Three Orange Book patent dates fall within 16 days of each other this November. Entresto’s first listed patent expires on November 8, 2026. Eliquis’s first listed patent expires on November 21, 2026. Januvia’s sitagliptin salt patent expires on November 24, 2026. [1][3]
A model that keys on those dates predicts three generic launches. The real result is different. MSN launched generic Entresto in July 2025, about 15 months before its date. [10] Generic Januvia launched in May 2026, six months before its date. [4][10] Generic Eliquis cannot launch before April 1, 2028, 497 days after its date. [5][6]
The Orange Book date is one input. The date your model is missing belongs to a named company. It is the date that company can lawfully and practically ship a product. This article calls it the filer-level entry date. A drug has one such date for each filer, and the brand loses exclusivity on the earliest one.
The sections below define the date, test it against five documented products, and show how to add it to a forecast. DrugPatentWatch has published related analyses of this problem. [1][2] This article adds a different test: how wrong is a single-date model, and in which direction?
The Short Answer: Which Date Is Your Model Missing?
The missing date is the filer-level entry date. It is the latest barrier that applies to one named generic or biosimilar company. A model needs one such date per filer, not one expiry date per drug.
What Is the Filer-Level Entry Date?
The filer-level entry date is the earliest day a named company can sell its product in the United States. Every legal, regulatory, contractual, and supply barrier that applies to that company must have ended. DrugPatentWatch uses a close idea, the binding clock, which it defines as the clock that blocks a given launch for the longest time. [1] This article adds one step. A brand drug loses exclusivity on the earliest filer-level date, so the brand-level date is a minimum of maximums. Section 11 shows the formula.
The Five Findings That Matter
In five documented product cases, entry came before the reference Orange Book date four times and after it once. (Calculated.)
The gap ranges from 971 days early to 497 days late. The mean absolute gap is 515 days. (Calculated.)
Because the sign changes, no fixed “add N months” correction fixes a one-date model.
One drug can carry several entry dates. Revlimid had a volume-limited license from March 2022 and unlimited licenses from January 31, 2026. [9][6]
Each added entrant changes price. FDA found median generic prices 38.6 percent below brand price with one generic maker and 78.8 percent below with four. [12]
Methodology: How We Compared Orange Book Dates With Entry Dates
This section lists the data, the selection rule, the calculation, and the limits. A reader can repeat the work with the same sources.
What Data We Used and How We Picked Records
We used five products: Eliquis, Entresto, Januvia, Janumet, and Revlimid. We picked them because company filings, court records, or press releases give a documented entry date. We also describe Pomalyst, Xarelto, and Humira, but we did not put them in the gap table. They lack a verified Orange Book reference date in our sources.
Entry dates come from company SEC filings, company press releases, and trade reports of court events. [4][5][6][9] Orange Book reference dates come from DrugPatentWatch analyses that cite FDA Orange Book pages retrieved on October 16, 2026. [1][2] The Januvia and Janumet patent dates come from Merck’s press release. [3] We did not pull the Orange Book again for this article. Check the live FDA database before you rely on any date.
How We Calculated the Gaps
We counted calendar days from the reference Orange Book date to the entry date. A negative number means entry came before the patent date. A positive number means entry came after it. We computed the mean and median of the absolute values. Every gap in this article is our calculation. No source reports these gaps as independent statistics.
Limits of This Analysis
The case set is small and selected. We chose products where the patent date and the entry date differ, because those are the cases that break forecasts. The set cannot tell you how often the Orange Book date is wrong across all drugs. Some products have more than one listed patent, and the “reference” date is the one the sources name. Dates marked “expected” are not confirmed events.
Definitions: Patent Expiry, Loss of Exclusivity, and Filer-Level Entry Date
Orange Book Patent Expiration Date
An Orange Book patent expiration date is the date a listed patent ends, as the brand company reported it to FDA. It is one legal fact about one patent. It does not say who can launch or when.
