Biologics and Biosimilars Landscape 2024: IP, Policy, and Market Developments 

Last year marked an all-time record of 18 Food and Drug Administration (FDA) biosimilar approvals, bringing the total number of FDA-approved biosimilars to 63. Forty-one of those biosimilars have launched in the U.S. market. These record-breaking numbers reflect a growing momentum in acceptance and integration of biosimilars into the U.S. market that has been driven by a projected market value of $10 billion by 2028 as more and more biologics lose critical patent, regulatory, and market exclusivity. Growing market interest in biosimilars in 2024 was also marked by significant regulatory, legal, and commercial developments concerning biologics and biosimilars. 

Here, we review developments from 2024 in the biologics and biosimilars space, including FDA approvals, new biosimilar launches, Biologics Price Competition and Innovation Act (BPCIA) litigation and other litigation implicating biologics, post-grant challenges against biologic patents, and biologics-related legislative and regulatory developments.

I. Biosimilar approvals and launches 

In the nearly 10 that have passed since FDA approved the very first biosimilars, the U.S. biosimilars market has experienced steady growth year after year. The trend continued through 2024, with the biosimilars market showing no signs of slowing down. 

In 2024, FDA broke its record for annual original Biologics License Application (BLA) approvals by authorizing 18 new biosimilars referencing eight different molecules:

• Five biosimilars of Regeneron’s Eylea® (aflibercept): Opuviz™ (Samsung Bioepis), Yesafili™ (Biocon), Ahzantive® (Formycon and Klinge), Enzeevu™ (Sandoz), and Pavblu™ (Amgen)
• Two biosimilars of Alexion’s Soliris® (eculizumab): Bkemv™ (Amgen) and Epysqli® (Samsung Bioepis and Teva)
• Biosimilars of Amgen’s Prolia® and Xgeva® (denosumab): Jubbonti® and Wyost® (Sandoz) 
• Six biosimilars of Johnson & Johnson’s Stelara® (ustekinumab): Selarsdi™ (Alvotech and Teva), Pyzchiva® (Sandoz and Samsung Bioepis), Otulfi™ (Fresenius Kabi and Formycon), Imuldosa™ (Accord), Yesintek™ (Biocon), and Steqeyma® (Celltrion)
• A biosimilar of Genentech’s Actemra® (tocilizumab): Tyenne® (Fresenius Kabi)
• A biosimilar of AbbVie’s Humira® (adalimumab): Simlandi® (Alvotech and Teva)
• A biosimilar of Genentech’s Herceptin® (trastuzumab): Hercessi™ (Henlius and Accord)
• A biosimilar of Amgen’s Neupogen® (filgrastim): Nypozi™ (Tanvex)

Several of these biosimilars were notable as the first approvals in their class. Jubbonti® and Wyost® were the first biosimilars referencing Prolia® and Xgeva® (denosumab), approved and designated as interchangeable for treatment of osteoporosis and to prevent bone-related complications caused by cancer. Yesafili™ and Opuviz™ were the first FDA-approved biosimilars of Eylea® (aflibercept), both approved and designated as interchangeable for the treatment of neovascular age-related macular degeneration, macular edema following retinal vein occlusion, diabetic macular edema, and diabetic retinopathy. Bkemv™ was the first Soliris® (eculizumab) biosimilar, approved and designated as interchangeable for the treatment of rare hematological diseases paroxysmal hemoglobinuria and atypical hemolytic uremic syndrome. 

The U.S. biosimilars market also saw five new product launches in 2024. Two of these newly launched products — Simlandi®, referencing Humira® (adalimumab), and Hercessi™, referencing Herceptin® (trastuzumab) — were latecomers entering crowded “first wave” biosimilar markets. The other three — Tofidence™ and Tyenne® for Actemra® (tocilizumab) and Pavblu™ for Eylea® (aflibercept) — were the first commercially available biosimilars for their respective reference products. 

Figure 1. Annual Biosimilar Approvals and Launches

As of the end of 2024, FDA has approved a grand total of 63 biosimilars across 17 unique reference products, with many biosimilar products competing against the same reference product. Of the 63 FDA-approved biosimilar products, 43 biosimilars have launched in the U.S. 

Figure 2. Biosimilar Approvals and Launches by Reference Product

The biosimilars pipeline maintained the momentum of 2023 throughout 2024. FDA reports that as of Q4 of Fiscal Year 2024,^I there were 109 biosimilar development programs enrolled in its Biosimilar Biological Product Development program, slightly up from the 101 biosimilar development programs enrolled in 2023. Table 1 summarizes publicly available information for a few exemplary biosimilars pending before FDA as of publication: 

Table 1. Exemplary Pending Biosimilar BLAsⁱⁱ

II. BPCIA litigation 

We start by summarizing overall statistics from BPCIA District Court litigation to date. Then we review ongoing and resolved BPCIA District Court cases from 2024. 

Since the BPCIA’s enactment in 2010, District Courts have handled over 65 BPCIA cases. Several of these cases are related, involving the same parties and the same biosimilar products. Early BPCIA litigation activity saw a peak of 12 cases filed in 2018, followed by a sharp drop to three cases filed in 2021. (Fig. 3.) These cases all involved biosimilars directed to the same nine reference products — Epogen®, Neupogen®, Rituxan®, Remicade®, Herceptin®, Enbrel®, Neulasta®, Humira®, and Avastin® — and are often referred to collectively as the “first wave” of biosimilar litigations. BPCIA litigation has shifted to the “second wave” of lawsuits focused on newer reference products initially approved by FDA between 2004 and 2011 — Tysabri®, Soliris®, Stelara®, Prolia® and Xgeva®, Actemra®, and Eylea®. The second wave began around 2022 and continued through 2024. Of the 19 BPCIA litigations filed since the beginning of 2022, 17 concern these newer reference products, while only two have involved a biosimilar of one of the nine older reference products. Fifteen of the BPCIA litigations involving the newer second wave reference products were pending during 2024, and 12 of those cases remain pending as of publication. 

