Daybue Generic: When Will Generic Trofinetide Be Available?
This page is aggregated from FDA records, court filings and company announcements. Coded and designed by Dr. Brian Staiger, PharmD, BCPS
Updated October 9, 2026 How we build our data
Daybue Generic at a Glance
Four quick answers from FDA records and our estimate.
- When is the first generic expected? 2038 to 2039 A wide window Why then?
- Has the FDA approved a generic? Not yet None in the FDA’s records yet Why not yet?
- When does the last patent end? January 2043 4 patents listed with the FDA Why is a generic expected sooner?
- Can you buy a generic today? Not yet No company lists one for sale
Generic trofinetide is expected to be available between 2038 and 2039. None is for sale yet.
Why 2038 to 2039?
The patent fight is likely to end in an agreement that sets the launch. The terms are not public yet. We rate it toss-up: still unsettled. Just as likely to slip as to hold.
If Daybue’s last patent runs to January 2043, how can a generic come sooner?
The 3 patents that run past the expected month, to January 2043 (11,370,755, 11,827,600 and 12,492,167), cover the active ingredient, the product’s formulation and a way of using it. A generic can still come sooner if a court rules a patent invalid or not infringed, or if the companies settle on an earlier date. Here, the companies are expected to settle on a date. That is why the expected month comes before the last protection ends. See the road to a generic
Why hasn’t the FDA approved a generic yet?
That is normal before a launch. The FDA usually can’t give a generic its final approval while a patent or exclusivity still blocks it, so final approval often comes close to the day the generic can be sold. No company holds a “tentative” approval yet either (the FDA’s word for a generic that is ready but still blocked).
Will the generic cost less?
Usually, but no company is recorded as having applied to make one yet, and a single company usually brings only a modest drop. See the price pattern
What should I do now?
Keep taking Daybue as prescribed. When a generic arrives, your pharmacy may switch you to it automatically, and it may look different. What a generic means for you
Our month is only an estimate based on available information, so we never name a day.
Daybue by the Numbers
- Reason
- Settlement expectedThe patent fight is likely to end in an agreement that sets the launch. The terms are not public yet.
- How sure
- Toss-up Still unsettled. Just as likely to slip as to hold.
- Price competition
- None filed yet No filers on record
- Brand sales
- $508M a yearBig seller
- FDA approved 2023 March 2023 FDA Orange Book
- Patents listed 4 last runs to January 2043 A generic is expected sooner, between 2038 and 2039. See why FDA Orange Book
- Medicare Part D spent $47.8M in 2025, for 112 people CMS Part D Spending by Drug
- Medicaid prescriptions 4,635 in the last four reported quarters, $220.9M CMS Medicaid drug utilization, to Q1 2026
Daybue’s Road to a Generic
Daybue has had the market to itself since the FDA approved it in March 2023 (Acadia Pharmaceuticals Inc). Its FDA protection (pediatric) runs to September 2030. Its 4 listed patents run to January 2043.
The first generic of Daybue is expected between 2038 and 2039.
Why that month: the patent fight is likely to end in an agreement that sets the launch. The terms are not public yet.
Why a Generic Can Come Before January 2043
The last listed patent runs to January 2043; a court ruling or a settlement can bring a generic sooner. Dr. Brian explains
Each bar runs from the brand’s approval to the day that protection ends. The green band is our projection for the first generic: a month, never a day, because legal dates move and a generic reaches shelves days to weeks after it is allowed. Sources: FDA Orange Book; the expected month from court records and company announcements.
Daybue Patents and FDA Protections
Every patent and exclusivity the FDA Orange Book lists for Daybue’s own applications. A protection running past the expected month does not mean the date is wrong: a settlement or a court ruling can let a generic in before a patent ends, and a patent on one formulation or use does not block every generic.
| Patent | What it covers | Protects until | Status |
|---|---|---|---|
| 9,212,204 | A way of using it (U-3556) | July 2032 with the pediatric extension | Active |
| 11,370,755 | The active ingredient; the product’s formulation | February 2041 with the pediatric extension | Active |
| 11,827,600 | The active ingredient; the product’s formulation; a way of using it (U-3556) | January 2043 with the pediatric extension | Active |
| 12,492,167 | The active ingredient; the product’s formulation; a way of using it (U-3556) | January 2043 with the pediatric extension | Active |
| Exclusivity | What it means | Ends | Status |
|---|---|---|---|
| New chemical entity NCE | Five years of protection for a medicine whose active ingredient the FDA had never approved before. | March 2028 | Active |
| Orphan drug ODE-425 | Seven years of protection for a use in a rare disease. | March 2030 | Active |
| Pediatric PED | Six more months, earned by studying the medicine in children. | September 2030 | Active |
Source: FDA Orange Book, application 217026. Patent numbers open the patent on Google Patents.
