{"id":1647,"date":"2017-10-24T10:45:46","date_gmt":"2017-10-24T15:45:46","guid":{"rendered":"https:\/\/www.drugpatentwatch.com\/blog\/?p=1647"},"modified":"2026-10-06T21:46:04","modified_gmt":"2026-10-07T01:46:04","slug":"as-blockbuster-drugs-fizzle-biotech-looks-warily-to-the-next-big-thing","status":"publish","type":"post","link":"https:\/\/www.drugpatentwatch.com\/blog\/as-blockbuster-drugs-fizzle-biotech-looks-warily-to-the-next-big-thing\/","title":{"rendered":"The Patent Cliff Math: What Actually Replaces a Lost Blockbuster"},"content":{"rendered":"\n
\"\"<\/figure>\n\n\n\n

In 2025, AbbVie’s Skyrizi and Rinvoq earned $25.866 billion. Humira, the drug they replace, earned $4.540 billion [1]. That is a ratio of 5.7 to 1 (our calculation).<\/p>\n\n\n\n

Most companies do not get that result. Johnson & Johnson’s Stelara lost $4.283 billion in sales in 2025, and Tremfya added $1.485 billion in the same disease area [2]. Tremfya therefore replaced 34.7% of the lost Stelara revenue (our calculation). Merck is in a harder position. Keytruda made 48.7% of Merck’s 2025 sales (our calculation from [3]), and Merck expects Keytruda to lose US patent protection in 2028 [4].<\/p>\n\n\n\n

This article measures the patent cliff with filings, not forecasts. It shows how fast blockbusters lose revenue, which dates matter through 2028, and which replacement routes worked in 2025 and early 2026. It also gives a four-route framework for sorting replacement strategies. DrugPatentWatch tracks the patent, exclusivity, and litigation records behind these dates, and the last section explains how to use them.<\/p>\n\n\n\n

The Short Answer: What Replaces a Lost Blockbuster?<\/strong><\/h2>\n\n\n\n

What Is the Pharmaceutical Patent Cliff?<\/strong><\/h3>\n\n\n\n

The patent cliff is the period when many branded drugs lose patent or regulatory exclusivity in a short span. Generic or biosimilar competitors then enter, and brand revenue falls. Evaluate counts more than $300 billion in prescription revenue that loses exclusivity between 2025 and 2030 [5].<\/p>\n\n\n\n

Four routes replace that revenue: reformulation of the same drug, a newer in-house drug, acquired assets, and new launches. In 2025, the first two routes carried most of the weight at AbbVie and Johnson & Johnson. The third route is now the largest in deal value [37].<\/p>\n\n\n\n

The Six Findings That Matter<\/strong><\/h3>\n\n\n\n
    \n
  1. Evaluate counts more than $300 billion of prescription revenue losing exclusivity from 2025 to 2030. Expiries total $52 billion in 2025 and peak at $104 billion in 2028 [5].<\/li>\n\n\n\n
  2. Keytruda and Keytruda Qlex made $31.680 billion of Merck’s $65.011 billion 2025 sales, or 48.7% (calculation from [3]).<\/li>\n\n\n\n
  3. Skyrizi and Rinvoq earned 5.7 times the 2025 revenue of Humira (calculation from [1]).<\/li>\n\n\n\n
  4. Tremfya replaced 34.7% of Stelara’s 2025 revenue loss. Tremfya and Darzalex together added 97.3% of that amount (calculation from [2]).<\/li>\n\n\n\n
  5. Keytruda Qlex was about 5.5% of Keytruda franchise sales in the second quarter of 2026 (calculation from [7]). Merck’s stated target is 30% to 40% [4].<\/li>\n\n\n\n
  6. Bristol Myers Squibb’s Legacy Portfolio was 45% of its 2025 sales, and the company guided that portfolio down 12% to 16% for 2026 [8][9].<\/li>\n<\/ol>\n\n\n\n

    Methodology and Definitions: How This Analysis Was Built<\/strong><\/h2>\n\n\n\n

    What Data Does This Analysis Use?<\/strong><\/h3>\n\n\n\n

    We used company filings and earnings releases for fiscal year 2025 and the second quarter of 2026. We used Evaluate and IQVIA for industry-wide estimates. We used FDA documents for exclusivity rules and generic price data.<\/p>\n\n\n\n

