On February 21, 2025, Teva announced the US launch of Selarsdi, a biosimilar to Johnson & Johnson’s Stelara. On February 24, Samsung Bioepis and Biocon Biologics each announced a launch of their own ustekinumab product. [6] Three launches took place inside four days. Each company had to have finished product ready for the same short window.
That is the problem this article examines. A launch date is public. Courts, settlements, the Orange Book, the Purple Book and company filings put it on the calendar for everyone. A manufacturing slot is private. A sponsor reserves it for one product, one site and one date. When many sponsors read the same calendar, many reservations land on the same weeks. The reservation then depends on the capacity of one fill-finish line, one inspector’s decision, or one contract site.
We assembled public records on three recent launch clusters (Humira, Stelara and Prolia/Xgeva biosimilars) and one documented fill-finish failure (the former Catalent site in Bloomington, Indiana). We then applied that evidence to two 2028 loss-of-exclusivity events. This article separates documented facts from our analysis. Where we calculated a figure, we say so.
The Short Answer
Public records show that biosimilar launches cluster around a few shared dates. Seven Stelara biosimilars launched in the US in 2025, and six of them launched between January 1 and March 2025. [8] Two denosumab biosimilar settlements allowed entry on May 31 and June 1, 2025, one day apart. [10] Separately, a single fill-finish site in Indiana delayed or blocked FDA decisions for at least three outside customers. [1][2][4]
No source we reviewed says a biosimilar launch failed because of capacity. We found no public evidence of that, and we do not claim it. The evidence shows something narrower. Launch dates cluster, and fill-finish sites are a documented single point of failure. A launch plan that books capacity for one date and one site has no margin for either fact.
The Five Findings That Matter
Finding 1: Seven Stelara biosimilars launched in 2025, and six launched within the first quarter
Amgen’s Wezlana launched on January 1, 2025. [5] Selarsdi, Pyzchiva and Yesintek followed in February 2025. Otulfi and Steqeyma followed in March 2025, and Imuldosa launched on August 18, 2025. [8] Five of the seven were FDA-approved by October 2024, and none had launched at that date. [9]
Finding 2: Two denosumab settlements set entry dates one day apart
Sandoz and Amgen settled in April 2024. The settlement allowed Sandoz to launch from May 31, 2025. [10] Amgen settled with Celltrion in January 2025. That settlement allowed launch from June 1, 2025. [10]
Finding 3: Humira biosimilars waited 151 days, then arrived together
Amgen’s Amjevita launched on or about January 31, 2023. [11] Cyltezo launched on July 1, 2023, and Healio counted eight adalimumab biosimilars on the US market after the July launches. [12] The interval from January 31 to July 1 is 151 days (our calculation).
Finding 4: One fill-finish site in Indiana affected at least three outside sponsors
Regeneron, Scholar Rock and Incyte each received an FDA regulatory setback tied to the Bloomington site. [1][2][4] The FDA issued a warning letter to the site on November 20, 2025. [3]
Finding 5: Large biologics capacity is already full at one major CDMO
Samsung Biologics reported that its Plants 1 to 3 were fully utilized in 2025. Plant 4 reached full utilization in the third quarter of 2025. [16]
Methodology and Definitions
What data we analyzed
We reviewed published launch announcements, trade press, SEC filings and FDA-related reporting. The period runs from January 2023 to October 2026. We included a launch when a company or a reputable trade publication reported a US commercial launch or a contractual right to launch on a stated date. We included an FDA event when a company filing or a trade report tied it to a named site.
How we handled duplicates and dates
Several sources report the same launch. We used the earliest primary company date when a source gave one. Some sources give only a month. We list those as month-only and do not assign a day. All day counts in this article come from dates stated in the sources. We label each one as our calculation.
Limits of this analysis
We did not find public slot-reservation terms for any CDMO contract. We did not find any filing that names a biosimilar launch as delayed by a capacity shortage. So this article cannot measure how often reserved capacity failed. It can show how often launch dates collided, and how one documented site failure spread across customers.
