Prestige posts positive Phase 3 data for Avastin biosimilar HD204

CURRENT FULL VERSION: Prestige Biopharma has reported positive topline Phase 3 results for HD204, its proposed biosimilar to Avastin (bevacizumab), marking a potentially important step toward filing in major oncology markets. According to the company, the SAMSON-II study met its primary endpoint in adults with advanced non-squamous non-small cell lung cancer, with clinical equivalence shown on overall response rate at week 18. (prnewswire.com)

The result builds on a long-running development program for HD204. ClinicalTrials.gov identifies SAMSON-II as trial NCT03390686, a head-to-head study comparing HD204 with EU-sourced Avastin in advanced non-squamous NSCLC. Prestige had previously signaled that Phase 3 analysis was underway and that it intended to move into marketing authorization steps after the dataset was completed. The asset has also been part of a broader commercialization strategy: in 2022, Prestige and Intas announced a partnership covering the US, Europe, Canada, parts of Latin America, MENA, South Africa, CIS, and several Southeast Asian markets. (clinicaltrials.gov)

In the company’s March 24, 2026 announcement, SAMSON-II was described as a randomized, double-blind, parallel-group, multicenter Phase 3 trial enrolling 625 patients across 91 centers in 15 countries. Patients were randomized 1:1 to HD204 or Avastin alongside standard chemotherapy. Prestige reported a week-18 overall response rate of 48.7% for HD204 and 46.5% for Avastin, with both the risk ratio and risk difference falling inside the predefined equivalence margins. The company also said safety, pharmacokinetic, and immunogenicity findings were comparable between arms. (prnewswire.com)

While no independent expert reaction was readily available in the immediate aftermath of the announcement, the broader market context is clear: bevacizumab is no longer an early-entry biosimilar category. The FDA’s biosimilar database shows five approved Avastin biosimilars in the US as of April 1, 2026: Mvasi, Zirabev, Alymsys, Vegzelma, and Avzivi. That means HD204, if approved, would enter a market where reference-product displacement is already well underway. (fda.gov)

That commercial backdrop matters because oncology biosimilars have been among the fastest-adopting biosimilar segments, but they are also part of a wider wave of biosimilar activity across high-value biologics. Recent examples include Teva’s FDA approval for Ponlimsi, a biosimilar to Prolia (denosumab), for all indications of the reference product, and FDA and EMA acceptance of Teva’s omalizumab biosimilar for review across all approved Xolair indications. In both cases, the company said the submissions were supported by analytical and clinical data showing similar efficacy, safety, and immunogenicity to the originators. Against that backdrop, a positive Phase 3 readout for HD204 fits a broader pattern: developers are still investing heavily in late-stage biosimilars even in categories where competition is already established.

A 2025 market review citing Samsung Bioepis data reported that oncology biosimilars reached an average 81% market share within five years of launch, and bevacizumab biosimilars specifically had reached about 90% market share by late 2024. The same review said Q1 2025 average sales price discounts in the bevacizumab biosimilar segment were about 49%, reflecting the pricing pressure new entrants face. (ajmc.com)

Why it matters: For veterinary professionals, this is less about direct clinical use and more about the direction of biologics development, manufacturing, and pricing. Human oncology biosimilars remain a leading indicator for how complex biologics markets mature, and the same is increasingly true across other biologic classes such as denosumab and omalizumab: once multiple products are approved or under review, uptake can be rapid, reimbursement policy can reinforce adoption, and price compression can become significant. Those same dynamics influence investment, manufacturing capacity, regulatory expectations, and, over time, the feasibility of advanced biologics in animal health. CMS reimbursement policy has also helped support biosimilar uptake in the US by paying qualifying biosimilars at ASP plus 8% of the originator’s ASP through 2027, which has strengthened the economics for providers. (ajmc.com)

For Prestige specifically, positive SAMSON-II data appear to remove a major clinical hurdle, but they don’t guarantee commercial success. Inference: the bigger challenge now may be differentiation, not proof of biosimilarity, because HD204 would be arriving after several established competitors have already shaped formularies, contracting, and prescribing patterns. That said, additional entrants can still matter if they improve supply resilience or deepen price competition. (prnewswire.com)

What to watch: The next key signals are full data presentation, regulatory filing timing in the US and Europe, and whether Prestige or its partners outline a launch strategy that can stand out in an already mature bevacizumab biosimilar market. Recent FDA approvals and filing acceptances in other biosimilar categories also reinforce that the regulatory pipeline remains active well beyond oncology. (prnewswire.com)