• Viva-Thera makes its public debut with four modalities pursuing HIV prevention, treatment and cure, supported by XtalPi's platform capabilities.
• Viva-Thera combines its first atomic-resolution MPER-TMD-CT structure with XtalPi's AI and automation platform to advance a small-molecule PCC.
• MPER vaccine immunogens elicit antibody levels approximately five times those of the study comparator in rhesus macaques; antisera retain antiviral activity at a 1:1,000 dilution.

BOSTON and SHENZHEN, China, Sept. 23, 2026 /PRNewswire/ -- XtalPi (HKEX: 2228) announced that Viva-Thera, a biotechnology company it incubated and backs as a strategic shareholder, has nominated a preclinical candidate (PCC) targeting the membrane-proximal external region (MPER) of HIV-1 gp41. The partners completed discovery and optimization in seven months by combining Viva-Thera's atomic-resolution structural research with XtalPi's AI drug design and automation platform.

In its public debut, Viva-Thera also reported functional vaccine results in rhesus macaques and progress in targeted gene delivery. The company is pursuing HIV prevention and cure through four modalities—vaccines, long-acting small molecules, gene therapy and cell therapy—with XtalPi providing computational design, predictive modeling and experimental automation across the portfolio.

MPER forms part of the membrane-fusion machinery that HIV uses to enter cells. Together with the adjacent transmembrane domain, it retains approximately 90% sequence identity across viral strains, making it an attractive target for broad-spectrum intervention. Its position against the viral membrane and changing conformation have made precise targeting a persistent challenge.

Building on founder and Chief Scientific Officer Dr. Qingshan Fu's extensive MPER research, Viva-Thera's team obtained the first atomic-resolution structure of the HIV-1 Env MPER–transmembrane domain–cytoplasmic tail (MPER-TMD-CT) region using solution nuclear magnetic resonance (NMR). The team then reconstituted MPER-TMD in membrane structures on nanoparticle surfaces, grounding screening in both the target's structure and its membrane environment.

Deploying generative AI from the outset, XtalPi navigated a chemical space of approximately 10 million compounds to quickly isolate five validated hits with desirable drug properties and strong antiviral activity. By continuously leveraging its generative models to engineer and optimize the leads, the partners drove the program to preclinical candidate (PCC) nomination in just seven months.

The AI-accelerated asset targets gp41-mediated membrane fusion at MPER, opening a path toward a broad-spectrum antiviral with a binding site distinct from those addressed by reverse-transcriptase, integrase, and protease inhibitors. Ultimately, the differentiated approach could broaden the range of effective HIV drug combinations and help restore treatment options for patients facing resistance to existing therapies.

The company's vaccine program draws on the same structural foundation. Its MPER immunogens elicited antibody levels in rhesus macaques approximately five times those of the conventional HIV immunogen comparator. Antisera retained substantial inhibition of HIV pseudovirus infection at a 1:1,000 dilution—functional evidence that the immune response could interfere with viral entry.

Viva-Thera's gene-therapy program addresses integrated HIV proviral DNA, which can persist despite antiviral treatment and cause rebound after treatment stops. The company is developing a non-replicating, HIV-derived vector to deliver CRISPR-Cas9 tools to CD4+ T cells. It has completed vector construction, cell-infection experiments and CD4+ T-cell introduction in humanized mice, and is preparing live-virus infection and treatment studies.

Drawing on its extensive track record in drug discovery, XtalPi equips Viva-Thera with an AI and automation platform that scales across multiple therapeutic modalities. Within this collaboration, XtalPi's AI engine actively drives small-molecule generative design, analyzes immunogen conformations and binding affinities, models gene-therapy dosing, and computationally optimizes in vivo immunotherapies. This computational heavy lifting is seamlessly integrated with XtalPi's robotic automation, enabling high-throughput testing and rapid, iterative refinement.

Viva-Thera drives the overarching biological strategy, deploying its structural insights, virological expertise, and targeted delivery systems to direct experimental validation and define the core clinical challenges. Empowered by these integrated capabilities, Viva-Thera is uniquely positioned to advance complementary vaccine, gene, and cell therapies in parallel—simultaneously pursuing broad-spectrum protection against infection and strategies to eradicate the viral reservoir.

"Our vision is to bring together the interventions needed to prevent HIV and ultimately cure it—from blocking infection to addressing the viral reservoir," said Dr. Qingshan Fu, Founder and Chief Scientific Officer of Viva-Thera. "XtalPi's AI and automation platform allows us to pursue that ambition across multiple therapeutic modalities, at a pace and breadth that would be difficult to achieve through conventional R&D. By combining our understanding of HIV biology with these capabilities, we can explore more possibilities in parallel and move promising discoveries toward medicines faster."

"AI's value in science must ultimately be measured by what it makes possible for people," said Dr. Shuhao Wen, Chairman of XtalPi. "Through investment, incubation and partnership, we are committed to giving exceptional scientists the capabilities to tackle difficult diseases where progress could change patients' lives. Viva-Thera embodies that ambition: deep scientific expertise directed at a challenge that has resisted decades of research. Our role is to help teams like this translate their discoveries into medicines that expand treatment options and bring lasting improvements in health within reach."

About Viva-Thera

Viva-Thera Biotech Co., Ltd. is an innovative biopharmaceutical company incubated by XtalPi Inc. Established in 2025, the company has developed a proprietary targeted immunotherapy platform to advance novel therapeutic and preventive approaches for HIV. Its pipeline includes HIV gp41-MPER nanoparticle vaccines, MPER-targeted long-acting therapeutics, targeted delivery systems for CD4+ immune cells, as well as gene therapy and in situ immunotherapy approaches. Viva-Thera is committed to advancing transformative solutions for HIV, with the ultimate goal of achieving breakthroughs in vaccine development and enabling a functional cure for the disease.

About XtalPi

XtalPi Holdings Limited (XtalPi, 2228.HK) 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, high-performance 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.