Loss of Exclusivity (LOE)
Loss of exclusivity is the date the first generic or biosimilar product reaches the market. Analysts use it to start the revenue decline. LOE depends on every barrier to entry, not only on patents.
Filer-Level Entry Date (Original Definition)
This is our working term, not an FDA term and not an industry standard. It is the earliest date a named company can ship its product. We write it as d(f), where f is the filer. A model that stores only one date per drug cannot hold d(f).
What Does the Orange Book Date Show, and What Does It Miss?
The Orange Book date shows the end of one patent. It misses contracts, court orders, exclusivities that run apart from patents, and each filer’s readiness.
Who Decides What Appears in the Orange Book?
The brand company submits patent information to FDA, and FDA lists it. FDA does not decide whether a listed patent is valid or infringed. Federal law sets the listing rules. [13] A listed patent can start a 30-month stay when a generic filer challenges it. [13] A model that reads the list as a calendar of legal blocks treats a filing as a ruling.
How Pediatric Exclusivity Moves the Date by Six Months
Pediatric exclusivity adds six months to the protection that already exists. [15] A database that shows the raw patent date can understate protection by half a year. Two cases show the effect.
Entresto: An Expired Patent That Still Blocked a Launch
Novartis’s US 8,101,659 patent had expired, but pediatric exclusivity extended it to July 15, 2025. [8] In April 2025 the Delaware court ordered FDA to reset MSN’s effective approval date to no earlier than July 16, 2025. [8] Generic Entresto launched on July 22, 2025. [10] That is seven days after the pediatric date.
Januvia: Six Months Past the Salt Patent
Merck’s sitagliptin salt patent, US 7,326,708, expires on November 24, 2026. Pediatric exclusivity extends it to May 24, 2027. [3] A model that uses only the first date is 181 days short of the pediatric date. (Calculated.)
Why One Drug Has Several Orange Book Dates
A product can list patents for the compound, the salt, the formulation, and the combination. Merck lists a co-formulation patent, US 8,414,921, for Janumet. It expires on January 21, 2029, with pediatric exclusivity to July 21, 2029. [3] Janumet generics still entered in May 2026 under settlements. [4] The model must choose which listed date matters, and the choice changes the answer by years.
FDA and Patent Clocks That Run Apart From the Listed Patent
Four statutory mechanisms can move a generic entry date away from a listed patent date. A model that reads only the patent column misses each of them.
How Does a 30-Month Stay Delay Final Approval?
When a generic filer certifies that a listed patent is invalid or not infringed, the brand can sue within 45 days. That suit triggers a stay that blocks final FDA approval of the generic for up to 30 months. [13] The stay is a litigation clock. It can end earlier if a court rules for the filer, and it can pass without a ruling.
What Are NCE Exclusivity and the NCE-1 Date?
A new chemical entity gets five years of regulatory exclusivity. A generic company may file an application after four years if it challenges a listed patent. In that case the 30-month stay runs to 7.5 years from approval. [13] This clock starts at the brand’s FDA approval and does not depend on any patent.
How Does 180-Day First-Filer Exclusivity Work?
The first generic applicant to challenge a listed patent can receive 180 days of exclusivity against later generic applicants. [13] During those days the market has few generic makers. The FDA price data in this article show why that matters: one generic maker brings a median price cut of 38.6 percent, not 78.8 percent. [12] The date the 180 days end is a second date that a model should carry.
How Much Can a Patent Term Extension Add?
A patent term extension restores some time lost to FDA review. The extension is capped at five years, and the patent cannot run more than 14 years past approval. Only one patent per product can receive an extension. [16] The listed date for that patent normally reflects the extension. The dates for the product’s other patents do not.
Table: Five Products, One Reference Date Each, Calculated Gaps
The table compares the reference patent date with the documented entry date. Gaps are our calculations in calendar days.