Figure 3. BPCIA Cases Filed by Year Since BPCIA Enactment

Eight new BPCIA cases were filed in 2024. Four of these cases concern biosimilars of Prolia® and Xgeva® (denosumab), three concern biosimilars of Eylea® (aflibercept), and one concerns a biosimilar of Soliris® (eculizumab). Six of these cases, as well as four cases filed in 2023 and two cases filed in 2022, remain pending as of publication. 

BPCIA cases filed in 2024 continued to reflect noteworthy trends in patent dance behavior that emerged in the last few years. Before 2022, BPCIA participants tended to participate in the full extent of the dance. (Fig. 4.) Participants began to shift their behavior starting in 2022. Since then, parties have increasingly opted to engage in only the first few steps of the dance (if at all) rather than the full dance. These partial dances have been prompted by both reference product sponsors and biosimilar developers. 

Figure 4. Extent of Parties’ Participation in Patent Dance, 2018–2024

Below is a brief discussion of the BPCIA litigations in 2024. 

Tysabri® (natalizumab) litigation 

Biogen brought a BPCIA suit in September 2022 against Sandoz and its development partner Polpharma related to Sandoz’s natalizumab biosimilar Tyruko®, originally alleging infringement of 28 patents. Biogen Inc. v. Sandoz Inc., No. 1:22-cv-01190 (D. Del.). Today only five patents remain at issue following Biogen’s narrowing of asserted claims and patents in January 2025, as required by the scheduling order. Id. at Dkt. 491, 517. 

Polpharma had previously sought dismissal, arguing that it was not a “submitter” subject to suit under the BPCIA, Biogen failed to adequately allege that Polpharma’s future commercial activity would infringe following FDA approval, and any allegedly infringing acts fell within the statutory safe harbor. On March 5, 2024, the court denied Polpharma’s motion. Id. at Dkt. 363. The court found that Polpharma qualifies as a “submitter” of the BLA because it was “actively involved in the preparation of” and “stands to benefit from the submission and approval of” the BLA. Id. at 4–7. The court also found that Biogen adequately alleged future acts of infringement based on Polpharma’s collaboration with Sandoz to manufacture, market, and sell the natalizumab biosimilar if FDA approves Sandoz’s BLA, as well as Polpharma’s submission of an application to FDA for an allegedly infringing assay used to monitor patients during treatment with natalizumab. Id. at 2–3, 8–9. On the safe harbor defense, the court found that although Polpharma’s use of Biogen’s patented assay to obtain approval for Polpharma’s competing assay is protected by the § 271(e)(1) regulatory safe harbor, Polpharma’s use of Biogen’s patented assay during clinical trials for the defendants’ natalizumab biosimilar falls within the “research tools” exception and is therefore not covered by the safe harbor. Id. at 2–3, 9–12. 

On July 12, 2024, after holding a Markman hearing, the court issued a claim construction order, construing 13 claim terms in the asserted patents. The court adopted three agreed-upon constructions, four constructions proposed by Biogen, three constructions proposed by Sandoz and Polpharma, and three of the court’s own constructions. Id. at Dkt. 412, 430-1. 

Expert discovery is underway. A five-day bench trial is scheduled for May 5, 2025. Id. at Dkt. 491. 

Eylea® (aflibercept) litigations 

Regeneron has brought eight BPCIA lawsuits concerning biosimilars to Eylea® (aflibercept) against six biosimilar companies — Celltrion, Samsung Bioepis, Amgen, Biocon (formerly Mylan in this litigation), Formycon, and Sandoz. Before the litigation commenced, the biosimilar defendants varied in the extent of their participation in the patent dance. In the Celltrion, Mylan, and Amgen cases, the parties completed the full patent dance. Although the details are unclear due to heavily redacted complaints, it appears that in the Samsung Bioepis and Formycon cases the parties likely engaged in some, but not all, steps of the patent dance. And in the Sandoz case, the parties did not dance at all. 

Since our 2023 update, the U.S. Judicial Panel on Multidistrict Litigation consolidated all then-pending aflibercept cases in front of Judge Kleeh in the Northern District of West Virginia for pretrial proceedings. In re: Aflibercept Patent Litigation, No. 1:24-md-03103 (N.D. W. Va.). This is the first multidistrict litigation (MDL) of a BPCIA case, and we can expect more to come, as discussed with regard to Prolia® and Xgeva® (denosumab) below. 

Prior to MDL consolidation, Regeneron’s aflibercept litigation against Biocon went to trial in late 2023 before Judge Kleeh. Regeneron Pharms., Inc. v. Mylan Pharms. Inc., No. 1:22-cv-00061 (N.D.W. Va.). The court issued findings of fact and conclusions of law in Regeneron’s favor at the end of December 2023. Id. at Dkt. 692. 

