ViVac Pharma Ltd., a pioneering synthetic biology company developing RNA-lipid nanoparticle (LNP) immunotherapies, announced the appointment of Keren Leshem as Chief Executive Officer on November 20, 2025. The leadership change positions the Jerusalem-based biotechnology company to accelerate its preclinical oncology pipeline targeting treatment-resistant solid tumors.
Leshem brings nearly three decades of experience leading clinical-stage life science companies and translating breakthrough research into commercial success. Recognized by Forbes and Entrepreneur as one of the most influential leaders, she previously served as a World Economic Forum Technology Pioneer CEO.
Revolutionary RNA-Based Cancer Immunotherapy Platform
ViVac's technology platform traces its origins to the reengineering of viruses—one of nature's most powerful immune activators—into safe, self-limiting RNA blueprints. The company's approach applies viral logic to oncology, creating programmable cancer immunotherapies that combine viral potency with RNA-level safety.
"ViVac's science represents a paradigm shift in oncology—using synthetic RNA to mimic the potency of viral immunity, but with the control and safety of modern nanomedicine," said Keren Leshem, Chief Executive Officer. "It's an honor to lead a team of world-class scientists and investors as we build the next generation of RNA-based cancer immunotherapies."
The platform reprograms RNA to behave like a virus, activating localized immune responses without viral replication. This modular RNA-LNP system is designed for scalability across multiple tumor types, offering potential for rapid expansion beyond initial indications into a wide range of cancers.
Preclinical Pipeline Targets Treatment-Resistant Cancers
Under Leshem's leadership, ViVac will accelerate its preclinical oncology pipeline, which includes programs targeting liver, ovarian and other solid tumors. These indications represent significant unmet medical needs in tumors resistant to conventional treatments.
The company's core leadership team includes distinguished scientists with pioneering contributions to synthetic biology and nanomedicine. Dr. Lior Nissim, Head of the Biomedical Synthetic Biology Lab, pioneered the first synthetic gene circuit for precise targeting of cancer cells. Prof. Chezy Barenholz, a long-time leader in liposome technology and nanomedicine, co-invented Doxil—the world's first FDA-approved liposomal nanodrug—and ranks among the world's most cited scientists in 2024, placing in the top 0.035% globally. Dr. Ron Lahav serves as Chief Technology Officer and brings expertise in RNA delivery systems.
Market Opportunity and Scientific Vision
The global cancer immunotherapy market is projected to exceed $125 billion by 2032, with significant growth driven by next-generation RNA-based approaches. ViVac's positioning in this expanding market reflects the potential of its synthetic biology platform to address multiple cancer types.
"Keren's leadership, coupled with this exceptional team of pioneers, positions ViVac at the forefront of RNA and nanomedicine innovation," said Prof. Barenholz. "We're building on decades of research to develop novel therapies that can truly outsmart cancer."
Dr. Lior Nissim expressed an ambitious vision for the company's impact: "There will come a time when future generations look back in disbelief that cancer was once a leading cause of death. Our work brings that future closer—where synthetic biology, RNA innovation and highly effective RNA delivery systems turn cancer into a curable condition."
Company Foundation and Investment
ViVac emerged from two world-leading laboratories at the Hebrew University of Jerusalem, combining expertise in synthetic biology and lipid nanoparticle engineering. The company is backed by renowned life science investors, including Dr. Jean de Gunzburg and Tuomas Tenkanen, who bring extensive experience in biotech innovation, mergers and acquisitions, and global commercialization.
