On 19 June 2025, the Unified Patent Court (UPC) Court of Appeal issued decisions refusing two rehearing applications by Alexion Pharmaceuticals in proceedings it had brought seeking preliminary injunctions against Amgen and Samsung Bioepis in relation to the sale of their eculizumab biosimilars in the EU.  The result is that Amgen and Samsung Bioepis are free to continue selling their eculizumab biosimilars in the EU.

Alexion had originally filed the proceedings in the UPC against Samsung Bioepis and Amgen in March 2024, seeking preliminary injunctions for alleged infringement of EP 3 167 888 (method of treating paroxysmal nocturnal hemoglobinuria).  On 20 December 2024, the UPC Court of Appeal denied Alexion preliminary injunctions, upholding the earlier decisions of the Hamburg Local Division of the UPC, delivered on 26 June 2024

The UPC Court of Appeal refused Alexion’s rehearing applications on the basis that Alexion had not established that there was a fundamental procedural defect in the earlier decisions of the Court of Appeal.

Samsung Bioepis’ Epysqli® (SB12), biosimilar to Alexion’s Soliris® (eculizumab), was approved by the European Medicines Agency (EMA) on 30 May 2023 and was launched in Europe in 2023.  Amgen’s Bekemv® (eculizumab) was EMA approved in April 2023.

On 21 May 2025, Mr Justice Meade of the High Court of Justice for England and Wales delivered his decision in proceedings involving allegations of patent infringement by Alexion against each of Samsung Bioepis and Amgen, finding Alexion’s asserted patent (European Patent (UK) No. 3 167 888 B1) to be not infringed and invalid.

Samsung Bioepis and Amgen have both filed post-grant oppositions to Alexion’s EP 3 167 888.  Those oppositions are ongoing.

On 21 May 2025, Mr Justice Meade of the High Court of Justice for England and Wales delivered his decision in proceedings involving allegations of patent infringement by Alexion against each of Samsung Bioepis and Amgen, finding Alexion’s asserted patent to be not infringed and invalid.

Alexion alleged that Samsung Bioepis’ Epysqli® and Amgen’s Bekemv®, biosimilars to Alexion’s Soliris® (eculizumab), infringed European Patent (UK) No. 3 167 888 B1, granted on 1 May 2024.  The Court held there was no infringement on the basis that the relevant claims of the patent claimed a light chain antibody sequence which had 22 amino acids (a leader sequence) not present in eculizumab.  The Court further held that Alexion’s patent was invalid for obviousness/lack of inventive step.  It is not yet known whether Alexion will appeal the decision.

The UK judgment follows decisions of the UPC (June 2024) and the UPC Court of Appeal (December 2024), refusing to grant preliminary injunctions against Amgen and Samsung Bioepis in relation to the sale of their eculizumab biosimilars in the EU.

In contrast to the decision in the UK and Europe, less than two weeks ago, the Canadian Federal Court published a decision (issued on 28 April 2025 on a confidential basis) granting Alexion an injunction preventing the Canadian launch of Amgen’s Bkemv® until 15 March 2027.  This decision was based on the Court’s finding that claims 1 and 2 of Alexion’s Canadian patent no. 2645810 are valid and infringed by Amgen.

In the US, a class action complaint was filed in April 2025 by EmblemHealth, alleging that Alexion unlawfully delayed the introduction of biosimilar competition to Soliris® by misusing its patents.  That lawsuit followed the launch of Teva/Samsung Bioepis’ Epysqli® in April 2025 and Amgen’s Bkemv® in March 2025.  Both Samsung Bioepis (in August 2024) and Amgen (in May 2020) reached settlements with Alexion in relation to their US eculizumab biosimilars.

On 12 May 2025, the Canadian Federal Court published a decision (issued on 28 April 2025 on a confidential basis) granting Alexion an injunction preventing the Canadian launch of Amgen’s Bkemv®, biosimilar to Alexion’s Soliris® (eculizumab), until 15 March 2027.  The decision is based on the Court’s finding that claims 1 and 2 of Alexion’s Canadian patent no. 2645810 (which encompass eculizumab) are valid and infringed by Bkemv®.

Subject to any appeal, the injunction will remain in force until 15 March 2027, the date on which Alexion’s ‘810 patent expires.  The Court also ordered Amgen to deliver up to Alexion or destroy (at Alexion’s election) all eculizumab product (including any intermediates) that would breach the injunction.