Product
Reference Orange Book date
Documented entry date
Gap (days)
Binding clock
Sources
Eliquis (apixaban)
Nov. 21, 2026 (first listed patent)
Apr. 1, 2028 (earliest settled entry)
+497
Contract
[1][5][6]
Entresto (sacubitril/valsartan)
Nov. 8, 2026 (first listed patent)
July 22, 2025 (launch)
-474
Court and pediatric exclusivity
[1][8][10]
Januvia (sitagliptin)
Nov. 24, 2026 (salt patent)
May 26, 2026 (launch)
-182
Contract
[3][4][10]
Janumet (sitagliptin/metformin)
Jan. 21, 2029 (co-formulation patent)
May 2026 (settlement entry; day not stated)
about -971
Contract
[3][4]
Revlimid (lenalidomide)
Apr. 27, 2027 (first listed patent, derived)
Jan. 31, 2026 (unrestricted licenses)
-451
Contract, with volume limits before
[1][6][9]
Notes: The Revlimid reference date is derived from DrugPatentWatch’s statement that unrestricted entry came 451 days before the first listed expiry. [1] The Janumet gap uses May 26, 2026 as a stand-in for “May 2026,” which gives -971 days. Eliquis entry is subject to additional appeals and challenges. [5][6]
What the Table Shows
The five gaps sum to an absolute total of 2,575 days. The mean absolute gap is 515 days. The median absolute gap is 474 days. (Calculated.)
The Sign of the Error Changes
Entry came before the reference date four times and after it once. A fixed correction would help one product and hurt four. This is why one adjustment factor cannot rescue a one-date model.
The Size of the Error Is Large
The smallest gap is 182 days. The largest is 971 days. A forecast that misses LOE by six months misses at least two quarters of brand revenue decline.
Case Study: Eliquis and the 497-Day Contract Gap
The Eliquis date that matters is April 1, 2028. A patent date appears in the Orange Book. The April date appears in company filings and a press release.
What Did the Federal Circuit Fix?
On September 3, 2021, the BMS-Pfizer Alliance said the Federal Circuit affirmed the August 2020 district court decision. The decision covered the composition patent US 6,967,208 and the formulation patent US 9,326,945. The Alliance stated that the earliest date generic makers may launch is April 1, 2028, subject to additional appeals and challenges. [5]
What Bristol Myers Squibb Reports Now
The FY2025 10-K gives an estimated minimum US market exclusivity date of 2028. It says the settled generic companies “are permitted to launch in 2028, subject to additional challenges.” [6]
The European Contrast
The same filing says the EU apixaban composition patents and related supplementary protection certificates expire in November 2026. [6] The US and EU dates differ by jurisdiction and by clock. A global model needs a filer-level date for each country.
Case Study: Entresto, a Court Date Before a Patent Date
Entresto reached generic entry 474 days before its first listed patent date. The court calendar and a pediatric extension set the entry date, not the later patents.
How Did the ‘659 and ‘918 Patents Shape the Launch?
The Delaware court struck down the ‘659 combination patent in 2023, and Novartis appealed. [7] MSN received FDA approval on July 24, 2024. [7] Judge Richard Andrews denied Novartis’s request for a preliminary injunction based on the US 11,096,918 patent, which covers an amorphous form. [7][8] The Federal Circuit ruled on the ‘659 patent in January 2025. [8] MSN and Novartis settled the ‘659 dispute in June 2025. [8]
The Long Tail of Listed Patents
DrugPatentWatch reports a last listed Entresto patent date of May 9, 2036. [1] The launch came 3,944 days, about 10.8 years, before that date. (Calculated.) A model keyed to the last listed patent would place entry a decade late.
Case Study: Januvia and Janumet, Settlements Before Expiry
Why Did Generic Januvia Launch Before the Salt Patent Expired?
Settlements set the date. Merck’s FY2025 10-K says that, as a result of settlements on the sitagliptin salt-form patent, exclusivity extends through May 2026 for Januvia and Janumet and through July 2026 for Janumet XR. [4]
The Patent Was Valid. Entry Came Early Anyway.
