AmerStem Announces Development of Sustainable Vaccine Component QS-21

Success Reflects Ability to Mass Produce QS-21 While Preventing Deforestation

CAMARILLO, Calif.--(BUSINESS WIRE)--#AmerStem--AmerStem, a biotechnology company dedicated to mastering the potential of plants and plant cultures for the production of high-value phytochemicals, announces that it has developed a platform technology that allows the establishment and maintenance of large-scale, sustainable plant cultures. These cultures are designed to continuously produce bioactive compounds (secondary metabolites) or recombinant proteins using a unique modular bioreactor system.

“AmerStem is currently focused on mass production of QS-21, a unique saponin molecule normally created by the Quillaja saponaria tree,” said Rocio Sierra-Honigmann, MD, PhD, who serves as president and CEO of AmerStem. “This tree is found mainly in Chile. QS-21 is one of the most sought-after saponins with strategic importance to the vaccine industry because of its potent immune-enhancing adjuvant properties.”

AmerStem has already established a number of Quillaja plant cell and root founder cultures in various configurations designed to propagate with the maximum biomass yield and to generate liquid culture media containing the high-value saponins of interest, including the potent immunoadjuvant QS-21. AmerStem has also developed an optimal process to harvest these saponins and isolate homogeneous preparations of QS-21. AmerStem is poised to scale up this process for mass production.

The emergence of the current COVID-19 pandemic has greatly contributed to an unprecedented surge in QS-21 demand. For this reason, it has led to a growing Quillaja tree deforestation in its natural Chile habitat, with the additional threat of depletion. This problem is compounded by the devastating drought that is currently affecting the natural forests where Quillaja trees grow. Therefore, the emergence of alternative sustainable sources for QS-21 is critically urgent. It also represents a unique business opportunity that AmerStem intends to take advantage of, while helping relieve the ecological damage resulting from deforestation of Quillaja trees.

“With our technology platform, AmerStem is creating a sustainable, environmentally friendly and cost-effective solution for producing a high-demand key ingredient used in vaccine manufacturing, with an extremely high current market value ($100,000-$200,000 per gram),” Dr. Sierra-Honigmann said. She added that realizing this unmet need, other groups are also working on devising alternative and sustainable sources for QS-21 and related saponins. “However, their approach relies either on low-yield standard micro-propagation methods or chemical semisynthesis (or partial chemical synthesis). Instead, AmerStem’s sustainable platform is based on authentic Quillaja plant cultures to continuously produce QS-21 (and other saponins) and simplify the process to harvest and separate QS-21 from other components in a minimum number of steps,” she said.

The central market strategy adopted by AmerStem relies on establishing collaborative and/or purchase agreements with major vaccine manufacturers. For example, a major pharmaceutical company, the number one consumer of Quillaja saponins in the world, is actively seeking viable sources of QS-21. Other leading vaccine makers will require a source of QS-21 and related saponin adjuvants before they can manufacture and roll out a protein-based vaccine platform.

The AmerStem core management team consists of the co-founders, two seasoned scientific experts and managers with advanced doctoral and post-doctoral training in premier academic institutions, including Johns Hopkins and Yale University. Dr. Rocio Sierra-Honigmann, co-founder of AmerStem, is a cell culture biologist and cellular immunologist with in-depth expertise in plant cell and root cultures. Dr. Jaime Flores-Riveros, CSO, has more than 25 years of experience in R&D and pharmaceuticals with expertise in biochemistry, analytical chemistry, molecular biology and plant metabolomics.

For more information, visit www.amerstem.com.

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Susan Tellem, RN, BSN; susan@tellemgrodypr.com; 310-313-3444 (o) 310-613-3504 (c)