The Canadian decision comes a month after a class action complaint was filed in the US by EmblemHealth, alleging that Alexion unlawfully delayed the introduction of biosimilar competition to Soliris® by misusing its patents.  That lawsuit followed the launch of two eculizumab biosimilars in the US: Teva/Samsung Bioepis’ Epysqli® in April 2025 and Amgen’s Bkemv® in March 2025.  Both Samsung Bioepis (in September 2024) and Amgen (in May 2020) reached settlements with Alexion in relation to their US eculizumab biosimilars.

On 16 April 2025, EmblemHealth, a US nonprofit health insurer, filed a class action complaint in the US District Court for the District of Massachusetts alleging that AstraZeneca subsidiary, Alexion Pharmaceuticals, has unlawfully delayed the introduction of biosimilar competition to Soliris® (eculizumab) by misusing its patents.

According to Emblem’s complaint, Alexion wrongly obtained new patents to block biosimilar versions of Soliris® for four years after its patents on the drug should have expired.  Emblem seeks compensation on behalf of US purchasers of eculizumab for “overpayments” they allegedly made (estimated to exceed USD 2 billion) during the four-year delay in biosimilar availability as well as an order ending Alexion’s “monopoly” on Soliris®.

The lawsuit follows the launch of two eculizumab biosimilars in the US: Teva/Samsung Bioepis’ Epysqli® on 7 April 2025 and Amgen’s Bkemv® in March 2025.  Both Samsung Bioepis (in September 2024) and Amgen (in May 2020) reached settlements with Alexion in relation to their eculizumab biosimilars.

On 7 April 2025, Teva and Samsung Bioepis announced the US launch of Epysqli® (eculizumab-aagh),  biosimilar to Alexion’s Soliris®.  According to the joint announcement, Epysqli® will be offered at a 30% discount of the Wholesale Acquisition Cost (WAC) of Soliris®.

This makes Epysqli® the second available eculizumab biosimilar in the US, following the launch of Amgen’s Bkemv® (eculizumab-aeeb) in March 2025.  The timing of the US launch of Bkemv® was governed by a settlement reached by Amgen and Alexion in May 2020, permitting launch from 1 March 2025.

Epysqli® was launched in Germany, Italy and Spain in October 2023 and in Korea in April 2024.  The UPC (June/July 2024) and the UPC Court of Appeal (December 2024) refused to grant preliminary injunctions against Samsung Bioepis and Amgen in relation to the sale of their eculizumab biosimilars in the EU.

On 5 March 2025, Generics Bulletin reported that Amgen has launched Bkemv® (eculizumab-aeeb) in the US as the first available interchangeable biosimilar to Alexion’s Soliris®.

Bkemv® was approved by the FDA in May 2024 for the same indications as Soliris® (atypical haemolytic uremic syndrome (aHUS) and paroxysmal nocturnal haemoglobinuria (PNH)), and in the same dosage form and strength.

The timing of the US launch of Bkemv® was governed by a settlement reached by Amgen and Alexion in May 2020, permitting launch from 1 March 2025.  The only other eculizumab biosimilar currently approved in the US is Samsung Bioepis’ Epysqli® (SB12) (approved July 2024).

Amgen’s eculizumab biosimilar was approved in the EU as Bekemv® in April 2023.  On 19 March 2024, Alexion filed proceedings against Amgen in the Unified Patents Court (UPC), seeking provisional measures in relation to alleged infringement of EP3167888, concerning a method of treating PNH using eculizumab.  The UPC (June/July 2024) and the UPC Court of Appeal (December 2024) refused to grant preliminary injunctions against Amgen (and Samsung Bioepis) in relation to the sale of their eculizumab biosimilars in the EU.

On 4 March 2025, NeurologyLive reported that the US FDA has approved an expanded indication of Alexion/AstraZeneca’s Soliris® (eculizumab) to include both adult and paediatric patients 6 years of age or older with generalised myasthenia gravis (gMG) who are antiacetylcholine receptor (AChR) antibody positive.

This approval means Soliris® (eculizumab) is the first and only approved treatment in the US for paediatric patients living with the gMG.

Soliris® was approved for the same indication in the EU in July 2023.

