FDA Approves Poherdy: First Interchangeable Biosimilar to Perjeta

The FDA has granted approval to Poherdy (pertuzumab-dpzb) injection, making it the first biosimilar approved for Perjeta (pertuzumab). Poherdy was also with interchangeability.¹ This approval, granted to the product developed by Shanghai Henlius Biotech and commercialized by Organon, signals the expansion of biosimilar competition into the HER2-positive breast cancer treatment landscape.

FDA approves Poherdy, the first interchangeable biosimilar for Perjeta, enhancing competition in HER2-positive breast cancer treatment. | image credit: gustavofrazao - stock.adobe.com

Rationale for Approval and Approved Indications

The FDA’s decision to approve Poherdy was based on a comprehensive review of scientific evidence demonstrating that the product is highly similar to Perjeta and possesses no clinically meaningful differences in terms of safety and effectiveness. The evidence package included a detailed analytical comparison utilizing an extensive battery of physicochemical tests and biological assays across multiple manufactured lots, confirming similarity in structural and functional features known to impact safety and efficacy.

Clinical data supporting the approval included results from a human pharmacokinetic (PK) similarity study in healthy adult participants, which confirmed similar exposure between Poherdy and Perjeta after a single intravenous infusion. Additionally, data from a study involving patients with early HER2-positive and HR-negative breast cancer in the neoadjuvant setting supported Poherdy's approval as an interchangeable biosimilar.

Poherdy is a HER2/neu receptor antagonist that targets subdomain II of HER2, working in concert with trastuzumab to augment antitumor activity. It was approved for all the same treatment indications currently approved for Perjeta in adults, including:

1. Use in combination with trastuzumab and docetaxel for HER2-positive metastatic breast cancer in adults who have not received prior anti-HER2 therapy or chemotherapy for metastatic disease
2. Use in combination with trastuzumab and chemotherapy as neoadjuvant treatment for adults with HER2-positive, locally advanced, inflammatory, or early-stage breast cancer (greater than 2 cm or node positive)
3. Use in combination with trastuzumab and chemotherapy as adjuvant treatment for adults with HER2-positive early breast cancer at high risk of recurrence.

Next Steps: Legal Battles and Market Dynamics

The approval of Poherdy thrusts its developers, Shanghai Henlius Biotech and Organon, into the familiar territory of patent litigation, mirroring patterns seen previously in the adalimumab, ustekinumab, and etanercept markets.²

Genentech and Hoffman-La Roche, the originators of Perjeta, have already filed the first patent infringement case concerning the pertuzumab biosimilar against Shanghai Henlius Biotech and Organon.³ The complaint, filed in the US District Court of New Jersey, alleges that the proposed biosimilar could reasonably infringe on 24 patents related to Perjeta. Genentech is seeking multiple forms of relief, including judgments of infringement, preliminary and/or permanent injunctions, and damages. Such litigation frequently leads to delayed market launches and prolonged monopolies.

The broader oncology landscape is gearing up for a significant wave of biosimilar competition, with the market opportunity expected to reach approximately $25 billion by 2029.² The success of new entrants like Poherdy will depend heavily on offering steep net price discounts to gain rapid payer and provider adoption, a strategy that drove successful uptake for earlier oncology biosimilars (referencing Herceptin, Rituximab, and Avastin).

Policy Ambiguity: Interchangeability and Draft Guidances

Poherdy's designation as the first interchangeable biosimilar for Perjeta carries significant policy weight, although its practical impact in oncology may be limited. Interchangeability allows for substitution at the pharmacy level without prescriber consultation, similar to generic drugs.⁴ However, laws regarding interchangeability have never restricted access to provider-administered biologics—which often includes many oncology treatments like Poherdy (an injection)—meaning patients receiving clinic-based therapies can already access biosimilars regardless of this status.

Meanwhile, policy surrounding biosimilar development and interchangeability remains in flux at the FDA level, with key draft guidances yet to be finalized.⁵ The FDA has released draft guidance suggesting that comparative efficacy studies may be waived for a biosimilar biologics license application if the product is analytically well-characterized, a move intended to trim development costs (estimated between $100 million and $300 million per program) and shorten timelines.

