HBM HOLDINGS-B - VOLUNTARY ANNOUNCEMENT - JOINTLY INITIATE MEGASTREAM TECHBIO WITH BIOMAP

和 鉑 醫 藥 控 股 有 限 公 司 HBM Holdings Limited (incorporated in the Cayman Islands with limited liability) (Stock Code: 02142)

VOLUNTARY ANNOUNCEMENT JOINTLY INITIATE MEGASTREAM TECHBIO WITH BIOMAP

This announcement is made by HBM Holdings Limited (the "Company", together with its subsidiaries, the "Group") on a voluntary basis to inform the shareholders and potential investors of the Company about the latest business updates of the Group.

The board of directors of the Company (the "Board") is pleased to announce that the Company and BioMap have entered into a multi-dimensional, long-term global strategic partnership centered on artificial intelligence ("AI")-driven discovery and development of complex biologics (the

"Strategic Partnership"). The Strategic Partnership aims to systematically overcome the critical bottlenecks constraining next-generation innovative therapies and to build a globally competitive, AI-powered R&D ecosystem.

Under the strategic collaboration framework, the Company and BioMap will jointly initiate MegaStream TechBio ("MegaStream"), a next-generation AI-native pipeline company targeting global markets. MegaStream is expected to integrate exclusive datasets, purpose-built large models and a large-scale innovative pipeline portfolio into an AI-powered research and development engine, enabled by an advanced integrated intelligent dry-wet closed loop discovery laboratory, paired with a partner-tailored, multimodal and multi-objective generative large model. MegaStream will focus on addressing critical unmet clinical needs across cardiovascular, renal, oncology and anti-aging disease areas, and will prioritize First-in-Class ("FIC") and Best-in-Class ("BIC") assets as its core development benchmarks.

As the lead founding partner, the Company will grant MegaStream access to its proprietary fully human antibody platform, in-depth target biology know-how and global clinical development capabilities. BioMap, as co-founding partner, will contribute foundational AI technology, model engineering and intelligent research and development capabilities to accelerate pipeline development. MegaStream's initial pipeline is expected to consist of AI-identified drug candidates from the parties' earlier collaborations and newly launched AI-driven discovery programs. The founding parties are expected to be entitled to potential upfront payments, success-based milestone payments and royalty sharing in accordance with industry practice. In addition, MegaStream's core management team is expected to be composed of seasoned executives from multinational biopharmaceutical companies and leading experts in artificial intelligence, with key appointments currently underway.

The Board believes that the Strategic Partnership represents a further advancement of the Group's existing collaboration with BioMap and is expected to strengthen the Group's AI-enabled discovery

engine, expand the application scenarios of the Group's technology platforms and support the Group's strategy of developing differentiated next-generation complex biologics.

About BioMap

BioMap is a global leader in AI foundation models for life sciences, dedicated to building next-generation AI infrastructure to accelerate scientific discovery across the industry.

BioMap's proprietary 268-billion-parameter life sciences foundation model family, xTrimo, learns the underlying rules governing genes, proteins, cells, and biological systems, delivering highly accurate AI-driven predictions. It has achieved state-of-the-art (SOTA) performance across more than 300 predictive tasks spanning over 20 life science subfields, and was awarded the championship title at the first global Virtual Cell Challenge.

Built upon its foundation model, BioMap's product BioMap OS is an AI-powered life sciences discovery system that enables users to establish systematic AI capabilities. Through AI-driven dry-wet closed-loop discovery, it supports data insights, parameter optimization, and de novo design, while empowering users to accumulate proprietary data and train their own AI models, continuously enhancing their AI capabilities over time. BioMap currently supports over 800 institutional users worldwide, spanning multiple verticals including antibody and protein, innovative therapies and precision medicine, synthetic biology, and frontier scientific research.

Cautionary Statement: We cannot guarantee that any drug candidate will be successfully developed or ultimately marketed by the Company and/or its collaboration partners. Shareholders and potential investors of the Company are advised to exercise due care when dealing with the shares of the Company.

Forward Looking Statement

There is no assurance that any forward-looking statements regarding the business development of the Group in this announcement or any of the matters set out herein are attainable, will actually occur or will be realized or are complete or accurate. The financial and other data relating to the Group as disclosed in this announcement has also not been audited or reviewed by its auditors. Shareholders and/or potential investors of the Company are advised to exercise caution when dealing in the shares of the Company and not to place any excessive reliance on the information disclosed herein. Any shareholder or potential investor who is in doubt is advised to seek advice from professional advisors.

By order of the Board

HBM Holdings Limited Dr. Jingsong Wang Chairman and Executive Director

Hong Kong, 15 June 2026