In 2024, the court issued orders on Regeneron’s motions for a permanent injunction against Biocon and preliminary injunctions against Samsung Bioepis, Formycon, Celltrion, and Amgen. Each decision was based on Regeneron’s U.S. Patent No. 11,084,865 (the ’865 patent) purportedly covering Regeneron’s commercial formulation of Eylea®. Judge Kleeh granted preliminary injunctions against Biocon, Samsung Bioepis, Formycon, and Celltrion in June 2024. MDL Dkt. 188, 194, 247, 248. In September 2024, the court denied Regeneron’s preliminary injunction motion against Amgen based on Regeneron’s failure to show a likelihood of infringement of the ’865 patent. MDL Dkt. 352. Soon after the court’s decision, in October 2024, Amgen launched its aflibercept biosimilar, Pavblu™. Each of these decisions was appealed to the Federal Circuit. See Biocon’s Appeal No. 24-2002; Celltrion’s Appeal Nos. 24-2058 and 24-2147; Samsung Bioepis’s Appeal Nos. 24-1965, 24-1966, 24-2082, and 24-2083; Formycon’s appeal Nos. 24-2009, 24-2019, and 24-2156; and Regeneron’s Appeal No. 24-2351. The Federal Circuit granted various parties’ requests to expedite the appeals. As a result, the Federal Circuit heard oral argument in the Samsung Bioepis and Formycon appeals in December 2024, the Amgen appeal brought by Regeneron in January 2025, and the Celltrion and Biocon appeals on February 7, 2025. On January 29, 2025, the Federal Circuit affirmed the decisions in the Samsung Bioepis and Formycon appeals. 

Regeneron also filed an eighth BPCIA complaint related to Sandoz’s Eylea® (aflibercept) biosimilar Enzeevu™ in August 2024, alleging infringement of 46 patents. Regeneron Pharms., Inc. v. Sandoz Inc., No. 2:24-cv-08760 (D.N.J.). Shortly after Regeneron sued, the case was transferred to the Northern District of West Virginia under the MDL for coordinated and consolidated pretrial proceedings along with the other pending aflibercept cases before Judge Kleeh. See id. at Dkt. 8. In October 2024, Sandoz filed its answer and counterclaims, MDL Dkt. 381 (sealed), and Regeneron moved to strike and dismiss certain of Sandoz’s inequitable conduct affirmative defenses and counterclaims. MDL Dkt. 434. Briefing on Regeneron’s motion is ongoing. 

Prolia® and Xgeva® (denosumab) litigations 

Following Amgen’s now-closed case against Sandoz, there were four other BPCIA litigations brought by Amgen against biosimilar developers — Celltrion, Samsung Bioepis, Fresenius Kabi, and Accord — each seeking to market their biosimilar versions of Prolia® and Xgeva® (denosumab). In each case, the parties engaged in some, but not all, steps of the patent dance. 

These cases followed Amgen’s earlier litigation against Sandoz, Amgen Inc. v. Sandoz Inc., No. 2:23-cv-02406 (D.N.J.), which ended in 2024. In May 2023, Amgen filed its complaint against Sandoz’s denosumab biosimilar products Jubbonti® and Wyost® (previously known as GP2411), alleging infringement of 21 patents related to denosumab, including methods of manufacturing denosumab and denosumab products. Preliminary injunction proceedings were underway from fall 2023 through spring 2024, with a hearing set for April 29, 2024. The morning of the hearing, the parties announced a settlement. According to the parties’ stipulated order and injunction, the parties agreed that the asserted claims of Amgen’s U.S. Patent No. 7,364,736, which court filings indicate cover the denosumab antibody, are valid, enforceable, and infringed by Sandoz’s biosimilar. The parties further asked the court to enter an injunction prohibiting Sandoz from “making, using, selling, offering to sell or importing” its denosumab biosimilar products in the U.S.  until February 19, 2025. Dkt. 437 at 1–3. Although the specific terms of the agreement remain confidential, the parties publicly disclosed that Sandoz will be permitted to launch its denosumab biosimilar products no later than May 31, 2025. 

Amgen filed its cases against Celltrion and Samsung Bioepis in the District of New Jersey in May and August 2024, respectively. Amgen Inc. v. Celltrion, Inc., No. 1:24-cv-06497 (D.N.J.); Amgen Inc. v. Samsung Bioepis Co., No. 1:24-cv-08417 (D.N.J.). Amgen asserted 29 patents against Celltrion and 34 patents against Samsung Bioepis. The court issued scheduling orders in both cases. Trial in Amgen’s case against Celltrion was set for April 7, 2025, but on January 23, 2025, the parties filed a consent judgment and injunction allowing Celltrion to launch on June 1, 2025 — the day after Sandoz’s agreed-upon launch date. No trial date has been set for Amgen’s case against Samsung Bioepis; under the current schedule, Amgen must make a determination as to an expedited trial and/or preliminary injunction proceedings by February 14, 2025, and likely did so, but as of this writing that letter is sealed. 

Amgen filed its BPCIA complaint against Fresenius Kabi in the Northern District of Illinois in October 2024, alleging infringement of 33 patents. Amgen Inc. v. Fresenius Kabi USA, LLC, No. 1:24-cv-09555 (N.D. Ill.). No trial date has been set. 

Amgen brought its most recently filed denosumab-related BPCIA litigation against Accord in the Eastern District of North Carolina in November 2024. Amgen Inc. v. Accord Biopharma, Inc., No. 5:24-cv-00642 (E.D.N.C.). In its complaint, Amgen alleged infringement of 34 patents. Accord answered on January 10, 2025. On January 16, 2025, the court ordered the parties’ consent injunction prohibiting Accord from making, using, selling, offering to sell in the U.S, and/or importing into the U.S. its proposed biosimilar product before October 1, 2025. 

In November 2024, Amgen filed a motion for consolidation and transfer with the MDL Panel. Amgen’s motion requests consolidation of the four pending BPCIA litigations for coordinated pretrial proceedings in the District of New Jersey before Judge O’Hearn. On February 6, 2025, the MDL Panel granted the motion. 