    We selected products where a loss of exclusivity has occurred, or where a company has named a date. We did not include products where the only source was a ranking or a forecast. Each calculated figure is labeled as a calculation. We did not remove duplicates across sources, because each product appears once, with figures from the company that reports it.<\/p>\n\n\n\n

    The analysis has four limits. First, a “replacement ratio” shows revenue change, not patient switching. Second, market growth can raise a replacement drug’s sales without any link to the lost drug. Third, company figures use net sales, and industry estimates use different bases. Fourth, we found no patient-level data for these products.<\/p>\n\n\n\n

    Patent Cliff vs. Loss of Exclusivity vs. Entry Date: Definitions<\/strong><\/h3>\n\n\n\n

    Three terms are often mixed up. They are different events.<\/p>\n\n\n\n

    What Is a Patent Expiration Date?<\/strong><\/h4>\n\n\n\n

    A patent expiration date is the last day a patent is in force. FDA says the term of a new patent is generally 20 years from its filing date [10]. FDA lists in the Orange Book each patent that claims the drug substance, the drug product, or a method of use [10].<\/p>\n\n\n\n

    What Is Regulatory Exclusivity?<\/strong><\/h4>\n\n\n\n

    Regulatory exclusivity is a marketing right that FDA grants on approval. It can run with a patent, but it does not have to. FDA lists these periods: orphan drug exclusivity of 7 years, new chemical entity exclusivity of 5 years, and 3 years for certain changes that need new clinical studies [10]. For biologics, the reference product has 12 years before FDA can approve a biosimilar, according to the Congressional Research Service [11].<\/p>\n\n\n\n

    What Is a Settlement-Determined Entry Date?<\/strong><\/h4>\n\n\n\n

    A settlement-determined entry date is the date a brand company and a generic company agree on in a patent case. It can be earlier or later than the patent expiration date. Section “Why Is an Orange Book Date Not a Launch Date?” below gives two examples.<\/p>\n\n\n\n

    Original Framework: Four Replacement Routes<\/strong><\/h3>\n\n\n\n

    Later in this article we sort replacement strategies into four routes. This is our own classification. It is not an established industry taxonomy. Readers who cite it should describe it as the DrugPatentWatch framework.<\/p>\n\n\n\n

    How Big Is the Patent Cliff From 2025 to 2030?<\/strong><\/h2>\n\n\n\n

    How Much Revenue Loses Exclusivity by 2030?<\/strong><\/h3>\n\n\n\n

    Two industry sources give two answers. Evaluate says more than $300 billion in prescription revenue loses exclusivity from 2025 to 2030 [5]. IQVIA says the global patent cliff to 2030 equals more than $230 billion of current list-price value [6].<\/p>\n\n\n\n

    \n

    Industry statistic: Evaluate reports that more than 400 drugs face patent expiry or loss of exclusivity by 2030, and that the ten largest expiries share $126 billion of at-risk revenue [12].<\/p>\n<\/blockquote>\n\n\n\n

    Evaluate’s data shows 68 products that will be blockbusters at the time of expiry. Exactly half of them will make more than $2 billion a year [12]. The ten largest expiries are about 42% of the $300 billion headline (our calculation). Because the headline is a floor, the true share is at most 42%.<\/p>\n\n\n\n

    Why Do Patent Cliff Estimates Differ?<\/strong><\/h3>\n\n\n\n

    The two estimates differ in how they measure value. Evaluate counts revenue [5]. IQVIA counts current list-price value [6]. List prices are higher than net revenue in most cases, so you would expect a list-price figure to be higher. Here it is lower, so scope and product selection must also differ. The sources do not publish a full reconciliation.<\/p>\n\n\n\n

    IQVIA adds that up to 65% of the current revenue of some big pharma companies is at risk, and that a further $200 billion to $250 billion is at risk by 2035 [6]. Do not add the Evaluate and IQVIA numbers together. They count the same market in different ways.<\/p>\n\n\n\n

    When Does the Patent Cliff Peak?<\/strong><\/h3>\n\n\n\n

    Evaluate shows expiries of $52 billion in 2025, rising to a peak of $104 billion in 2028, the year Keytruda is expected to lose exclusivity [5]. The peak year is therefore 2.0 times the first year (our calculation). Evaluate also says each year from 2025 puts more than 3% of total industry revenue at risk [5].<\/p>\n\n\n\n