Definitions used in this article
A shared launch calendar is the set of dates, public or contractual, on which several sponsors may launch the same class of product. Reserved capacity is manufacturing time, space or line availability that a sponsor books in advance for a product. Fill-finish is the final step of biologic manufacturing. It puts the drug substance into vials, prefilled syringes or autoinjectors. Official Action Indicated (OAI) is the FDA’s most severe post-inspection classification. It indicates an unacceptable state of compliance. [2]
How Does a Shared Launch Calendar Form?
A shared launch calendar forms when a few legal events fix dates for many companies. Three events do most of the work.
Settlement dates
A brand company can settle with several challengers and give each a licensed entry date. Amgen settled with Johnson & Johnson in 2023. The settlement moved Wezlana’s launch from late 2023 to no later than January 1, 2025. [5] Sandoz settled with Amgen in April 2024 and gained the right to launch denosumab biosimilars from May 31, 2025. [10] A settled date is known to the brand, to the challenger, and often to every competitor that tracks the docket.
Patent expiration
An expiring patent gives every competitor the same signal. Healio reported in October 2024 that Stelara stayed patent-protected until early 2025. [9] Merck states in its 2025 Form 10-K that the US compound patent for Keytruda expires in 2028. [13] Anyone who reads that filing sees that date.
Approval queues
FDA approval does not set a launch date, but it removes one barrier. By October 2024, five ustekinumab biosimilars held FDA approval. None had launched. [9] Approved products waited for a legal date. When the date arrived, all of them could move at once.
Stelara: Seven Biosimilars and One Calendar
Stelara (ustekinumab) generated $10.4 billion in sales in 2024, according to Johnson & Johnson’s financial statement as reported by the Center for Biosimilars. [6] Seven biosimilars launched in the US during 2025. [8]
The Stelara launch timeline
Product
Developer / commercializer
US launch
Reported list-price discount
Source
Wezlana (ustekinumab-auub)
Amgen, via Nuvaila (Optum Rx)
January 1, 2025
Not stated
[5]
Selarsdi (ustekinumab-aekn)
Alvotech / Teva
February 21, 2025
85%
[6][7]
Pyzchiva (ustekinumab-ttwe)
Samsung Bioepis / Sandoz
February 24, 2025
80%
[6][7]
Yesintek (ustekinumab-kfce)
Biocon Biologics
February 24, 2025
About 90% (WAC of roughly $3,000)
[6][7]
Otulfi (ustekinumab-aauz)
Formycon / Fresenius Kabi
March 2025
Not stated
[8]
Steqeyma (ustekinumab-stba)
Celltrion
March 2025
Not stated
[8]
Imuldosa (ustekinumab-srlf)
Accord BioPharma (Intas)
August 18, 2025
Not stated
[8]
The dates for Selarsdi, Pyzchiva and Yesintek are the dates of company press releases. [6] The sources give only the month for Otulfi and Steqeyma.
What the interval data shows
Three intervals matter here, and we calculated each from the dates above.
From the first launch (January 1) to the first February launch (February 21): 51 days.
From February 21 to February 24: 3 days, with three companies in that window.
From January 1 to the last of the six first-quarter launches: no more than 90 days, because the sources give only the month of March for the last two.
Why approved biosimilars did not launch earlier
The delay was legal, not technical. Healio reported in October 2024 that the fifth ustekinumab biosimilar, Imuldosa, had won approval. It also reported that none had launched. [9] Intas then expected a launch in the first half of 2025. [9] Imuldosa launched in August 2025. [8]
What a clustered launch asks of a supply chain
Our analysis: each of the seven sponsors needed finished product in the channel on or near its launch date. Six of them needed it within one quarter. Any sponsor that shared a CDMO, a fill-finish line or a device assembler with another sponsor competed for the same slots in the same weeks. The sources do not say which sponsors shared sites, so we cannot name a collision. We can say that the calendar made one possible.
Distribution deals narrowed the field further
Wezlana is available only through Nuvaila, a subsidiary of Optum. [5] Optum Rx placed Wezlana on its commercial formularies from January 1, 2025. [7] An exclusive channel changes launch-day demand. One buyer can pull a large volume of product in the first week.