Who Is Lined Up to Make Generic Trofinetide
Three steps stand between a brand and a generic you can buy: a company applies to the FDA, the FDA approves it, and the company starts selling it.
Applied to the FDA
No company is recorded as having applied to the FDA to make a generic Daybue yet.
Approved by the FDA
Not yet. The FDA has not approved a generic trofinetide. Final approval often comes close to the day a generic can be sold.
For Sale in Pharmacies
Not yet. No company lists a generic trofinetide for sale with the FDA.
Sources: how many companies have applied, from court records and company announcements; approved generics from the FDA Orange Book; tentative approvals from Drugs@FDA; what is for sale from the FDA NDC Directory. The FDA does not disclose an application before it approves it (21 CFR 314.430).
Daybue Price: What Pharmacies Pay and What Generics Usually Do
What a Generic Could Cost
How we estimate it. The national survey of what pharmacies pay (NADAC) has no recent price for Daybue, so we cannot show dollars. Here is the FDA’s finding of how far the price pharmacies pay usually falls as generic companies join: about 31% with one company, 44% with two, 73% with four and over 95% with six or more (the typical drop for every drug whose first generic came out from 2015 to 2017).
Median prices pharmacies paid for the generic (invoice prices), compared with the brand’s price before generic entry, from FDA’s 2019 analysis “Generic Competition and Drug Prices”. At the manufacturer’s price FDA found steeper drops (about 39%, 54%, 79% and over 95%), the figures quoted elsewhere on this tracker. A typical pattern, not a price quote for this medicine.
What Medicare and Medicaid Spend on Daybue
Big public spending is part of why generic makers line up for a medicine, and why its first generic matters beyond the pharmacy counter. Figures are before manufacturer rebates, which are confidential.
Medicare Part D Spending
What Medicare drug plans spent on Daybue, before manufacturer rebates.
- $12.4M
- January to March 2026, the latest CMS has posted
For 84 people, about $61,525 per prescription fill - $47.8M
- 2025, the whole year
For 112 people, about $59,619 per prescription fill
See the numbers
| Period | Spending | People | Per fill |
|---|---|---|---|
| January to March 2026 | $12,366,611 | 84 | $61,525.43 |
| 2025 | $47,814,717 | 112 | $59,619.35 |
Source: CMS Medicare Part D Spending by Drug, matched by the brand name Daybue only, so no generic is counted in it. What CMS says it is used for: This medication is used to treat a certain rare genetic disorder (Rett syndrome). This disorder affects the development of the brain.
Medicaid Prescriptions by Quarter
4,635 prescriptions in the four quarters to Q1 2026, $220.9M paid.
See the numbers
| Quarter | Prescriptions | Medicaid paid |
|---|---|---|
| Q1 2026 | 1,129 | $53,899,779 |
| Q4 2025 | 1,160 | $55,065,119 |
| Q3 2025 | 1,176 | $56,303,686 |
| Q2 2025 | 1,170 | $55,626,603 |
| Q1 2025 | 1,193 | $56,504,616 |
Source: CMS Medicaid State Drug Utilization Data, over Daybue’s own package codes.
Daybue Strengths and Forms
| Strength | Form | How it is taken | Approved | Status |
|---|---|---|---|---|
| 200MG/ML | Solution | Oral | March 2023 | Prescription reference product |
Source: FDA Orange Book, Acadia Pharmaceuticals Inc. Listed for sale today by Acadia Pharmaceuticals Inc. (FDA NDC Directory).