    How Does This Cliff Compare With the Early 2010s?<\/strong><\/h4>\n\n\n\n

    Evaluate says the last cliff of this kind came in the early 2010s. Statins such as Lipitor, antidepressants such as Lexapro and Cymbalta, antipsychotics such as Seroquel, Abilify, and Zyprexa, and the pain drug Lyrica lost protection in that period. Sales growth was slow for several years, and companies moved R&D budgets away from these areas [5].<\/p>\n\n\n\n

    Pfizer showed the effect early. For 2012, Pfizer guided revenue to $62.2 billion to $64.7 billion. That was a decline of nearly 5% at the low end [13].<\/p>\n\n\n\n

    How Fast Does a Blockbuster Lose Revenue After Generic or Biosimilar Entry?<\/strong><\/h2>\n\n\n\n

    Short answer: fast, in two steps. Price falls first, as more competitors enter. Volume falls next, as payers and doctors move patients. Four cases show the pattern.<\/p>\n\n\n\n

    Lipitor in 2011: What Happened After Generic Entry?<\/strong><\/h3>\n\n\n\n

    Lipitor reached peak annual sales of $12.9 billion in 2006. By 2010 it made $10.7 billion [13]. That is a 17% fall in four years before any generic arrived (our calculation).<\/p>\n\n\n\n

    Pfizer settled with Ranbaxy in June 2008. The settlement allowed Ranbaxy to launch a generic on November 30, 2011. That was about 20 months after the main patent was due to expire [14]. Ranbaxy also held 180 days of exclusivity from that date [17].<\/p>\n\n\n\n

    Two generics launched on the first day. One was Ranbaxy’s. The other was an authorized generic made by Pfizer and sold by Watson. Both cost about one third less than Lipitor [15]. Lipitor sales fell by half within about a week [15]. The US portion of Lipitor was still making about $7.9 billion a year before that fall [15].<\/p>\n\n\n\n

    Humira After 2023: How Large Was the Decline in Year Three?<\/strong><\/h3>\n\n\n\n

    The first US Humira biosimilar launched in late January 2023. By the end of the first quarter, global Humira sales had fallen 25% [18]. In 2025, Humira revenue fell another 49% [19]. Full-year Humira revenue was $4.540 billion, and fourth-quarter revenue was $1.246 billion, down 25.9% [1].<\/p>\n\n\n\n

    AbbVie guides Humira to $2.9 billion in 2026 [20]. That guidance assumes further decline, but it is a company forecast, not a reported result.<\/p>\n\n\n\n

    Stelara in 2025: Did Patients Move to Biosimilars?<\/strong><\/h3>\n\n\n\n

    Stelara sales fell 41.3% in 2025, from $10.361 billion to $6.078 billion [2]. US Stelara sales were about $3.8 billion in 2025 [2]. In the first quarter of 2026, Stelara sales were $656 million, about 60% below the prior year [21].<\/p>\n\n\n\n

    The J&J chief financial officer, Joseph Wolk, said many patients chose other treatments, such as Tremfya, and did not switch to the biosimilars [21]. This is important for generic and biosimilar planning. The brand owner can capture part of the switch with its own newer drug.<\/p>\n\n\n\n

    Entresto in 2025: What Does a Contested Launch Look Like?<\/strong><\/h3>\n\n\n\n

    Novartis lost a bid in August 2025 to stop MSN Pharmaceuticals from launching a generic Entresto in the US [24]. Five patents cover Entresto. The first expired on July 15, 2025, and the last runs through 2036 [23]. Novartis is still in litigation with a generic manufacturer to protect its Entresto rights [22].<\/p>\n\n\n\n

    Fourth-quarter 2025 Entresto sales were $1.253 billion, down 43% [22]. Entresto kept growing outside the US [22].<\/p>\n\n\n\n

    Why Does Price Fall Faster Than Volume?<\/strong><\/h4>\n\n\n\n

    FDA data shows how generic prices fall as the number of makers rises. Using average manufacturer price data, one generic maker prices 39% below the brand price before generic entry. Two makers price 54% below. Four makers price 79% below. Six or more makers price more than 95% below [26]. FDA’s own report also gives invoice-based figures, which are lower in each case. For two makers, the invoice-based figure is 44% [25].<\/p>\n\n\n\n