On 22 January 2025, Samsung Biologics revealed its Q4 and 2024 annual financial results, reporting full year 2024 consolidated revenue of over 4 trillion won (approx. USD2.78bn), a 23% increase compared to 2023.  According to the Korea Herald, this makes Samsung Biologics the first biotech company in South Korea to reach this sales milestone.

Samsung Biologics’ Q2/24 consolidated revenue was KRW 1.26 trillion, with operating profit of KRW 325.7 billion.

Samsung Biologic’s biosimilar subsidiary, Samsung Bioepis, achieved 2024 consolidated revenue of 1.537 trillion won, a 51% increase year on year.  Its operating profit more than doubled compared to 2024, at 435 billion won.

Biosimilar highlights for 2024 are reported to include the European launch (July 2024) and US FDA approval (July 2024) of SB17/Pyzchiva® (ustekinumab, biosimilar to J&J/Janssen’s Stelara®), the US approval (July 2024) of SB12/Epysqli™ (eculizumab, biosimilar to Alexion’s Soliris®), the European (November 2024) and US FDA approval (May 2024) of SB15/Opuviz® (aflibercept, biosimilar to Regeneron’s Eylea®), and the positive CHMP opinion (November 2024) for SB16/Obodence®/Xbryk® (denosumab, biosimilar to Amgen’s Prolia® and Xgeva®).

On 16 January 2025, Samsung Bioepis published its quarterly US Biosimilar Market Report.  The report has been released every quarter since April 2023 and details average sales price information for US launched biosimilars and market share and price trends.

The Q1/2025 edition reports that, as of December 2024, the FDA has approved 64 biosimilars across 17 unique biological molecules, with 41 of those biosimilars having launched in the US market.  In Q4/2024, three new ustekinumab biosimilars were approved in the US (Accord Healthcare/Meiji Seika Pharma’s Imuldosa® (Oct 2024), Biocon’s Yesintek® (Dec 2024) and Celltrion’s SteQeyma® (Dec 2024).

Samsung Bioepis reports that in 2025 the industry is “set to witness the launch of biosimilars in new therapeutic areas and for new molecules such as eculizumab, aflibercept, ustekinumab and denosumab”.

According to the report, on average, biosimilar launches have resulted in 53% market share in biosimilar markets and a 53% reduction in average sales price after 5 years of biosimilar competition.  The fastest uptake of biosimilars has to date occurred in oncology, ophthalmology and pegfilgrastim markets, while biosimilars in immunology, insulin glargine, filgrastim and epoetin alfa markets demonstrate slower uptake.

It is reported that, as of November 2024, the US adalimumab biosimilar market share reached 23% (up 1% since August 2024), with most gains coming from Sandoz’s Hyrimoz® and Organon’s Hadlima®.  The market share for biosimilars which have had a longer time on the market include 86% for trastuzumab and 90% for bevacizumab.

At the JP Morgan Annual Healthcare conference on 13 January 2025, Amgen revealed that it currently has an ocrelizumab biosimilar (ABP 692) in Phase 3 trials.  The Phase 3 study (NCT06700343), which begins enrolment this month in the US, is aimed at demonstrating pharmacokinetic and pharmacodynamic similarity between ABP 692 and Genentech’s Ocrevus® (ocrelizumab) in patients with relapsing, remitting multiple sclerosis.

Celltrion also has an ocrelizumab biosimilar in development, announcing in August 2023 that the European Medicines Agency (EMA) had partially approved its Phase 3 IND for CT-P53 (ocrelizumab).  Its study (NCT05906992), to be conducted in Poland, is currently recruiting.

Amgen has two further biosimilars in Phase 3 trials: pembrolizumab (Ph 3 in nsNSCLC initiated May 2024 for ABP 234) and nivolumab (patients enrolled in a study evaluating pharmacokinetic similarity of ABP 206 compared with BMS’ Opdivo® (nivolumab) in Q2/2024).

Amgen is expecting to launch its Wezlana®/ustekinumab (biosimilar to Janssen’s Stelara®) in the US in Q1/2025 and is planning a US-launch for Bkemv®/eculizumab (biosimilar to Alexion’s Soliris®) in Q2 2025.  Bkemv®’s US launch is subject to a settlement reached by Amgen and Alexion in May 2020.