Total Part D Spending | Share of Total |
|---|---|---|---|
| 2020 | $37.6B | $386.6B | 9.7% |
| 2021 | $49.2B | $425.0B | 11.6% |
| 2022 | $59.6B | $477.3B | 12.5% |
| 2023 | $67.6B | $549.2B | 12.3% |
| 2024 | $91.5B | $574.9B | 15.9% |
That is a 143% increase in ultra-expensive drug spending over four years, while total Part D spending grew 49%. The gap accelerated in 2024.
Two forces drive this:
- More patients gaining access (Krystexxa grew from 242 to 662 patients; Ultomiris from 195 to 701)
- New drugs launching at six-figure prices (Vyvgart did not exist before 2022)
"Most expensive" vs. "most costly to Medicare"
These are different rankings. The most expensive drug per patient (Takhzyro at $435K) costs Medicare $223 million total because only 512 patients take it. But Eliquis, at a modest $863 per fill, costs Medicare $20.8 billion because 4.4 million patients take it.
| Drug | Cost/Patient | Total Medicare Spend | Why |
|---|---|---|---|
| Takhzyro | $435,556 | $223M | Few patients, extreme price |
| Eliquis | $4,695 | $20,774M | Millions of patients, moderate price |
| Trikafta | $265,267 | $725M | Middle ground: rare disease, high price |
| Ozempic | $6,641 | $12,970M | Mass-market, premium brand price |
Policy debates swing between two camps: control per-unit prices (targeting Takhzyro) or control volume (targeting Eliquis and Ozempic). The Inflation Reduction Act's drug negotiation provisions focused on the high-volume drugs first. Rare disease drugs are largely exempt.
Why these drugs have no competition
Every drug in the top 10 shares at least one of these traits:
- Orphan drug designation. FDA gives 7 years of market exclusivity for drugs treating conditions affecting fewer than 200,000 Americans. Eight of the ten qualify.
- Biologic complexity. Seven are biologics (large proteins) rather than small molecules. Biosimilar development costs $100-$250 million and takes 8-10 years compared to $1-$5 million and 2-3 years for generic pills.
- Tiny addressable population. When your total market is 500-5,000 patients, you cannot spread R&D costs over millions of prescriptions. The math requires high per-unit prices.
- No therapeutic substitutes. Most have no alternative treatment at all (Takhzyro, Gattex, Tepezza) or only one competitor at a similar price (Ultomiris vs. Soliris).
How the Inflation Reduction Act affects these drugs
The IRA's Medicare drug price negotiation program initially targeted 10 high-spend drugs (Eliquis, Jardiance, Xarelto, Januvia, and others). These are all high-volume, not high-per-patient drugs.
Rare disease drugs face a different timeline:
- Small-molecule drugs: eligible for negotiation after 9 years of FDA approval
- Biologics: eligible after 13 years
Takhzyro (approved 2018) would not be eligible until 2031. Trikafta (approved 2019) until 2028. Ultomiris (approved 2018) until 2031.
Patient advocacy groups pushed for these longer windows specifically because rare disease drugs need more time to recoup R&D investment across tiny patient populations.
How to access this data
All figures in this analysis come from the CMS Medicare Part D Drug Spending Dashboard, a public dataset updated annually.
Direct access:
- CMS Data Portal: data.cms.gov/summary-statistics-on-use-and-payments/medicare-medicaid-spending-by-drug
- Download the full CSV (roughly 60,000 rows per year, one row per drug per brand name)
Via API: MyfitByte normalizes this data alongside FDA adverse events, recalls, provider data, and drug labels into a single queryable interface.
Want to query drug spending data alongside safety signals, prescriber patterns, and insurance coverage? Join the MyfitByte API waitlist.
FAQ
What is the most expensive drug in the world?
Hemgenix (etranacogene dezaparvovec) for hemophilia B holds the record at $3.5 million for a one-time gene therapy infusion. However, it does not appear in per-year rankings because it is a single treatment, not an ongoing prescription. For annual treatment costs, Takhzyro at $435,556/year is the highest among drugs with 500+ Medicare patients.
Why are rare disease drugs so expensive?
Manufacturers spread research and development costs across small patient populations. Developing a drug for 500 patients costs roughly the same as developing one for 5 million patients (Phase 1-3 trials, regulatory submission, manufacturing setup). With 10,000x fewer buyers, the per-unit price must be 10,000x higher to achieve the same return.
Does insurance cover these drugs?
Medicare Part D covers all 10 drugs on this list. The data shown here represents what Medicare actually paid. Patient out-of-pocket costs depend on their plan's specialty tier (typically 25-33% coinsurance) and whether they hit the catastrophic coverage threshold ($8,000 in 2024). After catastrophic coverage, patients pay 5% of drug costs.
Are any of these drugs available as generics?
None of the top 10 have generic or biosimilar alternatives available as of August 2026. Seven are biologics (Takhzyro, Gattex, Ultomiris, Krystexxa, Tepezza, Vyvgart, Cortrophin) protected by biologic exclusivity and patent estates. Trikafta has patent protection through 2037. Acthar's manufacturing exclusivity has prevented competition despite the underlying compound being decades old.
How many Medicare patients take drugs costing over $100K per year?
Approximately 653,000 Medicare beneficiaries take drugs costing over $100,000 per patient per year. They account for less than 1.5% of all Part D beneficiaries but 15.9% of total Part D spending ($91.5 billion of $574.9 billion in 2024).
Is drug spending growing faster than inflation?
Ultra-expensive drug spending ($100K+ per patient) grew 143% from 2020 to 2024. Total Part D spending grew 49% over the same period. General inflation (CPI) was approximately 22% over those four years. The growth is driven primarily by new drug launches and expanded patient access rather than price increases on existing drugs.
What is the Inflation Reduction Act doing about expensive drugs?
The IRA allows Medicare to negotiate prices on high-spend drugs, but rare disease drugs (most of this list) have longer protection periods: 9 years for small molecules, 13 years for biologics before they become negotiation-eligible. The first 10 negotiated drugs (effective 2026) are all high-volume drugs like Eliquis and Januvia, not rare disease specialty drugs.
Where does this data come from?
CMS (Centers for Medicare and Medicaid Services) publishes Medicare Part D Drug Spending data annually. The 2024 data year was released in June 2026. It covers all Part D claims (approximately 50 million beneficiaries). The dataset includes total spending, claims, beneficiary counts, and per-unit costs for every drug dispensed through Part D pharmacies.
Published on 2026-08-26 · 12 min read
← Back to all articles