    The FDA data covers generic competition, not biosimilars. Use it as a guide to small-molecule price behavior only.<\/p>\n\n\n\n

    Table 1 collects the four cases and Revlimid.<\/p>\n\n\n\n

    Table 1. Revenue change after loss of exclusivity (reported figures)<\/p>\n\n\n\n

    Product<\/th>Company<\/th>Entry event<\/th>Reported change<\/th>Source<\/th><\/tr><\/thead>
    Lipitor<\/td>Pfizer<\/td>Generic entry, Nov. 30, 2011<\/td>Sales fell by half in about one week<\/td>[15]<\/td><\/tr>
    Humira<\/td>AbbVie<\/td>First US biosimilar, late Jan. 2023<\/td>Global sales down 25% by end of Q1 2023; down 49% in 2025 to $4.540 billion<\/td>[18][19][1]<\/td><\/tr>
    Stelara<\/td>Johnson & Johnson<\/td>Biosimilar competition, 2025<\/td>Down 41.3% in 2025 to $6.078 billion<\/td>[2]<\/td><\/tr>
    Entresto<\/td>Novartis<\/td>US generic entry, Q3 2025<\/td>Q4 2025 sales down 43% to $1.253 billion<\/td>[22]<\/td><\/tr>
    Revlimid<\/td>Bristol Myers Squibb<\/td>Volume-limited entry, then limits expired Jan. 2026<\/td>Q4 2025 sales $602 million, down 55%<\/td>[30][9]<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

    Patent Cliff Timeline: The Dates That Matter Through 2028<\/strong><\/h2>\n\n\n\n

    The table below separates confirmed events from company expectations. A confirmed event has happened and appears in a filing or a press report. An expected event is a date a company names, and it can change.<\/p>\n\n\n\n

    Table 2. Selected loss-of-exclusivity events<\/p>\n\n\n\n

    Product<\/th>Event<\/th>Date<\/th>Status<\/th>Source<\/th><\/tr><\/thead>
    Humira<\/td>First US biosimilar launch<\/td>Late January 2023<\/td>Confirmed<\/td>[18]<\/td><\/tr>
    Stelara<\/td>Biosimilar competition begins to reduce sales<\/td>2025<\/td>Confirmed<\/td>[2]<\/td><\/tr>
    Entresto<\/td>US generic entry<\/td>Q3 2025<\/td>Confirmed<\/td>[22]<\/td><\/tr>
    Revlimid<\/td>Volume limits on generic entry expire<\/td>January 2026<\/td>Confirmed (company-reported)<\/td>[9]<\/td><\/tr>
    Januvia, Janumet<\/td>US exclusivity ends<\/td>May 2026<\/td>Reported<\/td>[28]<\/td><\/tr>
    Bridion<\/td>US exclusivity ends<\/td>July 2026<\/td>Reported<\/td>[28][29]<\/td><\/tr>
    Eliquis<\/td>Earliest permitted US generic launch<\/td>April 1, 2028<\/td>Expected, subject to further challenges<\/td>[27]<\/td><\/tr>
    Keytruda<\/td>US patent protection ends<\/td>2028<\/td>Expected<\/td>[4]<\/td><\/tr>
    Entresto<\/td>Last listed patent expires<\/td>2036<\/td>Reported<\/td>[23]<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

    Keytruda Patent Expiration in 2028: What Happens Next?<\/strong><\/h3>\n\n\n\n

    Keytruda is expected to lose patent protection in 2028 [4]. The company expects growth to continue until then [28]. Merck’s chief executive, Robert Davis, told analysts in August 2026 that the transition would bring a shallow decline and a fast return to growth [29]. That is a management view, not a result.<\/p>\n\n\n\n

    Keytruda was not on CMS’s list of drugs selected for Medicare price negotiation for 2028. CMS’s expansion of the orphan drug exclusion delays Keytruda and Opdivo to later price years [40].<\/p>\n\n\n\n

    Eliquis Generic Launch: Is April 1, 2028 Firm?<\/strong><\/h3>\n\n\n\n

    The Bristol Myers Squibb and Pfizer alliance stated in September 2021 that the Federal Circuit affirmed validity and infringement of the composition of matter patent (US 6,967,208) and the formulation patent (US 9,326,945). The alliance said the earliest generic launch is April 1, 2028, “subject to additional appeals and challenges” [27].<\/p>\n\n\n\n