Similarly, updated draft guidance on interchangeability proposes removing the requirement for expensive switching studies, citing emerging scientific consensus that switching risk is insignificant.⁶ These unfinalized guidances create potential confusion for manufacturers as they plan their subsequent launches. Furthermore, while federal officials have expressed strong political support for considering all biosimilars interchangeable, state laws requiring specific prescriptions or banning automatic substitution create ambiguity about the immediate practical effect of this designation across the country.⁵

Remaining Challenges for Oncology Biosimilars

Despite the momentum generated by Poherdy's approval, the oncology biosimilar space faces several systemic challenges:²

1. The Biosimilar Void: A major long-term issue remains the "biosimilar void," where only about 10% of the biologics expected to lose patent protection between 2025 and 2034 have biosimilars in active development.⁷ This gap is driven by prolonged development timelines, manufacturing complexity, and limited return on investment for treatments targeting smaller patient populations.
2. Payer and PBM Influence: Even with lower list prices, the benefit of biosimilars may not reach patients due to prevailing rebate structures and reimbursement policies negotiated between pharmacy benefit managers (PBMs) and manufacturers.⁸ PBM policies often favor more expensive originator products, thereby inhibiting biosimilar uptake.
3. Originator Tactics: Reference product manufacturers often deploy lifecycle management tactics, such as winning approval for new routes of administration or new indications, to protect exclusivity and limit the scope of biosimilar extrapolation on labels.²
4. Geopolitical Uncertainty: The possibility of the US imposing tariffs on international pharmaceutical products and active pharmaceutical ingredients adds complexity, particularly since many biosimilars are developed by international companies.⁹

The successful entry of Poherdy into the US market is a step forward for competition in oncology, putting pressure on reference product manufacturers like Roche.¹ However, to realize the full potential of these treatments—including cost reductions and broader patient access—regulatory advancements must be paired with commercial reforms, litigation certainty, and stakeholder education to ensure long-term confidence in biosimilars.²

References

1. FDA approves first interchangeable biosimilar to Perjeta to treat certain types of breast cancer. FDA. November 13, 2025. Accessed November 13, 2025. https://www.fda.gov/drugs/news-events-human-drugs/fda-approves-first-interchangeable-biosimilar-perjeta-treat-certain-types-breast-cancer

2. Yadav P, Corridon C, Mathuria M. The next frontier: oncology biosimilars in 2025 and beyond. The Center for Biosimilars^®. January 13, 2025. Accessed November 18, 2025. https://www.centerforbiosimilars.com/view/the-next-frontier-oncology-biosimilars-in-2025-and-beyond

3. Genentech files first pertuzumab BPCIA complaint against Shanghai Henlius and Organon. Big Molecule Watch. August 18, 2025. Accessed November 18, 2025. https://www.jdsupra.com/legalnews/genentech-files-first-pertuzumab-bpcia-3305474/

4. Poore D. Breaking down biosimilar barriers: interchangeability. The Center for Biosimilars. November 14, 2024. Accessed November 18, 2025. https://www.centerforbiosimilars.com/view/breaking-down-biosimilar-barriers-interchangeability

5. Jeremias S. A closer look at new FDA guidance removing barriers to biosimilar development. The Center for Biosimilars. October 30, 2025. Accessed November 18, 2025. https://www.centerforbiosimilars.com/view/a-closer-look-at-new-fda-guidance-removing-barriers-to-biosimilar-development

6. Jeremias S. FDA draft guidance removes switching study requirements for biosimilar interchangeability. The Center for Biosimilars. June 20, 2024. Accessed November 18, 2025. https://www.centerforbiosimilars.com/view/fda-draft-guidance-removes-switching-study-requirements-for-biosimilar-interchangeability

7. Jeremias S. The biosimilar void: 90% of biologics coming off patent will lack biosimilars. The Center for Biosimilars. February 5, 2025. Accessed November 18, 2025. https://www.centerforbiosimilars.com/view/the-biosimilar-void-90-of-biologics-coming-off-patent-will-lack-biosimilars

8. Jeremias S. The age of adalimumab is upon us: how stakeholders can prepare. The Center for Biosimilars. June 28, 2023. Accessed November 18, 2025. https://www.centerforbiosimilars.com/view/the-age-of-adalimumab-is-upon-us-how-stakeholders-can-prepare

9. Jeremias S. The Trump administration’s drug price actions and why US prices are already sky-high. The Center for Biosimilars. May 17, 2025. Accessed November 18, 2025. https://www.centerforbiosimilars.com/view/the-trump-administration-s-drug-price-actions-and-why-us-prices-are-already-sky-high