Humira: A 151-Day Head Start, Then a Wave
What happened between January and July 2023
AJMC reported on January 31, 2023, that Amgen’s Amjevita had launched. [11] AbbVie’s settlements kept other adalimumab biosimilars off the market until 2023. Amgen’s deal gave Amjevita six months on the market before other biosimilars could launch. [11] Cyltezo, from Boehringer Ingelheim, entered on July 1, 2023, as the first interchangeable Humira biosimilar. [12]
Healio listed five more products expected to launch in July 2023: Yusimry (Coherus), Hulio (Mylan), Idacio (Fresenius Kabi), Yuflyma (Celltrion USA) and Abrilada (Pfizer). [12] It counted eight adalimumab biosimilars on the market after the July launches. [12]
What the Humira case teaches about reserved capacity
The Humira calendar had a known date, July 1, 2023, and a known first mover. Every sponsor that planned to launch in July had access to the same facts. Our analysis: the first mover could plan for a long solo period. The later sponsors had to plan for the same day. A planner who assumes a launch alone on day one has not read the settlement terms of the competitors.
Price signals from the first mover
Amjevita offered two list-price options. One was a 5% discount off Humira’s list price, for payers that keep PBM rebates. The other was a 55% discount, for payers that do not. [11] Sponsors that launched later had to choose their own price strategy in a market that already had a reference price.
Prolia and Xgeva: Two Settlement Dates One Day Apart
The denosumab entry dates
FDA approved Sandoz’s Jubbonti and Wyost in March 2024 as the first interchangeable denosumab biosimilars. [10] Sandoz and Amgen settled in April 2024. The settlement allowed launch from May 31, 2025. Sandoz announced the US launch on June 2, 2025. [10]
Celltrion settled with Amgen in January 2025. That settlement allowed Stoboclo and Osenvelt to launch from June 1, 2025. [10] Fresenius Kabi’s Conexxence and Bomyntra also had an Amgen settlement, from March 2025, that allowed launch in mid-2025. The exact date is not stated in the source. [10]
Which denosumab disputes stayed open
Amgen’s BPCIA litigation against Samsung Bioepis (Ospomyv and Xbryk, approved February 2025) was still pending when Pearce IP reported. [10] Amgen’s case against Accord/Intas was also pending. [10] Open litigation gives a sponsor an unknown date. A sponsor with an unknown date still plans manufacturing, and it plans against the dates of its settled competitors.
Why a one-day gap matters
Our analysis: two sponsors with entry rights on May 31 and June 1 cannot treat each other as sequential. Both need product in the channel in the same week. Both need device presentations and labeled stock ready before the first day. The calendar leaves no time for one sponsor to learn from the other.
What Happens When the Fill-Finish Site Fails? The Bloomington Case
The Bloomington, Indiana plant is the clearest public example of a fill-finish site that held many sponsors’ regulatory timelines. The plant is a filling site of about 950,000 square feet. It is the main fill-finish supplier for Novo Nordisk’s Wegovy. [1] This section covers originator and pipeline products. No source we reviewed ties a biosimilar launch to this site. We include the case because it shows how fast a single-site failure spreads.
Who owns the site
Novo Nordisk owns the plant. It is one of three former Catalent facilities that Novo Nordisk bought for $11 billion in 2024. [2] The deal closed in December 2024 as part of Novo Holdings’ $16.5 billion acquisition of the contract manufacturer Catalent. [1][3] Catalent stated that it “has no ownership, operational involvement, or oversight of the site.” [4]
The Bloomington timeline
Date
Event
Source
November 2024
FDA found quality control lapses at the facility
[1]
December 2024
Novo closed its purchase of the site
[3]
June 23 to July 14 (year implied as 2025)
FDA inspection
[3]
August 2025
Form 483 issued; FDA pushed back target dates for two Eylea HD supplements
[3][4]
September 2025
FDA issued a complete response letter to Scholar Rock for apitegromab
[2][4]
October 2025
FDA classified the site Official Action Indicated
[2][3]
November 19, 2025
FDA approved Eylea HD for macular edema after retinal vein occlusion and for monthly dosing; the prefilled syringe stayed unresolved
[2]
November 20, 2025
FDA warning letter issued (posted December 11, 2025)
[3]
March 10, 2026
Incyte reported a complete response letter for a Zynyz sBLA that named Catalent Indiana as the sole approvability issue
[4]
The interval from the end of the inspection on July 14 to the warning letter on November 20 is 129 days (our calculation, using the dates in the source).