Rituxan® (rituximab) litigation  

In November 2023, Genentech filed its sixth BPCIA suit related to its Rituxan® (rituximab) product, against Dr. Reddy’s Laboratories (DRL) and Fresenius Kabi’s DRL RI. Genentech, Inc. v. Dr. Reddy’s Labys., Inc. et al., No. 1:23-cv-22485 (D.N.J.). In the complaint, Genentech asserted 15 patents relating to the manufacture and use of Rituxan®, including six that had been previously asserted against other rituximab biosimilar developers. Id. at Dkt. 1 ¶ 5. The complaint also alleges that while it did provide its BLA to Genentech, DRL did not provide other manufacturing information Genentech requested. Id. ¶¶ 70–71. Genentech’s complaint goes on to explain that Genentech served defendants with the 3(A) list of patents and defendants provided a notice of commercial marketing a month and a half later. Id. ¶¶ 71–72. It appears that the parties did not exchange detailed statements concerning infringement and validity of the listed patents under § 262(l)(3)(B)–(C). In April 2024, before the defendants responded to Genentech’s complaint, the parties entered into a settlement agreement and jointly dismissed the case. Id. at Dkt. 38. The terms of the settlement agreement are not public. 

Soliris® (eculizumab) litigation 

In January 2024, Alexion filed a complaint related to Samsung Bioepis’ eculizumab biosimilar Epysqli®, asserting six patents related to eculizumab, compositions containing eculizumab, and methods for its therapeutic use. Alexion Pharms., Inc. v. Samsung Bioepis Co., No. 1:24-cv-00005 (D. Del.). Before the lawsuit commenced, Samsung Bioepis provided Alexion a notice of commercial marketing and stated that it did not intend to provide Alexion a copy of its BLA or manufacturing information under § 262(l)(2)(A). Id. at Dkt. 1 ¶¶ 23–25. The parties therefore did not engage in the patent dance. 

In February 2024, Alexion filed a motion for preliminary injunction based on infringement of U.S. Patent No. 9,447,176 (the ’176 patent) concerning methods of treating atypical hemolytic uremic syndrome and U.S. Patent No. 10,590,189 (the ’189 patent), concerning methods of treating paroxysmal nocturnal hemoglobinuria. Alexion Pharms., Inc. v. Samsung Bioepis Co., No. CV 24-5-GBW, 2024 WL 2111988, at *1 (D. Del. May 6, 2024). In May 2024, the court denied Alexion’s motion, finding that Alexion had failed to demonstrate a likelihood of success on the merits with respect to validity of both asserted claims Id. at *2–4. The court found that Samsung Bioepis’ obviousness and anticipation theories raised a substantial question of validity with respect to the ’176 patent, and the PTAB’s institution of Samsung Bioepis’ related inter partes review (IPR) against the ’189 patent raised a substantial question of validity as to that patent. Id. at *1–3. 

Alexion appealed the court’s order and filed an emergency motion in the District Court for an injunction pending appeal and a temporary restraining order pending resolution of the motion. Dkt. 60. The District Court denied Alexion’s emergency motion in June 2024, finding that it constituted a motion for reconsideration and that Alexion had failed to show that the court clearly erred and abused its discretion in denying Alexion’s motion for preliminary injunction. Dkt. 77. Alexion also filed a motion with the Federal Circuit for an injunction pending resolution of the appeal, which the court denied in July 2024. Appeal. No. 24-1829 Doc. 25. 

In August 2024, the parties settled and filed voluntary dismissals in the District Court and the Federal Circuit. The precise terms of the parties’ agreement are not public. Alexion’s case against Samsung Bioepis is to date the only BPCIA litigation related to a Soliris® biosimilar. Prior to the Samsung Bioepis litigation, Alexion had entered into a settlement agreement outside of litigation with Amgen granting Amgen a licensed entry date for its biosimilar Bkemv™ starting on March 1, 2025. There are currently no other publicly disclosed pending BLAs for additional Soliris® biosimilars.

III. Post-grant challenges to biologics 

Biologic and biosimilar activity at the Patent Trial and Appeal Board (PTAB) in 2024 was down compared to 2023, with 11 IPR petitions and no post-grant review (PGR) petitions filed, compared to 22 IPR petitions and two PGR petitions filed in 2023. Particularly notable was the fact that eight of the IPRs related to a single biologic, Merck’s Keytruda® (pembrolizumab), discussed in more detail below. IPR filings on biologics overall have leveled out significantly since 2017’s record high of 87 IPR petitions filed.

Figure 5. Biologic IPR Petitions Filed by Year

We discuss exemplary filings and developments briefly below. 

Eylea® (aflibercept) / Zaltrap® (ziv-aflibercept)

Regeneron’s fight at the U.S. Patent and Trademark Office (USPTO) over its aflibercept patents nearly came to an end in 2024, with eight of its patents found as being either unpatentable by the PTAB or statutorily disclaimed by Regeneron. After Mylan successfully invalidated U.S. Patent Nos. 9,669,069 and 9,254,338 (IPR2021-00880, 881) in November 2022 (joined by Apotex and Celltrion), the parties voluntarily dismissed the appeals in July 2024 (Fed. Cir. Nos. 23-1395, 23-1396). 

Similarly, after Mylan prevailed again and invalidated U.S. Patent Nos. 10,130,681 and 10,888,601 (IPR2022-01225, 1226) in January 2024 (joined by Celltrion and Samsung Bioepis), the parties voluntarily dismissed the appeals in August 2024 (Fed. Cir. Nos. 24-1564, 24-1567). These actions led to the termination of the other pending independent petitions filed by Samsung Bioepis challenging the ’681 patent and the ’601 patent (IPR2023-00442, 566), the latter of which Biocon had joined. 

