Mosaic Therapeutics Strengthens Leadership with Appointment of Dr. Allison Jeynes as Board Chair to Drive Clinical Growth
Mosaic Therapeutics, a biotechnology company focused on developing innovative targeted combination therapies for hematological and solid cancers, has announced the appointment of Dr. Allison Jeynes as Chair of its Board of Directors. The leadership transition marks an important milestone as the company prepares to advance its oncology pipeline into clinical development and strengthen its position as an emerging clinical-stage biotechnology company.
Dr. Jeynes succeeds Dr. Edward Hodgkin, who has served as Chair and played a significant role in guiding Mosaic through its early stages of growth. While stepping down from the Chair position, Dr. Hodgkin will continue to contribute to the company’s strategic direction as a Non-Executive Director, ensuring continuity during this critical phase of development.
The appointment reflects Mosaic Therapeutics’ commitment to reinforcing its leadership team with experienced executives capable of navigating the complexities of clinical development, regulatory engagement, financing, and commercialization. As the company accelerates the development of its lead oncology programs, Dr. Jeynes’ extensive background in global drug development is expected to provide valuable strategic oversight.
A Veteran Leader in Drug Development
Dr. Allison Jeynes brings more than 30 years of experience across clinical medicine, pharmaceutical research, biotechnology leadership, and corporate strategy. A UK-trained medical oncologist, she has established a distinguished career overseeing the development of innovative therapies across multiple therapeutic areas, including oncology, immunology, and respiratory diseases.
For the past 13 years, Dr. Jeynes has served as Chief Executive Officer of Avillion, a clinical development company that partners with pharmaceutical and biotechnology organizations to accelerate the advancement of promising medicines. Under her leadership, Avillion successfully managed multiple late-stage development programs, achieving an exceptional record of progressing Phase III clinical trials through regulatory review and ultimately securing approvals from the U.S. Food and Drug Administration (FDA).
Her leadership has also extended to fundraising and corporate growth. As founder and CEO, she helped secure approximately $400 million in financing, demonstrating her ability to attract investment while guiding organizations through key development milestones.
Throughout her career, Dr. Jeynes has contributed to approximately 20 successful drug approvals worldwide. Her extensive experience includes direct engagement with major global regulatory agencies, including the FDA, the UK’s Medicines and Healthcare products Regulatory Agency (MHRA), and the European Medicines Agency (EMA). This breadth of regulatory expertise positions her well to help Mosaic navigate future clinical and regulatory pathways.
Prior to leading Avillion, Dr. Jeynes held senior leadership positions at several major pharmaceutical companies, including Wyeth, Bristol Myers Squibb, and Novartis, where she gained extensive experience in clinical development, portfolio strategy, and product commercialization.
Her medical career began at the renowned Royal Marsden Hospital in the United Kingdom, where she practiced as a medical oncologist after earning her MB ChB medical degree from the University of Sheffield.
Supporting Mosaic’s Transition to a Clinical-Stage Company
Mosaic Therapeutics has reached an important stage in its evolution. Since its establishment, the company has focused on identifying novel targeted drug combinations capable of addressing cancers that remain difficult to treat using existing therapies.
As its lead programs move toward human clinical trials, the company recognized the need for leadership with substantial experience in late-stage development and commercialization. Dr. Jeynes’ appointment is intended to strengthen governance while helping guide strategic decisions related to clinical execution, financing, partnerships, and long-term growth.
Chief Executive Officer Thomas Fuchs welcomed the appointment, emphasizing the importance of adding proven clinical development expertise to the company’s Board.
According to Fuchs, Dr. Jeynes has consistently demonstrated the ability to lead complex drug development programs while successfully raising capital and navigating global regulatory processes. He noted that her experience significantly enhances the Board’s strategic capabilities as Mosaic advances toward becoming a clinical-stage biotechnology company.
Leadership Transition Ensures Continuity
The Board transition also recognizes the significant contributions of Dr. Edward Hodgkin, who has helped oversee Mosaic’s growth since its early development.
As Managing Partner at Syncona Investment Management Limited, Dr. Hodgkin played an instrumental role in supporting Mosaic’s scientific strategy, organizational development, and governance. He also worked closely with fellow Board members and executive leadership throughout the succession planning process that ultimately resulted in Dr. Jeynes’ appointment.
Rather than leaving the organization, Dr. Hodgkin will remain actively involved as a Non-Executive Director. His continued presence provides valuable institutional knowledge and strategic continuity while supporting the new Chair during the company’s next phase of expansion.