What the FDA wrote
Fierce Pharma quoted the warning letter. The FDA wrote that it was “concerned that Novo Nordisk released batches in which your customers found mammalian hair contamination.” [3] The letter also said that “release of potentially contaminated drug products continued to occur well after the Novo Nordisk acquisition.” [3] The FDA cited failure to investigate more than 20 deviations tied to possible contamination in or near vial stopper regions. [3] It also cited failure to follow written procedures to prevent microbiological contamination of sterile products. [3]
The customers named in public records
Three outside sponsors appear in the sources with a setback tied to this site. Regeneron received a complete response letter for odronextamab and expected delays for Eylea HD. [1] Scholar Rock received a complete response letter in September 2025. [2] Incyte received a complete response letter in 2026. [4] The sources do not name every customer. Regeneron’s chief executive, Leonard Schleifer, said on an August 1, 2025 call that the site works “with the vast majority of the top bio-pharmaceutical companies in the world.” [1] He also said, “I believe that we may not be the only PDUFA that’s in snare.” [1]
How sponsors responded
Scholar Rock secured a second commercial fill-finish provider that starts in early 2026. Its chief executive, David Hallal, said the company “accelerated our timelines for an additional vialer.” [2] Regeneron planned to refile a prefilled Eylea HD syringe in January 2026, tied to validating a new third-party filler. [2] Regeneron is also building an in-house fill-finish plant in Rensselaer, New York, as part of a $7 billion investment announced in April 2025. [2]
The lesson on approval timing
Regeneron’s chief financial officer, Christopher Fenimore, said in November 2025 that the company would expect a complete response letter without a compliant filler. [2] The statement matters for launch planning. The FDA reviews the filler named in the application. A sponsor cannot swap sites at the last week without a regulatory filing and a new inspection history.
What the Bloomington case does not show
The case does not show that biosimilar launches failed. It does not show that a CDMO sold the same slot twice. It shows that one filing site can sit behind many applications. When it fails, each customer finds out in the same news cycle, and each starts the search for a replacement at the same time.
Where Does Biologics Capacity Sit Today?
Drug substance capacity at a large CDMO
Samsung Biologics reported 2025 revenue of more than 4.55 trillion South Korean won, up 30.3% from 2024. [16] Plants 1 to 3 were fully utilized. Plant 4 reached full utilization in the third quarter of 2025. [16] Plant 5 adds 180,000 liters and starts contributing revenue in 2026. Total antibody capacity then rises to 784,000 liters. [16]
Samsung’s chief executive, John Rim, said the Plant 4 ramp-up “supported reliable delivery for client programs.” [16] The source does not report a backlog figure. [16]
Fill-finish and device capacity
BioSpace reported in August 2026 that demand for sterile injectables is rising from biologics, biosimilars, GLP-1 drugs and some advanced therapies. [17] It cited a GMI Insights projection that the global prefilled syringe market will grow from $9.4 billion in 2026 to $20.3 billion by 2035. [17] About half of marketed autoinjector products were approved since 2017. [17]
The BioSpace article does not describe specific shortages or quantify available capacity. [17] We note that limit because a reader could mistake an expansion story for a shortage story. The documented facts are demand growth and company expansions. Examples include PCI Pharma Services’ $1 billion global expansion program, which includes sterile fill-finish and drug-device combination capability at US sites. [17]
Why presentation type matters for launch day
Our analysis: a vial and a prefilled syringe are different manufacturing jobs, even for the same antibody. A sponsor that books drug substance capacity for a launch has not booked the syringe line. A launch calendar that fixes the day for everyone fixes the syringe demand for everyone.