Regeneron further terminated seven patent challenges filed against four other aflibercept patents (U.S. Patent Nos. 10,464,992, 10,857,205, 11,253,572, and 10,406,226) by Mylan, Celltrion, Samsung Bioepis, and Biocon by filing statutory disclaimers (IPR2023-00099, 462, 620, 884, 1312; IPR2024-00260, 298). 

In November 2024, Samsung Bioepis brought another challenge against a previously unchallenged aflibercept patent, U.S. Patent No. 11,084,865 (IPR2025-00176). Formycon shortly followed with a follow-on petition and motion for joinder (IPR2025-00233). The ’865 patent relates to a formulation including a VEGF antagonist that stays in native conformation following storage at 5oC for two months. As noted above, this patent is currently asserted in proceedings against Samsung Bioepis, Formycon, and Celltrion, along with other aflibercept biosimilars, in BPCIA litigation in the Northern District of West Virginia. An institution decision is expected by June 2025. Shortly before publication, Celltrion filed a separate petition challenging the ’865 patent (IPR2025-00456). 

Keytruda® (pembrolizumab) 

In November 2023 and March 2024, Merck filed IPRs challenging nine patents held by The Johns Hopkins University (JHU) directed to methods of treating microsatellite instability high or DNA mismatch repair deficient cancer with pembrolizumab (U.S. Patent Nos. 11,591,393, 10,934,356, 11,325,974, 11,325,975, 11,339,219, 11,649,287, 11,643,462, 11,629,187, and 11,643,491, in IPR2024-00240, 622, 623, 624, 625, 647, 653, 656, 650). The PTAB instituted the ’393 patent proceeding in June 2024 and the other eight proceedings in September 2024. Merck previously filed a declaratory judgment action in November 2022 in the District of Maryland asserting claims of non-infringement, as well as breach of contract (1:22-cv-03059 D. Md., Dkt. 1). JHU counter-claimed for infringement (Dkt. 15). Following institution of the ’393 patent proceeding, the District Court judge stayed the pending litigation in view of the institution decision. Final written decisions in the IPR proceedings are expected by June 2025 and September–October 2025. 

Stelara® (ustekinumab) 

In June 2023, Samsung Bioepis filed an IPR challenging Janssen’s U.S. Patent No. 10,961,307 relating to a method of treatment using ustekinumab (IPR2023-01103). A few months later the parties reached a settlement and terminated the IPR. Under the settlement agreement, Samsung Bioepis will be permitted to begin marketing its proposed biosimilar of Stelara®, Pyzchiva®, in the U.S. on February 22, 2025. In November 2023, Biocon filed a follow-on IPR challenging the ’307 patent, relying on the same prior art grounds and arguments as Samsung Bioepis’ petition (IPR2023-01444). Janssen subsequently settled with Biocon before the PTAB’s institution decision. Under that settlement agreement, Biocon will be permitted to market its Stelara® biosimilar, Yesintek™, the same day as Samsung Bioepis in 2025.

IV. Antitrust litigation concerning biologics and biosimilars 

The biologics market has undergone rapid growth in recent years, and with it, concerns of rising drug prices caused by allegedly anticompetitive evergreening tactics and related patent abuses. Last year saw developments in antitrust litigation concerning biologics, most notably related to Johnson & Johnson’s Stelara® (ustekinumab) and Amgen’s Enbrel® (etanercept), which have been the targets of state and federal antitrust claims. 

Stelara® (ustekinumab) antitrust litigation 

In December 2023, Carefirst of Maryland and other health insurers and independent licensees of the Blue Cross Blue Shield Association filed a class action antitrust complaint against Johnson & Johnson and Janssen alleging that the drugmakers were delaying ustekinumab biosimilar competition through a “scheme” to “unlawfully prolong patent protection for Stelara®” beyond the September 2023 expiration date of their key composition patent on ustekinumab. Carefirst of Maryland, Inc. v. Johnson & Johnson, No. 2:23-cv-00629 (E.D. Va.). In particular, the complaint alleges that the defendants violated Section 2 of the Sherman Act by (a) defrauding the USPTO into incorrectly issuing a method-of-use patent for ustekinumab, (b) acquiring certain patents covering biosimilar manufacturing technologies from Momenta, and (c) enforcing those patents to prevent or delay biosimilar competition. The complaint also asserts state law antitrust, consumer protection, and unjust enrichment claims. 

The defendants moved to dismiss the complaint, and in August 2024, the court granted in part and denied in part the motion, allowing the plaintiffs’ federal antitrust and state consumer protection claims to proceed. See, e.g., Carefirst of Maryland, Inc. v. Johnson & Johnson, No. 2:23-CV-629, 2024 WL 3858249 (E.D. Va. Aug. 16, 2024). The court also dismissed certain of Carefirst’s state antitrust and unjust enrichment claims. Id. On the federal claims, the court determined that the plaintiffs sufficiently alleged that J&J and Janssen had monopoly power in the U.S. ustekinumab market at all relevant times. Id. at *4. The court also found each of the three main components of the defendants’ alleged scheme could constitute anticompetitive conduct. The court further found that the complaint sufficiently alleged that defendants’ actions delayed biosimilar entry into the market, which resulted in higher prices for ustekinumab. Id. at *14. As for the state law claims, the court rejected the defendants’ arguments that the claims were preempted by federal patent law and determined on a state-by-state basis whether the plaintiffs had standing and sufficiently alleged the state claims. Id. at *16–*26.  