Merck won in the Northern District of West Virginia in September 2022. [3] The Federal Circuit upheld the Patent Office’s finding that all challenged claims of US 7,326,708 are valid. Mylan, now Viatris, had brought the challenge. [14] Validity did not hold the launch to the patent date. The settlements moved it earlier.
A Market Clock Ran Before the Entry Date
Merck’s 10-K says the government set a price for Januvia that took effect on January 1, 2026, and set a price for Janumet and Janumet XR that takes effect on January 1, 2027. [4] The negotiated price started before generic entry. A model that starts price erosion on the LOE date misses the earlier step.
Case Study: Revlimid, One Drug With Several Entry Dates
How Do Volume-Limited Licenses Work?
A volume-limited license lets a named generic company sell a capped quantity before a later date. The BMS FY2022 10-K says Natco received a volume-limited license to sell generic lenalidomide in the United States starting in March 2022. [9] It also says other companies hold licenses to sell without volume limits starting January 31, 2026. [9] The FY2025 10-K says that as of January 31, 2026, the licenses are no longer volume-limited. [6]
The Gap Between the First and Last Dates
From March 2022 to January 31, 2026 is about 46 months. (Calculated.) The first generic entry date and the date of unrestricted competition are not the same date. A model with one LOE date gets one of them wrong.
Pomalyst: A Quarter, Not a Day
BMS says that for Pomalyst in the United States, generic entry is expected in the first quarter of 2026. [6] That is an expected event, stated as a quarter. A model should store the date type (confirmed or expected) along with the date.
Xarelto and Humira: Strength-Level and Approval-to-Launch Gaps
Xarelto: The Date Belongs to a Strength
Lupin announced on March 7, 2025 that it launched rivaroxaban tablets, 2.5 mg, as the equivalent of Janssen’s Xarelto 2.5 mg tablets. [11] The announcement covers one strength. A drug-level model that marks Xarelto as “generic” after that date overstates competition for the other strengths. The model needs a strength-level entry date.
Humira: Approval Is Not Entry
FDA approved the first Humira biosimilar, Amjevita, in September 2016. Amgen launched it in the United States on January 31, 2023. [1] That is about six years and four months. (Calculated.) A model that starts competition at approval is more than six years early.
The Formula: Brand LOE Equals the Earliest Filer Date, Set by the Latest Binding Clock
DrugPatentWatch states the binding-clock rule this way: the earliest launch date for a given company is the latest date among the clocks that apply to that company. [1] We add the second step. The brand’s LOE is the earliest of those dates across all filers.
In symbols, this is our original notation: LOE = min over filers f of ( max over clocks c of d(f, c) ). The inner maximum finds each company’s binding clock. The outer minimum finds the first company that can launch.
Worked Example: Januvia Filers Under This Formula
This example is an illustration built on documented facts. It is not a statement of any filer’s actual legal position.
Filer group
Clock that binds
d(f)
Source
Companies that settled with Merck
Contract
May 2026
[4]
Company with a failed validity challenge and no settlement (patent clock only)
Patent, with pediatric exclusivity
Nov. 24, 2026 to May 24, 2027
[3][14]
Brand LOE (minimum)
Earliest d(f)
May 2026
Calculated
The patent date is the maximum for the non-settling filer. The settlement date is the maximum for the settling filers. The brand LOE is the lowest of these values.
Why a Single Date Column Fails
A single date column forces you to pick one filer, one clock, and one strength. The table above has at least three different answers for one drug. The column cannot show which one binds, which one is confirmed, or which one has a volume cap.
Why the Number of Entrants Matters After the First Date
The first entry date starts the decline. The count of entrants sets its depth. FDA analyzed generic prices from 2015 through 2017 and reported the following.
“With six or more competitors, generic prices using both AMP and invoice prices show price reductions of more than 95%.” (Conrad & Lutter, FDA, 2019) [12]
What Happens to Price as Entrants Arrive?
