[Shareholder Letter] Letter to Shareholders on the Publication of the 11th Annual Business Report

Dear Valued Shareholders,

On the occasion of the publication of the 11th Fiscal Year FY2026 (July 1, 2025 – June 30, 2026) Annual Business Report, we would like to share with you our business performance over the past year, the current operating environment, and the direction of growth that Prestige Biopharma will pursue going forward.

FY2026 marked an important inflection point — one in which the commercialization of our biosimilar business, long in preparation, began to translate into actual revenue, while we simultaneously laid the groundwork for the next stage of advancement in our innovative drug pipeline.

It remains difficult to fully convey the scale of the Company's transformation through near-term profit and loss figures alone. However, as tangible progress has begun to emerge across both global commercialization and drug development, management will focus its efforts on translating these developments into meaningful corporate value as swiftly as possible.

1. FY2026 Business Performance: The Beginning of Full-Scale Global Commercialization

Over the past year, we concentrated our efforts on the global commercialization and market expansion of our biosimilars, as well as the development of innovative new drugs. As a result, consolidated revenue for FY2026 reached KRW 27.67 billion, representing a significant increase of 81.99% compared to KRW 14.33 billion in the prior year.

① Generating Tangible Commercialization Revenue through Tuznue®

Following its European marketing authorization, Tuznue® (HD201) entered the European market in earnest together with our global partner Teva, generating cumulative revenue of approximately USD 9.8 million from licensing milestone payments, product sales, and royalty income. This achievement is significant not merely as a regulatory approval, but as a demonstration that our internally developed biosimilar is capable of delivering real commercial outcomes on the global stage. Going forward, we will work to expand the geographic reach of sales and supply volumes within Europe, establishing Tuznue as a stable and growing revenue base.

② The Context of Operating Losses and Investment for Future Growth

Consolidated operating loss for FY2026 was KRW 91.99 billion, reflecting the continued investment required to build the foundations for future business growth — including global clinical trials, marketing authorizations, new pipeline research and development, and the establishment of commercial manufacturing infrastructure. In addition, the net loss for the period of KRW 114.50 billion includes a substantial amount of non-cash accounting items not directly linked to actual cash outflows, such as foreign currency valuation losses arising from the rise in the USD/KRW exchange rate (from KRW 1,356.40 to KRW 1,541.50) under the USD-denominated accounting basis we apply. Management is rigorously reviewing the current scale of investment and business priorities, and will work to improve the profitability structure on a step-by-step basis by enhancing cost efficiency alongside the expansion of commercialization revenues.

③ Maintaining a Sound Financial Structure

Following the external audit for FY2026, both the consolidated and separate financial statements received an unqualified audit opinion from our external auditor, Samduk Accounting Corporation. On a consolidated basis, total equity stood at approximately KRW 513.2 billion, with a debt-to-equity ratio of 45.26% — an improvement of 1.44 percentage points compared to the prior year — and equity attributable to owners of the parent increased by approximately KRW 41.1 billion year-on-year to KRW 465.0 billion. We will continue to manage both financial soundness and capital efficiency to ensure that our research, development, and commercialization activities can proceed on a stable footing.

2. Management's Acknowledgment of Market Concerns

Management is acutely aware that the business progress the Company has been making is not yet fully reflected in our market valuation to the extent the market had anticipated. We also recognize that the extended period of research and development investment and operating losses has been a source of concern for shareholders and the market alike.

However, from FY2026 onwards, a clear shift has begun in the Company's business structure. Our biosimilars have moved beyond the research, development, and approval stages into the phase of active sales and revenue generation, and our innovative drugs are also advancing to the next stage with a more defined development strategy and path to commercialization.

① Expanding Revenue in the European Biosimilar Market

The European biosimilar market operates primarily through public tenders and country-specific supply contracts, meaning that a certain period is required after product approval before revenues begin to materialize in earnest. Tuznue is currently progressing through this market entry process in a phased manner. We intend to build upon our established commercialization foothold in Europe and extend it to Latin America (LATAM), the Middle East and North Africa (MENA), and other regions, with the goal of constructing a globally diversified revenue structure that is not dependent on any single region.

② Continued Investment in Technology for Future Growth

The development of innovative new drugs requires more time, capital, and a higher level of scientific validation than biosimilars. Our flagship innovative drug, PBP1510, has been developed with deliberate care to fully characterize its safety profile, early efficacy signals, and appropriate patient population. Building on this development experience, we intend to sharpen our focus and prioritize research and development efforts more rigorously — clarifying the priorities for clinical development, concentrating resources on our core pipeline, and actively leveraging global partnerships and licensing opportunities to enhance development efficiency and commercial potential.