Enbrel® (etanercept) antitrust litigation 

In August 2024, Carefirst and other insurers filed another proposed class action, this time against Amgen. Carefirst of Maryland, Inc. v. Amgen, Inc., No. 2:24-cv-00484 (E.D. Va.). CareFirst challenged Amgen’s alleged “unlawful campaign to buttress and entrench its monopoly power over Enbrel” and thereby thwart biosimilar competition for its blockbuster biologic. Id. at Dkt. 1 ¶ 4. The plaintiffs alleged that in 2002, after Amgen acquired Immunex and the rights to Enbrel®, Enbrel® became and remains a “crown jewel” of Amgen’s portfolio, generating over $86 billion in worldwide sales. Id. ¶ 3. According to the complaint, Amgen’s patents on Enbrel® would likely have failed to prevent biosimilar competition beyond the 2015 expiration of the Immunex patents. The complaint further alleges that to extend its monopoly power, Amgen illegally acquired exclusive rights to patents related to Enbrel® held by its competitor Roche. Then, Amgen allegedly “weaponized” those Roche patents by asserting them against biosimilar competitors seeking to enter the market and strong-arming them into settlement agreements that would preclude entry in the U.S. market until 2029. Id. ¶ 10. The complaint asserts that Amgen’s actions have resulted in U.S. purchasers of etanercept overpaying “at least $3–4 billion to date.” Id. ¶ 13. 

After the plaintiffs amended the complaint, Amgen moved to dismiss, arguing that its conduct before the USPTO and federal courts was shielded from antitrust liability under the Noerr-Pennington doctrine and that the permanent injunctions issued by the District of New Jersey independently caused the alleged harm — i.e., lack of competing etanercept biosimilars. Id. at Dkt. 48 at 2–4. Before responding to Amgen’s motion, the plaintiffs filed a second amended complaint. Id. at Dkt. 52. On January 8, 2025, Amgen moved to dismiss the second amended complaint on similar grounds as before. Id. at Dkt. 55.

V. Biologic and biosimilar regulatory updates  

In 2024, FDA remained active in the biologics and biosimilars space by issuing industry guidance documents and rulemaking and furthering its efforts to support the development and approval of biologic and biosimilar products in the U.S. 

Biosimilar labeling 

In April, FDA issued draft guidance regarding Promotional Labeling and Advertising Considerations for Prescription Biological Reference Products, Biosimilar Products, and Interchangeable Biosimilar Products: Questions and Answers, replacing the draft guidance of February 2020 on the same issue. The guidance addresses questions pharmaceutical companies may have when developing their FDA-regulated promotional labeling and advertisements, including an example for interchangeable biosimilar products. The guidance aims to ensure that any promotional communications are accurate, truthful, and non-misleading, while also balanced in presenting information about a drug’s effectiveness and risks. FDA emphasized the importance of accurate statements on the safety and efficacy of drugs and reminded companies that biosimilar labels cannot state that their formulation is more effective than the reference product. Biosimilar manufacturers should also not imply on their labels that the biosimilar is a distinct product from the reference product. Further, advertising presenting clinical study data should refer to the biosimilar’s FDA-approved labeling and provide appropriate context. Lastly, any additional data presented in advertising communications must be consistent with the FDA-approved labeling and supported by appropriate scientific evidence. Pharmaceutical companies can request FDA review of draft promotional material before release. 

START Pilot Program 

In May, FDA announced a pilot program to help further accelerate the development of novel drug and biological products for rare diseases. FDA’s Center for Biologics Evaluation and Research (CBER) and its small molecule sister division, the Center for Drug Evaluation and Research, initiated the Support for clinical Trials Advancing Rare disease Therapeutics (START) Pilot Program. Pharmaceutical companies selected for the program will get frequent advice and enhanced communication from FDA to address program-specific development issues, such as those related to clinical study design, choice of control group, and product characterization. For CBER, eligible products must be a gene or cellular therapy intended to address an unmet medical need as a treatment for a serious rare disease or condition that is likely to lead to significant disability or death within the first decade of life. The CBER START program participants are Grace Science, LLC (GS-100 (AAV0-rhNGLY1)), ModernaTX (mRNA-3705), Myrtelle, Inc. (rAAV-Olig001-ASPA), and Neurogene, Inc. (NGN-401). FDA “hopes the insight gained will provide information on how best to facilitate more efficient development of potentially life-saving and life-changing therapies with rare disease indications.” Id. 

Interchangeability 

In June, heeding calls from Congress and bringing its position on interchangeable biosimilars in line with that of the European Medical Association, FDA issued a draft guidance for industry titled “Considerations in Demonstrating Interchangeability With a Reference Product: Update.” The guidance reverses FDA’s longstanding recommendation that biosimilar applicants submit switching studies to demonstrate that a biosimilar is interchangeable with its reference product. Citing experience gained from reviewing biosimilar and interchangeable biosimilar applications, improvements in analytical techniques, and its own systematic review and meta-analysis last year, FDA now proposes and seeks comment on a revised approach where switching studies will generally not be needed for interchangeability status. Under the updated guidance, applicants may now choose to provide, in lieu of a switching study, an “assessment” explaining how the clinical and comparative analytical data in the application shows that “the risk, in terms of safety and diminished efficacy, from . . . switching between the reference product and the proposed interchangeable product is not greater than the risk of using the reference product . . . without such switch.” The draft guidance further provides that biosimilar applicants with a pending BLA may submit an amendment including the interchangeability assessment. 

The Federal Trade Commission (FTC) issued a comment letter in August in support of FDA’s June 2024 draft guidance on interchangeability for biosimilars. FTC explained its interest in the draft guidance by highlighting that “[i]n healthcare markets, competition benefits patients by helping to: (1) control costs and prices; (2) improve quality of care; (3) promote innovation in products, services, and delivery models; and (4) expand access to healthcare goods and services.” FTC stated it believes FDA’s updated guidance on interchangeability would reduce the burden and associated cost of switching studies, which in turn would “lower barriers of entry, simplify the approval process, help to dispel the false impression of separate safety and efficacy standards for interchangeables and other biosimilars, and foster increased competition in biologic marketplaces.”  