Daybue NDC Codes and Packages
Each Daybue package sold today has its own NDC, the product number printed on the box and on the pharmacy label. Open one to see that package’s details, what pharmacies pay for it and its patent timeline.
| NDC | Product | Package | Company |
|---|---|---|---|
| 63090-0660-01 | TROFINETIDE 200 mg/mL solution | bottle of 450 mL | Acadia Pharmaceuticals Inc. |
| 63090-0660-01 | TROFINETIDE 200 mg/mL solution | bottle of 450 mL | Acadia Pharmaceuticals Inc. |
Source: the FDA NDC Directory, current listings only. Only packages sold under Daybue’s own FDA approval (NDA 217026) are listed, never a generic. Some codes belong to companies that repackage Daybue: it is the same medicine in a different package.
What a Generic Daybue Means for You
Nothing Changes Until It Is in Pharmacies
Until a generic is actually for sale, keep filling Daybue as usual. When one arrives, there is nothing you need to sign up for.
Your Pharmacy May Switch You Automatically
Every state lets pharmacists fill a brand-name prescription with an FDA-approved generic rated as equivalent to it, and about 19 states require them to, unless your prescriber writes “dispense as written” or “brand medically necessary” on the prescription. Some states ask the pharmacist to tell you, or to get your OK first. A study of every state’s law has the details.
It Will Probably Look Different
US trademark law does not let a generic look exactly like the brand, so the color, shape or markings usually change. The active ingredient, strength and form are the same. An “authorized generic,” made by or for the brand’s own company, can look identical. The FDA explains.
Your Insurance May Change Too
Once a lower-cost version is available, many insurance plans charge more for the brand, or stop covering it. Your plan’s drug list (formulary) says how.
Until a generic is on US pharmacy shelves, be careful with websites that offer “generic Daybue”. The FDA warns that unlicensed online pharmacies sell counterfeit and unapproved medicines; its BeSafeRx page shows how to check a pharmacy.
Questions people ask about Daybue
Is there a generic for Daybue right now?
No. As of October 9, 2026 no generic trofinetide is listed for sale in the FDA NDC Directory.
When will Daybue go generic?
2038 to 2039 is the expected window, and that is toss-up but not certain. The patent fight is likely to end in an agreement that sets the launch. The terms are not public yet. The last listed patent runs to January 2043; a court ruling or a settlement can bring a generic sooner.
Will generic trofinetide be the same as Daybue?
Yes in the ways that matter: the same active ingredient, strength and form, with proof that it reaches your blood the same way. Inactive ingredients can differ, which is why some people notice a different look or taste.
How much will the generic cost?
Nobody can say for sure before launch. No company is recorded as having applied to the FDA to make one yet, and a single company usually brings only a modest drop.
Has the FDA approved a generic Daybue?
Not yet. The FDA Orange Book lists no approved generic version of Daybue.
When does the Daybue patent expire?
The FDA Orange Book lists 4 patents for Daybue; the last runs to January 2043, counting a six-month pediatric extension. A patent date is not the launch date: settlements and court rulings often bring a generic earlier, and FDA approval or a company’s own plans can make it later. The expected window on this page (2038 to 2039) weighs all of that.
Changes to This Projection
- First generic expected 2038 to 2039 on this month’s schedule. A line is added here whenever a monthly update moves the month, the reason or how sure it is.
Every change to the expected month is logged here with the month we saw it.
Also Going Generic
- BendekaBendamustine HydrochlorideJanuary 2029
- ExxuaGepirone HydrochlorideSeptember 2030
- TarpeyoBudesonideDecember 2030
- PemfexyPemetrexedFebruary 2036
- LazcluzeLazertinib MesylateAugust 2041
- XocovaEnsitrelvir Fumaric Acid2042 to 2043
About Daybue
- Generic name trofinetide
- How it is taken By mouth
- Company Acadia Pharmaceuticals Inc
- More drugs Brand-name drugs starting with D
- Have a question? A pharmacist answers, free. Ask about Daybue
Sources. The expected month: FDA Paragraph IV Patent Certifications list, federal court records, company announcements and securities filings (settlement dates, launch plans, sales). The record on this page: FDA Orange Book, Drugs@FDA (tentative approvals), FDA NDC Directory, CMS Medicare Part D Spending by Drug, Medicaid State Drug Utilization Data, FDA, Generic Competition and Drug Prices (2019). Updated October 9, 2026. Information, not medical advice.