The table gives median reductions in generic price relative to brand price, based on average manufacturer price (AMP) data. The six-competitor row shows the group with exactly six competitors; FDA’s text reports more than 95 percent for six or more.
Generic competitors
Median price reduction vs. brand (AMP)
1
38.6%
2
53.5%
3
67.8%
4
78.8%
5
85.6%
6 (exactly)
93.9%
Source: Conrad & Lutter (2019). [12] Reductions equal one minus the median generic-to-brand price ratio.
What This Means for the Model
Revlimid shows why. A first entrant with a volume cap does not produce the price of six competitors. A model needs the entrant count by quarter, which means it needs d(f) for every filer, not only the first.
Taxonomy: Six Clocks and Who Owns Each Date
DrugPatentWatch groups the forces behind a launch date into six clocks: patent, regulatory exclusivity, litigation, contract, approval and supply, and market. [1] We keep that grouping and add a column that shows who holds the date. The ownership column is our own classification.
Clock
Example in this article
Where the date lives
Public?
Patent
Januvia salt patent, Nov. 24, 2026 [3]
FDA Orange Book
Yes
Regulatory exclusivity
Pediatric exclusivity to July 15, 2025 (Entresto) [8]
FDA Orange Book exclusivity data and court orders
Yes
Litigation
Court order resetting MSN approval to no earlier than July 16, 2025 [8]
Court dockets
Yes, in part
Contract
Eliquis, Apr. 1, 2028 [5]
Company filings and press releases
Partly
Approval and supply
MSN approval, July 24, 2024 [7]
FDA, company statements
Partly
Market
Januvia negotiated price, Jan. 1, 2026 [4]
Company filings, government notices
Yes
Which Clocks Do Databases Capture Well?
Patent and exclusivity dates sit in structured public data. A model can read them in bulk. DrugPatentWatch describes pairing patent data with records on Paragraph IV challenges, litigation, tentative approvals, drug master files, suppliers, and price trends. [10]
Which Clocks Do Databases Miss?
The contract clock is the hardest. Companies disclose settlement dates in filings, often as a year or a month. [4][6] Volume caps and per-filer terms are less visible. An analyst must read the filing and enter the date by hand.
Scenario Analysis: Reading the Eliquis Calendar Three Ways
These scenarios use documented dates. They show how the model output changes with the input date. They do not forecast what will happen.
Scenario A: Orange Book Date Only
The model sets LOE at November 21, 2026. [1] This is the naive reading. It puts LOE about 16 months ahead of the documented earliest entry. (Calculated.)
Scenario B: Settlement Date
The model sets LOE at April 1, 2028, the earliest permitted launch for settled companies. [5][6] This matches the documented contract clock. It still carries the caveat that entry is subject to additional challenges. [5][6]
Scenario C: Settlement Date With a Disruption Flag
The model keeps April 1, 2028 as the base date. It adds a flag for appeals and new challenges. The flag lets an analyst test an earlier date without replacing the confirmed one. Company filings already use this caveat. [6]
What This Means for Forecasters, Brand Teams, Generic Filers, and Buyers
What This Means for Forecasting Teams
Replace the single LOE column with a table of dates by filer, strength, and clock. Store the status of each date (confirmed, expected, or estimated). The Pomalyst example shows why. [6]
What This Means for Brand Manufacturers
Brand teams hold the contract dates. Revlimid shows a graded entry in which the brand set volume limits for years before unrestricted competition. [9][6] A brand’s own forecast should model each license separately.
What This Means for Generic Filers
A filer’s real date is its own binding clock. The Januvia case shows that a company outside the settlement group faces a different date from the settled companies. [3][4]
What This Means for Wholesalers, Payers, and Buyers
Buyers who plan inventory or contracts around the Orange Book date can be early or late by a year or more. The gap table shows four early cases and one late case. A buyer needs the entry date, the strength, and the entrant count.
