Mosaic Therapeutics Acquires Two Clinical-Stage Oncology Programs from Astex to Develop Novel Combination Therapies
Key Insights
Mosaic Therapeutics (search) has in-licensed two clinical-stage oncology programs from Astex Pharmaceuticals (search), including an ERK1/2 (search) inhibitor and an MDM2 (search) antagonist, both showing promising safety profiles in over 100 patients.
As part of the agreement, Astex has taken a 19% equity stake in Mosaic upfront with an additional 3% tied to clinical milestones, while Astex's CEO Dr. Harren Jhoti will join Mosaic's Board as an observer.
Mosaic's platform identifies synergistic drug pairs for biomarker-defined cancer (search) populations, with the first clinical combination study utilizing these newly acquired assets expected to commence in 2026.
Mosaic Therapeutics (search) Ltd, a targeted oncology company focused on developing novel combination therapies, has secured exclusive rights to two clinical-stage oncology programs from Astex Pharmaceuticals (search), a wholly owned subsidiary of Otsuka Pharmaceutical (search) Co. Ltd. The strategic in-licensing agreement aims to advance Mosaic's mission of delivering precision combination medicines for cancer (search) patients with limited treatment options.
The transaction grants Mosaic exclusive rights to develop proprietary combinations incorporating the licensed compounds, which have already demonstrated promising clinical profiles. In exchange, Astex has acquired a significant equity position in Mosaic, receiving 19% ownership upfront with an additional 3% contingent upon achieving clinical milestones. Astex will also receive potential future revenue shares from successful commercialization.
Acquired Clinical Assets
The two small molecule assets from Astex include:
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ASTX029: An ERK1/2 (search) inhibitor that has completed Phase 2 clinical studies. ERK1/2 is a well-characterized driver in many cancers, particularly those with MAPK pathway (search) alterations.
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ASTX295: An MDM2 (search) antagonist developed in collaboration with the Cancer (search) Research UK Drug Discovery Unit at Newcastle University, which has completed Phase 1 clinical evaluation.
Both compounds have been studied in more than 100 patients each and have demonstrated differentiated safety profiles within their respective target classes. Importantly, they have shown single-agent activity as monotherapies, making them promising candidates for combination approaches.
Synergistic Platform Approach
Mosaic's proprietary platform identifies pairs of oncology drugs predicted to have synergistic activity in biomarker-defined patient populations. This approach aims to achieve greater efficacy and durability of response compared to single-agent treatments.
"Mosaic's mission is to bring novel targeted combination medicines to patients who need them," said Dr. Edward Hodgkin, Managing Partner of Syncopal Investment Management Limited and Chair of Mosaic. "The in-licensing of these two clinical-stage assets provides a step change in our development pipeline, allowing Mosaic to progress targeted drug combinations in novel biomarker-defined settings and enabling the delivery of precision medicines for patients who currently have few therapeutic options."
The company's development strategy for each combination product seeks to establish a broad, biomarker-defined label across multiple tumor types, potentially expanding treatment options for patients across various cancer (search) indications.
Accelerated Development Timeline
The acquisition significantly accelerates Mosaic's development timeline, with the first clinical combination study expected to commence in 2026. This represents a substantial advancement in the company's ability to bring novel treatment options to patients.
Dr. Harren Jhoti, Co-founder, President and CEO of Astex, who will take an observer role on Mosaic's Board, commented: "We recognize the significance of Mosaic's platform, which has identified these two assets as anchor components of a pipeline of potential combination products. Both drug targets are well-characterized drivers of many cancers, and we are excited to be working with the experienced team at Mosaic to expand the Company's pipeline in combination therapies with high unmet medical need."
Addressing Unmet Clinical Needs
The partnership between Mosaic and Astex represents a significant step forward in addressing the complex challenges of cancer (search) treatment. By leveraging Mosaic's platform to identify synergistic drug combinations and Astex's clinically validated assets, the collaboration aims to develop more effective therapies for patients who currently have limited treatment options.
The biomarker-driven approach aligns with the growing trend toward precision medicine in oncology, where treatments are tailored to specific molecular characteristics of a patient's tumor. This strategy has the potential to improve response rates and outcomes while minimizing unnecessary exposure to ineffective therapies.
Financial details beyond the equity stake have not been disclosed, but the partnership consolidates the relationship between these two innovation-driven businesses in their shared mission to advance cancer (search) therapeutics.