XTALPI - VOLUNTARY ANNOUNCEMENT

BUSINESS UPDATE

XtalPi Holdings Limited

晶泰控股有限公司

(Incorporated in the Cayman Islands with limited liability)

(Stock Code: 2228)

VOLUNTARY ANNOUNCEMENT

BUSINESS UPDATE

This announcement is made by XtalPi Holdings Limited (the "Company" or "XtalPi", together with its subsidiaries, the "Group") on a voluntary basis. The purpose of this announcement is to keep the shareholders and potential investors of the Company informed of the latest business development of the Group.

The board (the "Board") of directors of the Company is pleased to announce that it has recently made two breakthroughs in its in-house innovative peptide ingredients and incubated company novel drugs pipeline:

1. One of them is Tensotide, an innovative peptide ingredient independently developed by XtalPi relying on the AI peptide discovery and optimization platform PepiX™, has recently successfully obtained the Self GRAS (generally recognized as safe) certification recognized in U.S. This is the first international safety certification obtained by XtalPi in the field of oral foods after the hair growth efficacy ingredients (Remeanagen™ and AquaKine™) were registered and filed in the U.S., which marks the full chain industrialization capability of the Company's AI peptide platform from "topical use" to "oral administration".

Tensotide is an innovative active peptide independently designed by XtalPi, which has obtained a Chinese invention patent and completed a PCT international patent application. Tensotide targets the energy metabolism pathway as its core mechanism, inhibiting the degradation and absorption of carbohydrates. This peptide maintains high stability under the conditions of strong acids and alkalis and various enzymes, which is significantly better than positive reference substances of the same type. It has four differentiated advantages: high activity, high stability, high safety, and low cost and easy mass production. Through this certification, Tensotide has obtained the core qualification to enter the U.S. food market and dietary supplements in compliance.

Moving forward, XtalPi will continue to expand into fields such as anti-aging cosmetic peptides, lipid-lowering peptides, and uric acid-lowering peptides, to build a dual-track matrix focused on "Beauty and Health."

2. Another is the potential First-in-class/Best-in-class solid tumor targeting pan-TEAD

(TEAD 1-4) inhibitor SIGX2649 independently developed by XtalPi's incubated company Signet Biotech, which obtained the Investigational New Drug (IND) approval of the U.S. Food and Drug Administration (FDA) earlier than expected. This is the second innovative drug pipeline entered into clinical practice by Sigma Biotech, following the entry of the world's first diffuse gastric cancer targeted drug SIGX1094 into phase I clinical trial. XtalPi has the

commercial interest in such pipeline.

SIGX2649 is a pan-TEAD (TEAD 1-4) inhibitor that blocks the Hippo-YAP/TAZ signaling pathway by targeting TEAD, a binding protein of the core transcription factor YAP (an undruggable target) of the Hippo pathway, thereby inhibiting the proliferation, metastasis, and drug resistance of solid tumors. Preclinical research has demonstrated that SIGX2649 exhibits superior anti-proliferative activity in various in vitro tumor models (including liver cancer organoids and mesothelioma), significant in vivo antitumor efficacy, and favorable pharmacokinetic properties, with lower renal on-target toxicity than comparable investigational drugs. Its core preclinical data has been selected for presentation at the American Association for Cancer Research (AACR) Annual Meeting 2026.

About XtalPi

XtalPi was founded in 2015 by three physicists from the Massachusetts Institute of Technology (MIT). It is an innovative R&D platform powered by quantum physics, artificial intelligence, and robotics. By integrating first-principles calculations, AI algorithms, highperformance cloud computing, and standardized automation systems, XtalPi provides digital and intelligent R&D solutions for companies in the pharmaceutical, materials science, agricultural technology, energy, new chemicals, and cosmetics industries.

By Order of the Board

XtalPi Holdings Limited

Dr. Wen Shuhao

Chairman of the Board and Executive Director

Hong Kong, 31 May 2026