    Eliquis kept growing in the meantime. Bristol guided worldwide Eliquis growth of 10% to 15% for 2026 [9]. A Medicare price cut under the Inflation Reduction Act took effect in 2026, and the Bristol chief executive said it helps Eliquis reach more patients [32].<\/p>\n\n\n\n

    Why Is an Orange Book Date Not a Launch Date?<\/strong><\/h4>\n\n\n\n

    The Lipitor and Eliquis cases show the gap. The Lipitor entry date came from a settlement and fell about 20 months after the main patent date [14]. The Eliquis entry date came from a court ruling and settlements, not from a patent expiration date alone [27]. A calendar of raw expiration dates will give wrong answers for both drugs.<\/p>\n\n\n\n

    Who Is Exposed? Company Concentration of the Patent Cliff<\/strong><\/h2>\n\n\n\n

    Merck: How Much of the Company Is Keytruda?<\/strong><\/h3>\n\n\n\n

    Merck’s 2025 sales were $65.011 billion. Keytruda and Keytruda Qlex made $31.680 billion, up 7% [3]. That share is 48.7% (our calculation). Merck guided 2026 sales to $65.5 billion to $67.0 billion [3].<\/p>\n\n\n\n

    Other Merck products are also losing protection. Januvia and Janumet lost US exclusivity in May 2026, and Bridion lost US exclusivity in July 2026 [28]. Merck bought Verona Pharma in October 2025, and the Verona product Ohtuvayre made $204 million in the second quarter of 2026 [29].<\/p>\n\n\n\n

    Bristol Myers Squibb: Why Is the Legacy Portfolio 45% of Sales?<\/strong><\/h3>\n\n\n\n

    Bristol’s 2025 revenue was $48.2 billion, and its Growth Portfolio made $26.4 billion, up 17% [30]. The Legacy Portfolio fell 15% to about $21.8 billion [31]. Fierce Pharma reports the legacy figure as $21.7 billion [32]. The Legacy Portfolio was 45% of total sales [8].<\/p>\n\n\n\n

    The Growth Portfolio exceeded the Legacy Portfolio by $4.6 billion (our calculation). Revlimid made $602 million in the fourth quarter of 2025, down 55% [30]. Bristol guided the Legacy Portfolio down 12% to 16% in 2026 [9].<\/p>\n\n\n\n

    Novartis: Which Products Carry the Generic Exposure?<\/strong><\/h3>\n\n\n\n

    Novartis sales rose 8% in 2025 to $54.5 billion, despite generic entry for Entresto [35]. Kisqali made $4.8 billion, up 58%. Pluvicto made $2.0 billion, up 43%. Leqvio made $1.2 billion, up 59% [33]. Novartis said further erosion of three blockbusters, including Entresto, would leave a $4 billion gap in 2026 sales [35]. The company expects low single-digit sales growth in 2026 and a low single-digit decline in core operating income [34].<\/p>\n\n\n\n

    What Is the Large Pharma Growth Gap?<\/strong><\/h4>\n\n\n\n

    Evaluate estimates that the large pharma growth gap is $94 billion of 2030 revenue [12]. The gap is the difference between the revenue that current portfolios will deliver and the revenue that large companies need to hit growth targets. Evaluate says its calculation method was inspired by an EY analysis [12].<\/p>\n\n\n\n

    What Replaces a Lost Blockbuster? Four Replacement Routes<\/strong><\/h2>\n\n\n\n

    The four routes below are the DrugPatentWatch framework. Each route has a different timing, cost, and risk.<\/p>\n\n\n\n

    Route A: Reformulate the Same Drug<\/strong><\/h3>\n\n\n\n

    The company moves patients from the old form of the drug to a new form with new protection. Keytruda Qlex is the main example. It is the subcutaneous form of Keytruda. FDA approved it in 2025 for the solid tumor indications of the intravenous product [4]. Subcutaneous forms of Tecentriq and Opdivo were approved earlier [4].<\/p>\n\n\n\n

    Sales are growing quickly from a low base. Keytruda Qlex made $40 million in 2025 [3]. It made $128 million in the first quarter of 2026 and $463 million in the second [29][7]. The first half of 2026 therefore totals $591 million (our calculation). A permanent billing code took effect in April 2026, and Zacks links that code to higher adoption [29].<\/p>\n\n\n\n