In parallel, through our research and development investments, we have continued to accumulate proprietary technologies and intellectual property that will serve as the foundation for future growth. Key achievements include the fibrosis indication expansion technology for PBP1710 (filed January 20, 2026 — application of CTHRC1-targeting antibody to fibrosis treatment), the IDC007 bispecific antibody candidate (filed February 24, 2026 — material secured for CRS treatment), the IDC224 SC formulation platform core technology (filed April 21, 2026 — antibody subcutaneous formulation technology), and the IDC221 TASA™ diagnostic platform core technology (filed August 4, 2026 — PAUF-based blood diagnostic technology). We will continue to enhance the commercial potential of these core technologies and their contribution to long-term corporate value.

3. Road Map for Global Revenue Expansion and Innovative Drug PBP1510

The Company's core priorities going forward are to extend the global commercialization success initiated by Tuznue into additional markets, and to substantiate the value of PBP1510 and our other innovative drug candidates through objective clinical data.

① Expanding into LATAM and the Middle East & North Africa (MENA)

We are working with our global partners to continuously expand the geographic reach of Tuznue's commercialization. In August 2026, we secured GMP certification from Brazil's health regulatory authority ANVISA for the manufacturing facility of our affiliate Prestige Biologics, establishing the production foundation required for entry into the Brazilian market. This was followed by marketing authorization in Trinidad and Tobago in September 2026, and subsequently marketing authorization in Brazil for both the 150 mg and 440 mg dosage strengths. In Brazil, our local marketing authorization holder, Dr. Reddy's Laboratories, will be responsible for local marketing, sales, and product supply under an exclusive licensing agreement, and both parties will proceed with the product launch and commercial rollout. Building on these achievements, we will continue to expand product registrations and launches across key LATAM and MENA markets, progressively broadening the geographic reach and revenue base of Tuznue's global commercialization.

② Pancreatic Cancer Drug PBP1510: Value as a Potential Game-Changer and Development Timeline

PBP1510 (Ulenistamab) is our flagship innovative drug candidate, targeting PAUF (Pancreatic Adenocarcinoma Upregulated Factor), a protein associated with pancreatic cancer. PBP1510 is currently preparing to advance into Phase 2a clinical development based on data generated from the Phase 1 study, and we will pursue the expeditious completion of its development through a more clearly defined patient population and clinical strategy. Going forward, we also plan to actively explore the potential utilization of various FDA expedited development pathways, based on clinical outcomes and ongoing dialogue with regulatory authorities.

The pancreatic cancer treatment landscape is evolving rapidly, with new targeted therapeutic strategies — including those directed at RAS and other targets — emerging and reshaping the treatment paradigm. Nonetheless, pancreatic cancer remains a disease with a substantial unmet medical need. We are committed to demonstrating the clinical value of PBP1510 through its differentiated mechanism of action targeting PAUF — distinct from existing therapies — and to securing a meaningful role for the asset within a broad range of treatment strategies, including combination therapy, thereby expanding its commercial potential.

4. Three Strategic Priorities for Enhancing Corporate Value

Management will concentrate its efforts on the following three key priorities:

First, expanding global revenue from Tuznue.

We will extend the commercialization that began in Europe into additional markets, including Latin America and MENA, and convert the ongoing marketing authorization applications and supply contracts across various countries into tangible product revenue.

Second, improving cost efficiency and re-establishing pipeline priorities.

We will enhance the efficiency of manufacturing and R&D expenditure, concentrate resources on our highest-value core pipeline assets, and work to improve our profit and loss structure over the medium to long term while building a sustainable business foundation.

Third, objectively demonstrating the value of our innovative drugs and advancing global commercialization.

We will rapidly advance the follow-on clinical development of PBP1510 on the basis of its clinical data, and substantiate the value of the asset through concrete clinical outcomes. Building on this, we will actively pursue a broad range of commercialization opportunities — including global partnerships and licensing.

FY2026 was a year in which we began generating meaningful revenue in the European market through Tuznue, advanced preparations for the next stage of clinical development for PBP1510, and made meaningful progress on both the biosimilar and innovative drug fronts. Even after the close of the fiscal year, our global commercialization expansion has continued, with marketing authorizations secured for Tuznue in Trinidad and Tobago and Brazil.

We extend our sincere gratitude to our shareholders for your continued trust in the Company's potential and technological capabilities. Prestige Biopharma will remain steadfastly focused on expanding global revenue and enhancing the value of our core pipeline — and we are committed to proving ourselves through numbers and results.

September 28, 2026

Sincerely,

Management of Prestige Biopharma Co., Ltd.