A Framework: Four Types of Capacity Collision
The following classification is original to this article. It is not an established industry taxonomy. We built it from the cases above.
Type
Definition
Documented example
Source
1. Same-window entry
Several sponsors hold entry rights within days of each other
Denosumab: May 31 and June 1, 2025; Stelara: three launches February 21 to 24, 2025
[6][10]
2. Released-queue entry
Approved products wait for one legal date, then all move
Five approved ustekinumab biosimilars, none launched, October 2024
[9]
3. Single-site dependency
One manufacturing site sits behind many applications or launches
Bloomington, Indiana: Regeneron, Scholar Rock, Incyte
[1][2][4]
4. Presentation bottleneck
Drug substance is ready, but the vial, syringe or autoinjector step limits supply
Eylea HD prefilled syringe unresolved after the monthly-dose approval
[2]
How to use the framework
A planner can score each launch against the four types. A Type 1 or Type 2 score means the calendar is shared. A Type 3 score means a site failure would reach several programs. A Type 4 score means the capacity booked for one stage may not cover the next.
Scenario Analysis: The 2028 Calendar
Keytruda: one product, a staggered date
Merck reported worldwide sales of $31,680 million for Keytruda and Keytruda Qlex in 2025. [13] The 10-K gives these dates:
US compound patent expiration: 2028.
Two additional US patents from the initial discovery: 2029, which Merck expects to be litigated.
Major EU markets: 2031.
Japan: 2032 to 2033.
China: 2028. [13]
Keytruda/Keytruda Qlex 2025 worldwide sales: $31,680 million. Merck expects Keytruda to be selected for Medicare price setting in 2027, effective January 1, 2029, and states that “U.S. sales of Keytruda will decline materially after that time.” [13]
Keytruda Qlex, the subcutaneous form, received FDA approval in September 2025. Its US patent expires in 2043. [13] A biosimilar to the intravenous form therefore faces a brand that has a second presentation.
Who is developing a biosimilar
Samsung Bioepis announced the start of a Phase III trial of SB27 in April 2024. The trial compares SB27 with Keytruda in metastatic non-squamous non-small cell lung cancer and planned to enroll about 616 patients. [14] The source names no other developers. We do not name others without a source.
Eliquis: a settlement date, not a patent date
Fierce Pharma reported in September 2021 that the Federal Circuit upheld a Delaware ruling on Eliquis’s composition-of-matter patent and a formulation patent. The companies expected US exclusivity until April 1, 2028. They had earlier expected generics between 2026 and 2031. [15] Eliquis generated $9.17 billion in 2020. [15] Check current litigation status in the sponsors’ latest filings before you rely on this date. The 2021 report is the source we verified.
Three scenarios for a 2028 launch planner
These scenarios are our analysis. They use documented patterns, not forecasts.
Scenario A: One sponsor, one date
The calendar gives a single entry date, and one sponsor holds the right. This matches the Humira first-mover period, when Amgen had 151 days alone. [11] Reserved capacity matches demand. The risk is the brand’s response, not a competitor’s launch.
Scenario B: Several sponsors, one date
Several sponsors hold a settled right to the same date. This matches Stelara in 2025 and Humira in July 2023. [8][12] Reserved capacity must cover the first-week peak for each sponsor, and the sponsors compete for fill-finish and device slots.
Scenario C: A contested date
The date depends on litigation. Merck expects the two 2029 Keytruda patents to be litigated. [13] A sponsor then books capacity against a date it does not control. The calendar can shift while the reservation holds.
How Could FDA’s 2025 Draft Guidance Change the Calendar?