    The route carries a legal risk. Merck launched Qlex while patent litigation with Halozyme over the hyaluronidase enzyme was still open [4].<\/p>\n\n\n\n

    Route B: Move Patients to a Newer In-House Drug<\/strong><\/h3>\n\n\n\n

    The company moves patients to a different drug it already owns in the same disease area. AbbVie used this route for Humira. Skyrizi and Rinvoq made a combined $25.9 billion in 2025. AbbVie said that figure was more than $4.5 billion above peak Humira sales [41]. Johnson & Johnson used the route for Stelara. Tremfya sales rose 40.5% in 2025 to $5.155 billion [2].<\/p>\n\n\n\n

    This route works only if the newer drug is ready before the old drug loses protection. It also depends on payer coverage. AbbVie expects a low single-digit price headwind on both Skyrizi and Rinvoq in 2026 and in the next few years [20].<\/p>\n\n\n\n

    Route C: Buy or License the Replacement<\/strong><\/h3>\n\n\n\n

    The company acquires revenue or late-stage assets. EY reported that total life sciences deal value rose 81% in 2025 to $240 billion [36]. IQVIA lists four deals above $10 billion in 2025: Johnson & Johnson with Intra-Cellular ($14.6 billion), Novartis with Avidity ($12.7 billion), Merck with Verona ($11.1 billion), and Pfizer with Metsera ($10 billion) [37]. Sources report the Verona price as both $10 billion [36] and $11.1 billion [37], because they measure value differently.<\/p>\n\n\n\n

    Licensing also grew. J.P. Morgan data, as reported by Vin Ventures, shows $82.7 billion of announced biopharma licensing value in the first quarter of 2026. The same source projects $140 billion to $160 billion of M&A for 2026 [38]. That figure is a projection.<\/p>\n\n\n\n

    The route has a lag. The Johnson & Johnson purchase of Intra-Cellular added Caplyta, which made $700 million in 2025 [39]. The Merck purchase of Verona added a product that made $204 million in the second quarter of 2026 [29].<\/p>\n\n\n\n

    How Did the Pfizer and Metsera Bidding Work?<\/strong><\/h4>\n\n\n\n

    Pfizer first agreed to pay $4.9 billion up front for Metsera. Novo Nordisk then made a $6.5 billion counter-offer. Pfizer raised its offer to $10 billion, which included contingent value rights, and won [37].<\/p>\n\n\n\n

    Route D: Launch New Products in New Indications<\/strong><\/h3>\n\n\n\n

    The company grows other products that are not in the same disease area. Novartis used this route with Kisqali, Pluvicto, and Leqvio [33]. Merck’s new products Winrevair ($1.443 billion) and Capvaxive ($759 million) made about $2.2 billion in 2025 (our calculation from [3]). Bristol’s Growth Portfolio is the same route at a larger scale [30].<\/p>\n\n\n\n

    Which Route Is Fastest?<\/strong><\/h4>\n\n\n\n

    Routes B and D show revenue in the same year, because the products are already on the market. Route A depends on conversion speed. Route C depends on closing dates and launch dates. These are observations from the cases above, not a ranking of value.<\/p>\n\n\n\n

    Replacement Scorecard: Did the Math Work in 2025?<\/strong><\/h2>\n\n\n\n

    Table 3 compares revenue lost with revenue gained. Figures marked “calc.” come from reported percentages and are approximate.<\/p>\n\n\n\n

    Table 3. Replacement scorecard for 2025 (our calculations from reported figures)<\/p>\n\n\n\n

    Company<\/th>Declining product<\/th>Replacement<\/th>Offset (calculation)<\/th>Source<\/th><\/tr><\/thead>
    AbbVie<\/td>Humira: down 49% to $4.540 billion (about -$4.4 billion, calc.)<\/td>Skyrizi plus Rinvoq: up more than $8 billion to $25.866 billion<\/td>At least 1.8 times<\/td>[1][19][41]<\/td><\/tr>
    Johnson & Johnson<\/td>Stelara: down $4.283 billion to $6.078 billion<\/td>Tremfya: up $1.485 billion. Darzalex: up $2.681 billion<\/td>Tremfya 34.7%. Tremfya plus Darzalex 97.3%<\/td>[2]<\/td><\/tr>
    Bristol Myers Squibb<\/td>Legacy Portfolio: down 15% to about $21.8 billion (about -$3.8 billion, calc.)<\/td>Growth Portfolio: up 17% to $26.4 billion (about +$3.8 billion, calc.)<\/td>About 1.0 times. Total revenue flat at $48.2 billion<\/td>[30][31]<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

