HotHouse Therapeutics has emerged from stealth with £2.9 million in pre-seed funding to advance an AI-enabled plant bioengineering platform that aims to transform how modern medicines are discovered and manufactured. The Norwich-based startup secured investment from SynBioVen, Start Codon, UKI2S, Twin Path Ventures, Wren Capital, multiple angel investors, and an Innovate UK grant.
The company is using its newly revealed platform to address one of the vaccine industry’s most persistent supply constraints: global dependence on a single, unsustainable source of the critical adjuvant QS-21.
At present, QS-21 is derived from the bark of a slow-growing Chilean tree, resulting in a fragile and resource-intensive supply chain that cannot meet rising international demand and disproportionately affects low- and middle-income countries.
HotHouse Therapeutics aims to replace this bottleneck with bioengineered plant systems that can be grown efficiently and cost-effectively anywhere. Its platform combines AI-powered design tools with a transient plant expression system that reprograms plant leaves into miniature chemical factories capable of producing both natural and novel molecules in days. The company states that its approach creates a carbon-positive, scalable production pathway suited for global health applications that require predictable supply and improved affordability.
The company’s BotanAI design engine works with its BotanBIO production system to rapidly generate high-purity, single-entity compounds. While its initial focus is on next-generation saponin-based vaccine adjuvants, including sustainable sources of QS-21, QS-7, and a growing library of novel derivatives, HotHouse also plans to expand into traditional drug discovery programs by advancing new assets through clinical development.
The scientific foundation for the platform is based on the work of Professor Anne Osbourn OBE, FRS, Novozymes Prize Laureate 2023, and an international member of the US National Academy of Sciences. Her research has demonstrated that complex molecules such as QS-21 can be fully biosynthesised in plants. HotHouse’s team includes plant biologists, chemists, natural product specialists, purification researchers, and AI engineers.
The company reports that its system can currently unlock over 20 million novel molecules by combining AI-driven pathway prediction with the enzymatic diversity found across the plant kingdom. Its production approach is designed to support vertical farming infrastructure and long-term sustainability metrics, offering an alternative to extractive or resource-intensive chemical manufacturing.
HotHouse will pursue multiple commercial strategies, including exclusive supply of high-value adjuvant chemistry, access to its adjuvant panels for researchers and developers, and bespoke discovery partnerships with pharmaceutical and biotechnology companies. Early preclinical comparisons between the company’s adjuvant candidates and QS-21 are expected to inform upcoming collaborations with global health organisations, vaccine developers, and biopharma firms.
KEY QUOTES
“We grow greener medicines using a platform that makes the impossible accessible. The drug discovery field desperately needs new chemical space and the vaccine field needs new adjuvants, with supply chains that work for everyone. By combining AI with plant engineering, we can reach molecules others cannot, and scale them in a way that supports global health, not just high-income markets.”
“Our mission is simple. Unlock powerful chemistry, make it sustainable, and get it into the hands of the partners who can deliver vaccines and therapeutics to patients across the globe.”
David Sheppard, CEO