The FDA issued an updated draft guidance on October 29, 2025. It would narrow the expectation that biosimilar applicants submit comparative clinical efficacy studies. [18] FDA called those studies “resource-intensive” and, for the most part, “unnecessary.” [18] The FDA would require only a pharmacokinetic similarity study and an immunogenicity assessment for products that meet the stated conditions. [18]
The three conditions in the draft
The draft applies where the reference product and the proposed biosimilar come from clonal cell lines, are highly purified and are well characterized analytically. It also requires that the link between quality attributes and clinical efficacy is generally understood, and that a human pharmacokinetic similarity study is feasible and clinically relevant. [18][19]
Interchangeability
The FDA intends to designate all approved biosimilars as interchangeable, according to Arnold & Porter. [18] Pearce IP reported a separate plan to drop the requirement for switching studies. [19] FDA Commissioner Marty Makary said that “by streamlining the biosimilar development process and helping advance interchangeability, we can achieve massive cost reductions for advanced treatments for cancer.” [18]
What this means for the launch calendar
Our inference, not a documented result: lower development cost and shorter timelines should add developers per reference product. Arnold & Porter’s authors expect lower costs and possibly faster entry. [18] The source does not quantify any reduction in timelines. [18][19] More developers per product means more sponsors reading the same patent calendar. The Stelara cluster of seven is the current high mark in our dataset.
Pricing Pressure: What Competitor Count Does to Price
FDA analyzed generic drugs that entered the market between 2015 and 2017. The analysis covered 181 products and 711 generic products with unique national drug codes. [20] Price falls as competitors enter:
Generic competitors
Price reduction (AMP-based)
Price reduction (invoice-based)
1
39%
31%
2
54%
44%
4
79%
73%
6 or more
More than 95%
More than 95%
Source: [20]. The study covers small-molecule generics, not biosimilars. We use it to show the price shape of competition. We do not apply the percentages to biosimilars.
Why this matters for a shared calendar
Our analysis: a sponsor that books capacity for a launch usually models a price. If the model assumes one or two competitors and seven arrive, the price curve moves far. The Stelara launch discounts reported in 2025 were 80%, 85% and about 90% off the reference list price, [7] but a list-price discount is not a net price. Net price depends on rebates and contracts, and the sources do not report net figures.
Can You See Your Competitors’ Dates? The Patent Data Gap
A launch planner needs two sets of dates: the competitors’ dates and the brand’s dates. For biologics, the public record is thin.
What the Purple Book shows
DrugPatentWatch reported that as of November 2023, the FDA’s Purple Book held 563 brand biologics, and only 11 disclosed any patent information. [21] That is 1.95% (our calculation from DrugPatentWatch’s figures). The Purple Book has no mandatory listing requirement, and the 2021 amendment triggers listing only after a sponsor enters the BPCIA patent dance. [21] DrugPatentWatch also states: “The dance reveals what was asserted. It does not reveal what exists.” [21] The article lists ten products although its text says eleven. [21] So treat the count as approximate.
Why this matters for capacity planning
A planner who cannot see a competitor’s settled date cannot see a competitor’s manufacturing date. Public sources, such as court records, SEC filings and press releases, fill part of the gap. DrugPatentWatch says it aggregates USPTO data, FDA biologics databases, ANDA filings, court litigation records and patent registers across 134 countries. [21] That description is the vendor’s own claim. We did not verify the coverage or the accuracy. Use any aggregated source as a pointer to the primary record, and confirm each date against the court order, filing or settlement announcement.
What This Means for Brand Manufacturers
Plan for a multi-sponsor day one
A brand that faces a settled entry date should expect several challengers on or near it. The Humira, Stelara and denosumab records show that pattern. [8][10][12] The brand’s own supply plan should assume the market changes in the first week.
Audit your own fill-finish dependencies
Regeneron’s case shows that a brand can lose approval timing because of a contractor’s site. [1][2] Brands should map which sites sit behind which products and applications. A second filler in the application before a loss-of-exclusivity date is easier to add than one added after a complete response letter.
Plan the next presentation
Merck holds a subcutaneous Keytruda product with a US patent to 2043. [13] A brand that moves patients to a new presentation changes the demand a biosimilar must meet. That is a commercial fact, not a manufacturing one, but it changes which presentation a challenger must supply.
What This Means for Biosimilar Developers
Do not read the calendar alone
Every developer in the Stelara cluster read the same Stelara patent record. The documented outcome was seven launches in 2025. [8] A developer should build a list of every rival with an approval or a settlement, and should assume that each one will launch on the first allowed day.