Biosimilar manufacturing 

In July, FDA released “Postapproval Manufacturing Changes to Biosimilar and Interchangeable Biosimilar Products: Questions and Answers” providing guidance for the industry on managing post-approval manufacturing changes. This guidance aims to help manufacturers navigate regulatory requirements for post-approval changes, ensuring that biosimilar and interchangeable biosimilar products remain safe and effective for patients.

VI. Policy and legislation affecting biologics and biosimilars 

We turn next to policy and legislation affecting biosimilars. This year saw the first cycle of Centers for Medicare & Medicaid Services (CMS) drug price negotiations under the Inflation Reduction Act (IRA). Congress and the White House have proposed new legislation and policy initiatives in the space as well. 

Inflation Reduction Act 

The IRA, signed into law in August 2022, included several provisions aimed at reducing the cost of prescription medicines through the Medicare Drug Price Negotiation Program, a framework in which the Department of Health and Human Services (HHS) is permitted to negotiate with manufacturers on prices of certain drugs covered by Medicare. 

In August 2024, HHS published the results of the first Medicare drug price negotiations for 10 selected products, shown in Table 2 below. Three of the selected products were biologics: Enbrel® (etanercept), which lost reference product exclusivity in 2010; Stelara® (ustekinumab), which lost reference product exclusivity in 2021; and Novolog®/Fiasp® (insulin aspart), which lost reference product exclusivity in 2012. Of the three biologics, only Stelara® has a commercially available biosimilar. 

Table 2. Negotiated Prices for Initial Price Applicability Year 2026 Under Medicare Drug Price Negotiation Program 

This first round of negotiations saw the prices of nine of the 10 chosen medicines discounted by at least 50% compared to the 2023 list price. The new prices will be effective beginning January 1, 2026, for people with Medicare Part D prescription drug coverage. 

In January 2025, CMS announced the selection of 15 additional drugs covered under Medicare Part D for the second cycle of negotiations for drug prices that would be effective beginning in 2027. None of the 15 products in the second cycle are biologics. 

Beginning in 2023 and continuing through 2024, the IRA’s drug price negotiation program has faced numerous legal challenges by pharmaceutical companies, industry groups, and other stakeholders in federal courts across the country. The lawsuits have raised various claims that the program is unconstitutional and violates the Administrative Procedure Act (APA), including on the following alleged grounds:

• First Amendment. The IRA price negotiation provisions violate the First Amendment because they force manufacturers to enter into a pricing agreement with the Secretary of HHS that characterizes the negotiated prices as “fair,” which constitutes unlawful government-compelled speech. 
• Fifth Amendment. The IRA price negotiation program amounts to an unlawful taking without just compensation in violation of the Takings Clause and lacks adequate procedural safeguards, including notice, the opportunity to be heard, and availability of judicial review, in violation of the Due Process Clause. 
• Eighth Amendment. The IRA’s excise tax levied on drug manufacturers for non-compliance with the price negotiations constitutes an excessive fine in violation of the Eight Amendment. 
• Nondelegation doctrine. Congress improperly delegated to the Secretary of HHS the power to set drug prices under the IRA without providing an intelligible principle to guide its implementation. 
• Spending Clause. The IRA is not a valid spending condition and violates the Spending Clause because it does not condition receipt of federal funding on a manufacturer’s participation in program. Moreover, the IRA does not provide clear notice of the condition, the condition is not related to the purpose of the spending, it is unconstitutionally coercive, and it is in violation of the manufacturer’s constitutional rights. 
• APA. The IRA violates the APA because HHS issued rules to implement the law without notice and comment and HHS improperly expanded definitions and requirements for inclusion under law through published guidance. 

Thus far, the various challenges against the IRA have been unsuccessful, with District Courts uniformly ruling in favor of the government and upholding the Act. Many of the constitutional claims have turned on findings that participation in the drug price negotiation program, and Medicare as a whole, is voluntary. Litigation on the drug price negotiation program will continue to unfold through 2025, with appeals pending in a majority of the cases. 

Newly enacted and proposed legislation 

In the past few years, increasing access to and reducing the cost of prescription medicines has been a bipartisan focus of Congress. Last year was no different, with lawmakers considering several proposals relating to biologics and biosimilars concerning, among other issues, the number of patents asserted in BPCIA litigation, patent settlement agreements, and interchangeability. 

In July 2024, the Senate unanimously passed the Affordable Prescriptions for Patients Act (S. 150). If enacted, the bill would amend § 271(e) of the Patent Act to limit a reference product sponsor to asserting, in a BPCIA litigation, “a total of not more than 20 patents” that: (a) claim the biological product that is the subject of the BLA or a method or product used in the manufacture of such biological product; (b) are included on a reference product sponsor’s list of patents under 42 U.S.C. § 262(l)(3)(A); and (c) have a filing date of more than four years after the date the reference product was approved or that cover a manufacturing process not used by the reference product sponsor. A maximum of 10 of those patents may have issued after the reference product sponsor serves its 3A list. Notably, the bill does not limit the number of patents a reference product sponsor may assert that were filed earlier than or within four years of the reference product sponsor receiving FDA approval or that cover methods of treatment. Courts may increase this number in the interest of justice or for good cause, but the limits do not apply if the biosimilar applicant fails to comply with the patent dance. These proposed restrictions would be the only limitations on the number of patents that may be asserted by reference product sponsors against biosimilar applicants in BPCIA litigation. 