    AbbVie: Why Is the Offset Above 1.0?<\/strong><\/h3>\n\n\n\n

    AbbVie’s replacement drugs grew faster than Humira shrank. Skyrizi rose 50% and Rinvoq rose 39% in 2025 [19]. AbbVie’s total net revenue grew 8.6% to $61.160 billion [1]. The company guides Skyrizi to $21.5 billion and Rinvoq to $10 billion in 2026 [20].<\/p>\n\n\n\n

    Johnson & Johnson: How Much of Stelara Did Tremfya Replace?<\/strong><\/h3>\n\n\n\n

    Tremfya replaced about one third of the Stelara loss in the same disease area. Darzalex, a cancer drug, added more revenue than Tremfya did. The Darzalex gain is a portfolio-level offset, not a patient-level replacement. The J&J filing says the Stelara decline cut worldwide Innovative Medicine operational sales growth by about 10.4 percentage points [2]. Immunology sales fell 11.8% to $15.7 billion [2].<\/p>\n\n\n\n

    Bristol Myers Squibb: Why Is the Net Result Flat?<\/strong><\/h3>\n\n\n\n

    The legacy loss and the growth gain were close to equal in dollars. Total revenue was $48.2 billion in 2025, against $48.3 billion in 2024 [31]. The Legacy Portfolio figure includes Eliquis, which kept growing [32]. The legacy decline therefore comes from Revlimid, Pomalyst, Sprycel, and Abraxane [8].<\/p>\n\n\n\n

    Does an Offset Ratio Prove Replacement?<\/strong><\/h4>\n\n\n\n

    No. A ratio compares two revenue changes. It does not show that the same patients moved. Market growth, price changes, and new indications also change revenue. Use the ratio as a screening metric only.<\/p>\n\n\n\n

    How Does AbbVie in 2025 Compare With Pfizer in 2012?<\/strong><\/h4>\n\n\n\n

    Pfizer guided revenue down in 2012, the first full year after Lipitor lost protection [13]. AbbVie reported revenue up 8.6% in 2025, the second full year after Humira biosimilars launched [1]. The two cases are 13 years apart, and the companies differ in size and portfolio. The comparison shows only that a replacement drug can be ready before the cliff.<\/p>\n\n\n\n

    How Does the Inflation Reduction Act Change the Patent Cliff?<\/strong><\/h2>\n\n\n\n

    Which Drugs Did CMS Select for 2028 Medicare Negotiation?<\/strong><\/h3>\n\n\n\n

    On January 27, 2026, CMS released the third list for the Medicare Drug Price Negotiation Program. It names 15 drugs for 2028: 10 from Part D and 5 from Part B [40]. Milliman notes that several large blockbusters are absent. It also says the expanded orphan drug exclusion makes Darzalex ineligible under its current approvals, and delays Opdivo and Keytruda to later years [40].<\/p>\n\n\n\n

    How Does Price Negotiation Interact With Generic Entry?<\/strong><\/h3>\n\n\n\n

    Negotiated prices apply while a brand still has exclusivity. Generic entry then cuts prices further. The two effects stack. Eliquis shows the order. The Medicare price took effect in 2026, and generics are not expected before April 2028 [32][27]. AbbVie also names IRA pricing as a headwind for Imbruvica in 2026 [41].<\/p>\n\n\n\n

    Does Negotiation Replace the Patent Cliff?<\/strong><\/h4>\n\n\n\n

    No. The two mechanisms act at different times and with different size. Negotiation lowers the price of a drug that still has protection. Generic competition removes the protection. FDA data shows prices fall more than 95% below the brand price with six or more generic makers [26].<\/p>\n\n\n\n

    What This Means for Brand Manufacturers, Generic Developers, and Analysts<\/strong><\/h2>\n\n\n\n