Ask for site-level facts
A developer should ask a CDMO which other launches use the same fill-finish line in the same weeks. Contract terms are private. The question is still fair to ask. The Bloomington case shows what a single-site failure costs. [2][3][4]
Keep a second site qualified
Scholar Rock took the step after its complete response letter. [2] The lead time was months. Sites need inspection and tech transfer. [2] The step is cheaper before a launch date than after.
What This Means for CDMOs
Utilization limits what you can promise
Samsung Biologics reported full utilization of Plants 1 to 3 and Plant 4 in 2025. [16] A CDMO in that position holds slots that are already committed. A customer’s request for an extra slot in a launch week competes with another customer’s launch.
Compliance failures spread to every customer
The Bloomington warning letter reached sponsors who did not own the site. [3][4] A CDMO’s inspection history is part of every customer’s regulatory file. A CDMO that tracks its customers’ launch calendars can see when several customers’ needs converge on one line.
Key Takeaways
Seven Stelara biosimilars launched in the US in 2025. Six launched between January 1 and March 2025. [8]
Three Stelara biosimilars launched between February 21 and February 24, 2025. [6]
Two denosumab biosimilar settlements allowed entry on May 31 and June 1, 2025. [10]
The Humira interval from Amjevita (about January 31, 2023) to Cyltezo (July 1, 2023) is 151 days (our calculation). [11][12]
FDA issued a warning letter to the Bloomington, Indiana fill-finish site on November 20, 2025. [3]
At least three outside sponsors (Regeneron, Scholar Rock and Incyte) had an FDA setback tied to that site. [1][2][4]
Samsung Biologics’ Plants 1 to 3 were fully utilized in 2025, and Plant 4 reached full utilization in the third quarter of 2025. [16]
Keytruda’s US compound patent expires in 2028. Two further patents expire in 2029, and Merck expects litigation on them. [13]
Public sources do not disclose CDMO slot-reservation terms, and none we reviewed attributes a biosimilar launch delay to a capacity shortage.
FAQ
How many Stelara biosimilars launched in the US in 2025?
Seven. They are Wezlana, Selarsdi, Pyzchiva, Yesintek, Otulfi, Steqeyma and Imuldosa. [8]
Why did approved ustekinumab biosimilars wait to launch?
Healio reported in October 2024 that Stelara was patent-protected until early 2025, and that none of the five approved biosimilars had launched. [9] Amgen’s settlement with Johnson & Johnson set Wezlana’s latest launch date at January 1, 2025. [5]
What does an Official Action Indicated classification mean?
It is the FDA’s most severe post-inspection classification. It indicates an unacceptable state of compliance. BioSpace reported that the Bloomington plant received this classification in October 2025. [2]
Did the Bloomington problems delay biosimilar launches?
No source we reviewed says so. The documented effects are on Regeneron, Scholar Rock and Incyte filings. [1][2][4]
When does Keytruda lose US patent protection?
Merck’s 2025 Form 10-K gives 2028 for the US compound patent. It lists two further US patents that expire in 2029 and that Merck expects to be litigated. [13]
When is generic Eliquis expected in the US?
A September 2021 Fierce Pharma report said the companies expected US exclusivity until April 1, 2028. [15] Confirm the current status in the sponsors’ newest filings.
How much does drug price fall as more generics enter?
FDA’s analysis of 2015 to 2017 entries found an AMP-based price reduction of 39% with one competitor, 54% with two, 79% with four, and more than 95% with six or more. [20]
Does the Purple Book list biologic patents?
Only in part. DrugPatentWatch reported that, as of November 2023, 11 of 563 brand biologics disclosed any patent information. [21]
What did FDA propose for biosimilars in October 2025?
FDA issued a draft guidance that would narrow the need for comparative efficacy studies. It also announced a plan to make interchangeability easier to reach. [18][19]
How large is Samsung Biologics’ antibody capacity?
The company reported that Plant 5 adds 180,000 liters in 2026 and brings total antibody capacity to 784,000 liters. [16]
References
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