If enacted, the law could influence BPCIA litigation strategy. There are currently no limits on the number or types of patents that reference product sponsors may assert, and biosimilar applicants have faced upwards of 40 patents in BPCIA litigations. The bill’s proposed limitations may force more particularity in the number and types of patents reference product sponsors choose to assert. Additionally, because biosimilar applicants would not need to fight as many patents in litigation, the bill could reduce barriers to entry for biosimilars and increase competition in the market. Questions remain regarding the extent of any potential impacts of the Act given the narrow range of patents it impacts as well as frequent disputes between BPCIA litigants regarding whether the biosimilar applicant complied with the statute’s patent dance requirements. The bill is currently before the House of Representatives. As of publication, the House has not taken any action on this bill.  

In a similar vein, a bipartisan group of senators also introduced a “Bill to Address Patent Thickets” (S. 3583) in January 2024, which would amend §271(e) to limit plaintiffs to asserting one patent per “group” in an infringement action for a biologic. The draft legislation, if passed, would further limit the number of patents that reference product sponsors may assert in litigation, as a “group” would consist of two or more commonly owned patents or applications that “are identified on 1 or more disclaimers under section 253 to obviate obviousness-type patenting of another commonly owned patent” or “are subject to 1 or more disclaimers under section 253 to obviate obviousness-type double patenting of another commonly owned patent.” 

For several years, Congress has debated legislation that would amend the FTC Act to address so-called “reverse payment” patent settlement agreements by making such agreements presumptively illegal under antitrust law if a generic drug applicant or biosimilar applicant that was a party to the agreement received anything of value, excepting certain specific forms of compensation, and if the applicant agreed to limit or forgo research, development, marketing, or sales of the drug or biological product. The latest iteration is the Preserve Access to Affordable Generics and Biosimilars Act (S. 142). This bill authorizes FTC to initiate proceedings against “parties to any agreement resolving or settling a patent infringement claim in connection with the sale of a drug or biological product” and includes provisions that expressly allow for FTC to seek forfeiture and civil penalties against parties that enter into the prohibited settlement agreements. 

Two additional bills before Congress in 2024 that would potentially alter the landscape for patents on biologic drugs are the Promoting and Respecting Economically Vital American Innovation (PREVAIL) Act (S. 2220) and the Patent Eligibility Restoration Act (PERA) (S. 2140). The PREVAIL Act, introduced in 2023, would change post-grant proceedings before the USPTO, including by imposing a standing requirement on would-be patent challengers, limiting duplicative challenges against the same patents, and raising the burden of proof for proving invalidity of a challenged patent from a preponderance of the evidence to clear and convincing evidence. The bill moved to the Senate for a full vote after passing the Senate Judiciary Committee by an 11-10 vote at the end of November 2024. PERA, also introduced in 2023, would amend § 101 of the Patent Act to expressly eliminate the current judicially created exceptions to patent eligibility and replace them with certain express statutory exceptions. PERA was originally scheduled for a vote in the Senate Judiciary Committee in November 2024 along with the PREVAIL Act but was withdrawn from consideration before a vote was taken. Industry stakeholders have weighed in on the bills, with some, such as the trade group Association for Accessible Medicines, opposing the proposed legislation and asserting that the laws would make it more difficult for generic and biosimilar companies to challenge brand-name drug patent thickets and bring lower-cost medicines to patients. 

Several other bills that may affect the biologics and biosimilars landscape have been pending before Congress since 2023, and several have undergone multiple iterations over the years. This legislation includes: 

• The Biologics Competition Act of 2023 (H.R. 1790), which would direct the Secretary of HHS to evaluate the process by which interchangeable biological products are approved 
• The Increasing Access to Biosimilars Act of 2023 (H.R. 1352), which would require the Secretary of HHS to establish a voluntary three-year demonstration project to evaluate the benefits of providing a shared savings payment for future biosimilars covered by Medicare 
• The Interagency Patent Coordination and Improvement Act of 2023 (S. 79), which would establish an interagency task force between USPTO and FDA to share information and provide technical assistance for small molecule and biologic drug patents 
• The Prescription Pricing for the People Act of 2023 (S. 113), which would require FTC to report on anticompetitive practices and other trends within the pharmaceutical supply chain that may impact prescription drug costs  
• The Biosimilar Red Tape Elimination Act (S. 2305), which would eliminate certain requirements for a biosimilar to be deemed interchangeable  
• The Stop STALLING Act (S. 148), which would make it an unfair method of competition to submit an objectively baseless petition to FDA in an attempt to interfere with a competitor’s application for market approval of a drug or biologic product 

The U.S. biosimilars industry has continued to surge through 2024, with notable approvals by FDA, advancements streamlining regulatory approval processes, and continued interest by lawmakers in lowering barriers to biosimilar entry and adoption. Looking forward, the biosimilars market is likely to see significant change in 2025, with a number of new biosimilars referencing products such as Stelara® (ustekinumab), Soliris® (eculizumab), and Prolia® and Xgeva® (denosumab) expected to hit the market in the coming months. And it remains to be seen how Amgen’s at-risk launch of its Eylea® (aflibercept) biosimilar in October 2024 will affect, if at all, Regeneron’s decision to continue or settle its patent disputes with the other aflibercept biosimilar competitors. We will be monitoring these developments and expect an exciting year ahead for biologics and biosimilars. 

Appendix A: Biosimilars Approved as of 2024

Appendix B: Ongoing and Settled BPCIA Cases From 2024

ⁱ FDA’s fiscal year begins on October 1 and ends on September 30.

ⁱⁱ The information in Table 1 is based on publicly available information from biosimilar manufacturers and may not necessarily reflect the current status of each biosimilar.