What Happens Next: Dates to Watch
Which Upcoming Dates Are Still Open?
November 8, 2026: Entresto’s first listed patent date. Generic entry already happened. [1][10]
November 21, 2026: Eliquis’s first listed patent date. Settled entry is not permitted before April 1, 2028. [1][5]
November 24, 2026: Januvia salt patent expiry. Generic entry already happened. [3][4]
May 24, 2027: end of pediatric exclusivity on the Januvia salt patent. [3]
April 1, 2028: earliest settled Eliquis entry. [5][6]
The first three dates are confirmed patent dates. The last is a confirmed contract date that carries a risk of change through appeals and challenges.
How to Fix the Model: A Schema Checklist
The fix is a data change, not a better forecast formula. Add these fields and fill them from primary documents.
Field 1: Filer
Store the company name. A drug without a filer field cannot hold more than one date.
Field 2: Product Strength
Store the strength. The Xarelto 2.5 mg launch shows why. [11]
Field 3: Binding Clock
Store which of the six clocks sets the date. [1]
Field 4: Date Status
Store “confirmed,” “expected,” or “estimated.” Treat quarter-level language such as Pomalyst’s as “expected.” [6]
Field 5: Volume or Condition Cap
Store any cap. The Revlimid licenses had one until January 31, 2026. [9][6]
Field 6: Source
Store a link to the filing, order, or database page. This lets a reviewer check the date.
How to Backtest Your Own LOE Model
A forecaster can run the same test on any set of products. The test takes one afternoon and shows where the model fails.
Step 1: Build a Set of Completed Entries
Pick products that already have generic or biosimilar entry. Record the first entry date and the date each later entrant shipped. Take the dates from filings, press releases, or FDA records. Keep the source for each date.
Step 2: Record What the Model Predicted at the Time
Use the prediction the model made before entry, not a prediction made with hindsight. If the model keyed on the first listed patent, use that date. If it keyed on the last listed patent, use that date.
Step 3: Compute Signed Gaps and Look at the Sign
Subtract the predicted date from the actual date. Report both the size and the sign. In our case set, four of five gaps were negative. A set with mixed signs tells you that missing data, not bias, drives the error.
Check A: Is the Gap Linked to a Binding Clock?
Label each case with the clock that set the date. If most large gaps share one clock, such as contract, add that clock to the model first.
Check B: Does the Gap Change by Strength or Filer?
Compare the entry date for each strength and each filer. Xarelto’s 2.5 mg launch and Revlimid’s staged licenses show where one date per drug hides differences. [11][9]
Check C: Does the Entrant Count Match the Price Path?
Compare the number of entrants by quarter with the observed price decline. The FDA table is a benchmark, and the 2015 to 2017 sample may not match a given drug. [12]
Five Common Errors in LOE Models
Error 1: Treating the Last Listed Patent as a Floor
Entresto launched 3,944 days before its last listed patent date. [1][10] A floor that is wrong by 10.8 years is not a floor. (Calculated.)
Error 2: Ignoring Pediatric Exclusivity
The Januvia salt patent date and the pediatric date differ by 181 days. [3] A model that drops the six months can place entry in the wrong half-year.
Error 3: Starting Competition at Approval
Humira’s first biosimilar had approval about six years and four months before launch. [1] Approval shows that FDA accepts the product. It does not show that the company can sell it.
Error 4: Using One Date for All Strengths and Filers
Lupin’s 2.5 mg rivaroxaban launch covered one strength. [11] A drug-level flag turns “one strength has generics” into “all strengths have generics.”
Error 5: Starting Price Erosion at LOE
Merck reports that the government price for Januvia took effect on January 1, 2026, before the May 2026 generic entry. [4] Price pressure can start before LOE and can build slowly after it.
Key Takeaways
The missing date is the filer-level entry date. A brand’s LOE is the earliest of those dates.
In five documented cases, entry was 182 to 971 days before the reference patent date four times and 497 days after it once. (Calculated.)
