Biosimilars News Roundup: August 2025

August 2025 proved to be another dynamic month for the biosimilar landscape, characterized by significant financial milestones, new product launches, reinforcing clinical data, and ongoing battles over market access. These developments underscore the growing impact of biosimilars on health care affordability and treatment options, even as persistent challenges continue to shape their adoption.

Financial Wins and Product Launches

The month concluded with Alvotech reporting a record-breaking first half of 2025, showcasing a remarkable financial turnaround.1 The Iceland-based biotech company swung from a $153.5 million net loss in the first half of 2024 to a net profit of $141.7 million for the same period in 2025. This success was largely fueled by a more than 200% year-on-year increase in product revenues, reaching $204.7 million, and marking the company's first-ever quarterly positive cash flow from operations.

Key drivers included the strong commercial performance of its high-concentration adalimumab biosimilar, Simlandi (marketed as Hukyndra in Europe), and its ustekinumab biosimilar, Selarsdi (Uzpruvo in Europe).

Selarsdi, which gained interchangeable status from the FDA in April 2025, achieved more than 20% of the overall Stelara market share in the US by July 2025. Alvotech is also advancing its pipeline, with biologics license applications for proposed denosumab and aflibercept biosimilars accepted by the FDA, and its aflibercept biosimilar, Mynzepli, recently secured European approval.

In other launch news, Accord BioPharma commercially launched Imuldosa (ustekinumab-srlf), its biosimilar to Stelara, approved for various indications including plaque psoriasis, psoriatic arthritis, Crohn disease, and ulcerative colitis.2 Accord BioPharma priced Imuldosa at the lowest wholesaler acquisition cost (WAC) among branded ustekinumab biosimilars and offered a $0 co-payment program for eligible patients, aiming to expand access to cost-effective biologic therapies.

Clinical Data Reinforce Biosimilar Equivalence and Safety

Several studies published in August bolstered the scientific evidence for biosimilars. A year-long phase 3 clinical trial in Poland confirmed the comparability of CT-P47, a tocilizumab biosimilar, to the reference product Actemra/RoActemra for rheumatoid arthritis (RA).3 The study demonstrated comparable efficacy, safety, and immunogenicity, even for patients who switched from the originator biologic, with consistent disease activity scores and no new safety concerns identified. This adds to the growing confidence in biosimilars for RA management, alongside other FDA-approved tocilizumab biosimilars like Tofidence and Tyenne.

Similarly, a phase 3 clinical trial showcased the equivalence of denosumab biosimilar LY01011 to the reference product Xgeva for treating bone metastases in solid tumors.4 LY01011 demonstrated similar efficacy in reducing bone metabolism biomarkers, comparable safety profiles, and a lack of unexpected adverse reactions across 850 patients. This evidence supports the use of denosumab biosimilars, such as Wyost/Jubbonti, which were approved in the US in March 2024. Long-term safety data also emerged for Sandoz’s biosimilar filgrastim.

A 10-year prospective follow-up of 244 healthy stem cell donors who received Zarzio (marketed as Filgrastim Hexal in Germany) reported no new safety concerns for hematopoietic stem and progenitor cell mobilization.5 While most donors experienced adverse events during initial mobilization, serious adverse events documented over the decade were not deemed related to the biosimilar filgrastim, and donors maintained superior physical health scores. This study reinforces the established safety profile of filgrastim biosimilars, including Zarxio (filgrastim-sndz), which was the first FDA-approved biosimilar in the US in 2015.

Furthermore, Canadian real-world evidence found comparable outcomes between etanercept biosimilars (Brenzys or Erelzi) and the originator, Enbrel, for patients with rheumatoid arthritis.6 The analysis revealed no significant differences in time to first remission or sustained remission rates, aligning with findings from randomized controlled trials and European registry data. This highlights the clinical interchangeability of these products, in stark contrast to the delayed market entry of etanercept biosimilars in the US due to ongoing patent litigation.

Battles Over Market Entry and Access Innovation

The ongoing challenge of patent disputes continues to affect biosimilar market entry. Genentech and Hoffman-La Roche initiated the first patent infringement case (BPCIA complaint) concerning a pertuzumab biosimilar, filing against Shanghai Henlius Biotech and Organon.2 The complaint alleges infringement of 24 patents related to Genentech’s originator, Perjeta, following a pattern of litigation that has previously delayed market launches for other biosimilars.

However, innovative strategies are emerging to enhance access. MedImpact Holdings announced plans to provide access to an unbranded ustekinumab-aekn biosimilar. This unbranded interchangeable biosimilar to Stelara is anticipated to be available at a significantly lower cost, aiming to bypass traditional supply chain costs, enhance price transparency, and reduce reliance on rebates, thus offering a more affordable treatment option for patients.

Despite the clear benefits, challenges in biosimilar adoption persisted. A comprehensive analysis of primary care prescribing data from 2020 to 2024 revealed that low prices failed to boost insulin glargine biosimilar uptake in the UK.7 Even after the MHRA declared all biosimilars interchangeable with their reference products in 2022, originator Lantus continued to dominate prescriptions and, by 2024, became the least expensive option in all 4 UK nations.

Biosimilars like Abasaglar and Semglee achieved only modest market shares (eg, 24% in England and Scotland, 5% in Northern Ireland, 11% in Wales). Key barriers identified include Lantus's price reductions, prescriber inertia, and national prescribing guidelines that require prescribers to initiate brand switching.

References

1. Jeremias S. Alvotech reports record-breaking first half of 2025 amid strong biosimilar sales. The Center for Biosimilars®. August 27, 2025. Accessed September 2, 2025. https://www.centerforbiosimilars.com/view/alvotech-reports-record-breaking-first-half-of-2025-amid-strong-biosimilar-sales

2. Jeremias S. Litigation, launch, and lower costs: 3 big moves in the US biosimilar space. The Center for Biosimilars. August 19, 2025. Accessed September 2, 2025. https://www.centerforbiosimilars.com/view/litigation-launch-and-lower-costs-3-big-moves-in-the-us-biosimilar-space

3. Jeremias S. Year-long phase 3 study confirms tocilizumab biosimilar comparability with Actemra. The Center for Biosimilars. August 6, 2025. Accessed September 2, 2025. https://www.centerforbiosimilars.com/view/year-long-phase-3-study-confirms-tocilizumab-biosimilar-comparability-with-actemra

4. Santoro C. Denosumab biosimilar LY01011 shows equivalence to reference product for bone metastases. The Center for Biosimilars. August 14, 2025. Accessed September 2, 2025. https://www.centerforbiosimilars.com/view/denosumab-biosimilar-ly01011-shows-equivalence-to-reference-product-for-bone-metastases

5. Jeremias S. Ten years of data support the safety of biosimilar filgrastim for donor mobilization. The Center for Biosimilars. August 22, 2025. Accessed September 2, 2025. https://www.centerforbiosimilars.com/view/ten-years-of-data-support-safety-of-biosimilar-filgrastim-for-donor-mobilization

6. Jeremias S. Canadian RWE shows comparable outcomes between etanercept biosimilars, originator. The Center for Biosimilars. August 26, 2025. Accessed September 2, 2025. https://www.centerforbiosimilars.com/view/canadian-rwe-show-comparable-outcomes-between-etanercept-biosimilars-originator

7. Jeremias S. Low prices fail to boost insulin biosimilar uptake in the UK. The Center for Biosimilars. August 11, 2025. Accessed September 2, 2025. https://www.centerforbiosimilars.com/view/low-prices-fail-to-boost-insulin-biosimilar-uptake-in-the-uk