    What This Means for Brand Manufacturers<\/strong><\/h3>\n\n\n\n

    Conversion speed is the key number. Merck’s target is 30% to 40% of Keytruda use on the subcutaneous form within about 18 to 24 months of approval [4]. Qlex was about 5.5% of Keytruda sales in the second quarter of 2026 (our calculation from [7]). The target window runs to about September 2027, so this is not yet a miss. The gap is 24.5 percentage points to the low end of the target.<\/p>\n\n\n\n

    What This Means for Generic and Biosimilar Developers<\/strong><\/h3>\n\n\n\n

    Stelara shows that an entry date does not guarantee share. Many patients went to other brands [21]. Entresto shows that a launch can start while litigation continues [22][24]. Developers should plan for a branded switch strategy as well as a patent case.<\/p>\n\n\n\n

    What This Means for Analysts and Investors<\/strong><\/h3>\n\n\n\n

    Track four numbers for each product: the franchise share of company sales, the conversion rate of any new form, the confirmed entry date, and the exposure to price negotiation. Treat each company’s guidance as a forecast. Treat quarterly sales as a result. This article gives facts, not investment advice.<\/p>\n\n\n\n

    Scenario Analysis: Keytruda Conversion Before 2028<\/strong><\/h2>\n\n\n\n

    This scenario is arithmetic, not a forecast. It uses the 2025 Keytruda franchise of $31.680 billion as a fixed base [3]. It asks what each conversion rate means in Qlex-equivalent revenue. Qlex covers the solid tumor indications of intravenous Keytruda [4], so the real addressable base is smaller than the total.<\/p>\n\n\n\n

    What Does Each Conversion Rate Mean in Dollars?<\/strong><\/h3>\n\n\n\n

    Table 4. Keytruda conversion scenarios on the 2025 base (our calculations)<\/p>\n\n\n\n

    Share of franchise on Qlex<\/th>Qlex-equivalent revenue at $31.680 billion base<\/th>Reference point<\/th><\/tr><\/thead>
    5.5%<\/td>About $1.7 billion<\/td>Q2 2026 actual share [7]<\/td><\/tr>
    10%<\/td>$3.2 billion<\/td>Illustrative<\/td><\/tr>
    20%<\/td>$6.3 billion<\/td>Illustrative<\/td><\/tr>
    30%<\/td>$9.5 billion<\/td>Low end of Merck’s target [4]<\/td><\/tr>
    40%<\/td>$12.7 billion<\/td>High end of Merck’s target [4]<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

    What Could Change the Scenario?<\/strong><\/h3>\n\n\n\n

    Does the Halozyme Litigation Matter?<\/strong><\/h4>\n\n\n\n

    Halozyme’s patent litigation over the hyaluronidase enzyme was open when FDA approved Qlex [4]. A loss would affect the one route Merck has built for the 2028 date. We found no ruling that ends the dispute.<\/p>\n\n\n\n

    How Ready Are Biosimilars?<\/strong><\/h4>\n\n\n\n

    IQVIA says only 10% of the molecules that lose patent protection from 2025 to 2034 have biosimilars in development [42]. A date on a calendar does not guarantee a competitor. For each product, check approved and filed biosimilars before you model a decline.<\/p>\n\n\n\n

    How to Build a Patent Cliff Calendar With DrugPatentWatch<\/strong><\/h2>\n\n\n\n

    DrugPatentWatch compiles patent expiration, exclusivity, litigation, and generic-entry records for FDA-approved drugs. Use it to find the patents and exclusivities for a product. Then check each date against the docket and the company’s filings, as this article did. A database date is a starting point, as the Lipitor and Eliquis cases show.<\/p>\n\n\n\n

    How Do You Record Four Dates for Each Product?<\/strong><\/h3>\n\n\n\n

    Record four dates: the patent expiration date, the regulatory exclusivity date, the settlement or court-set entry date, and the observed entry date. Keep the observed date empty until a launch happens. Label each date as confirmed or expected.<\/p>\n\n\n\n

    Which Sources Should You Check First?<\/strong><\/h4>\n\n\n\n

    Check the Orange Book for small molecules and the Purple Book for biologics. Check SEC filings for company statements on entry dates, as with the Eliquis statement [27]. Check court dockets for settlement terms.<\/p>\n\n\n\n

    Key Takeaways<\/strong><\/h2>\n\n\n\n