The mean absolute gap is 515 days, so a single-date model carries a large error with no consistent direction.
Eliquis’s earliest settled entry is April 1, 2028, subject to additional challenges. [5][6]
Entresto launched in July 2025, 474 days before its first listed patent date. [1][10]
Revlimid had a volume-limited license from March 2022 and unlimited licenses from January 31, 2026. [9][6]
FDA found that median generic prices fall 38.6 percent with one generic maker and 78.8 percent with four. [12]
Store dates by filer, strength, clock, status, cap, and source.
FAQ
Does a Patent Expiration Date Mean Generics Launch That Day?
No. Settlements, court orders, exclusivities, and supply readiness can move entry earlier or later. In our five cases, entry came before the reference date four times. [3][4][8][9]
What Is the Difference Between a Patent Expiry and Loss of Exclusivity?
Patent expiry is the end of one patent. Loss of exclusivity is the date the first generic reaches the market. LOE depends on all barriers.
Why Did Generic Januvia Launch Before Its Salt Patent Expired?
Settlements allowed it. Merck reports that exclusivity extends through May 2026 for Januvia and Janumet. [4] The salt patent expires on November 24, 2026. [3]
When Can Generic Eliquis Launch in the United States?
The BMS-Pfizer Alliance stated in 2021 that the earliest date is April 1, 2028, subject to additional appeals and challenges. [5] BMS’s FY2025 10-K repeats the 2028 timing for settled companies. [6]
How Does Pediatric Exclusivity Change the Entry Date?
It adds six months to existing protection. [15] Entresto’s ‘659 patent had expired, but pediatric exclusivity extended it to July 15, 2025. [8]
What Is a Volume-Limited Generic License?
It is a settlement license that lets a generic company sell a capped amount before a later unrestricted date. Revlimid had one for Natco from March 2022. [9]
Does Biosimilar Approval Mean Biosimilar Launch?
No. FDA approved the first Humira biosimilar in September 2016. The US launch came on January 31, 2023. [1]
How Many Generic Entrants Does It Take to Cut Prices Sharply?
FDA found median generic prices 78.8 percent below brand with four competitors and 93.9 percent below with six. [12] The text of the report states more than 95 percent for six or more.
Can One Strength of a Drug Have Generics While Others Do Not?
Yes. Lupin launched only the 2.5 mg strength of rivaroxaban on March 7, 2025. [11]
How Does DrugPatentWatch Treat the Entry Date?
DrugPatentWatch pairs patent data with records on Paragraph IV challenges, litigation, tentative approvals, suppliers, and price trends to estimate when a named company can ship. [10] Use its dates as a starting point and confirm them in primary documents.
References
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DrugPatentWatch. (2026, October 15). Patent expiration isn’t generic entry: How to find the date that counts. https://www.drugpatentwatch.com/blog/patent-expiration-isnt-generic-entry-how-to-find-the-date-that-counts/
Merck & Co., Inc. (2022, September 22). U.S. District Court rules in favor of Merck in sitagliptin phosphate patent lawsuit [Press release]. https://www.merck.com/news/u-s-district-court-rules-in-favor-of-merck-in-sitagliptin-phosphate-patent-lawsuit/
Merck & Co., Inc. (2026). Form 10-K for the fiscal year ended December 31, 2025. U.S. Securities and Exchange Commission. https://www.sec.gov/Archives/edgar/data/310158/000031015826000063/mrk-20251231.htm
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Bristol-Myers Squibb Company. (2026). Form 10-K for the fiscal year ended December 31, 2025. U.S. Securities and Exchange Commission. https://www.sec.gov/Archives/edgar/data/14272/000001427226000004/bmy-20251231.htm
IP Fray. (2025, June 17). Novartis and MSN settle part of chronic heart failure patent fight, but key patent remains. https://ipfray.com/novartis-and-msn-settle-part-of-chronic-heart-failure-patent-fight-but-key-patent-remains/
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