Maintaining experienced leadership alongside new perspectives is expected to strengthen Mosaic’s governance as it prepares to initiate clinical studies.
A Promising Oncology Pipeline
At the center of Mosaic Therapeutics’ research strategy is the development of targeted combination therapies designed to improve outcomes for patients with difficult-to-treat cancers.
Unlike traditional approaches that often rely on single therapeutic agents, Mosaic seeks to identify rational drug combinations capable of overcoming treatment resistance while improving efficacy.
The company’s lead development program is ASTX295, a highly potent MDM2 antagonist designed to spare bone marrow toxicity—a challenge associated with many existing therapies targeting the same pathway.
MDM2 inhibitors have attracted considerable attention in oncology because they reactivate the tumor suppressor protein p53, which plays a central role in controlling abnormal cell growth. Many cancers retain functional p53 but evade its protective effects through excessive MDM2 activity. Blocking MDM2 may therefore restore the body’s natural ability to suppress tumor progression.
ASTX295 has been specifically designed to minimize bone marrow toxicity while maintaining strong anti-cancer activity, potentially allowing it to be combined with additional targeted therapies across both hematological malignancies and solid tumors.
This combination-focused strategy aligns closely with Mosaic’s broader mission of developing innovative treatments for cancers where existing targeted therapeutic options remain limited.
Origins in World-Class Cancer Research
Mosaic Therapeutics traces its scientific roots to pioneering cancer research conducted at the Wellcome Sanger Institute in collaboration with the Netherlands Cancer Institute.
Researchers at these internationally recognized institutions developed innovative approaches for identifying genetic interactions that could reveal highly effective drug combinations against cancer.
Rather than relying solely on conventional drug discovery methods, Mosaic applies advanced biological insights to uncover therapeutic combinations capable of exploiting vulnerabilities unique to specific cancer types.
This scientific platform enables the company to build a diversified oncology pipeline addressing multiple malignancies while focusing on patients with significant unmet medical needs.
The company’s portfolio now includes several active oncology programs that extend beyond its lead MDM2 inhibitor, providing opportunities for future pipeline expansion.
Strategic Licensing Accelerates Development
A major milestone in Mosaic’s development occurred in April 2025 when the company licensed ASTX295 from Astex Pharmaceuticals.
The licensing agreement significantly strengthened Mosaic’s pipeline by adding a clinical-stage oncology asset with considerable therapeutic potential.
The acquisition complements Mosaic’s internally developed discovery capabilities while accelerating its transition toward clinical development.
By combining proprietary scientific research with strategically licensed assets, Mosaic aims to build a sustainable oncology pipeline capable of generating multiple targeted combination therapies.
Preparing for First Clinical Combination Trial
Looking ahead, Mosaic Therapeutics plans to initiate its first clinical combination study involving ASTX295 during mid-2027.
This anticipated milestone will represent the company’s transition from preclinical innovation into human clinical evaluation.
Preparation for this study includes manufacturing readiness, regulatory planning, clinical site selection, and continued optimization of combination strategies designed to maximize therapeutic benefit.
Dr. Jeynes’ extensive experience overseeing Phase III clinical programs and regulatory approvals is expected to play a valuable role in guiding these preparations while helping position the company for future clinical success.
Expanding Global Leadership
Beyond her responsibilities at Mosaic Therapeutics, Dr. Jeynes maintains an active presence across the biotechnology and life sciences sectors.
She currently serves on the boards of Anaveon and Uniquity Bio, while also acting as Chair of Siolta Therapeutics. Additionally, she provides strategic guidance through senior advisory roles with Blackstone Life Sciences and Recordati.
These appointments reflect her broad expertise across biotechnology investment, corporate strategy, and therapeutic innovation.
Her experience working with emerging biotechnology companies as well as established pharmaceutical organizations provides Mosaic with access to insights spanning scientific development, business strategy, financing, and commercialization.
The appointment of Dr. Allison Jeynes represents a significant step forward for Mosaic Therapeutics as the company enters one of the most important phases of its evolution. With an experienced leader at the helm of its Board, Mosaic is well positioned to advance its oncology pipeline toward clinical development while strengthening its long-term growth strategy.
Supported by a foundation of cutting-edge cancer research, a promising clinical-stage lead asset in ASTX295, and a pipeline centered on innovative targeted combination therapies, the company aims to address cancers with substantial unmet medical needs. As preparations continue for its first combination clinical study in 2027, Mosaic Therapeutics is positioning itself to become an important contributor to the future of precision oncology and combination cancer therapeutics.