"It's one of the most valuable and coveted molecules known, and only nature knows how to produce it. You cannot make this saponin without the plant," says Rocio Honigmann, CEO of AmerStem Inc., a biotech company in Camarillo, California. The company has developed a solution for efficiently producing Quillaja saponaria saponins indoors, including QS-21, a crucial ingredient used in vaccines for diseases such as malaria, shingles, and tuberculosis.
Rocio Honigmann pictured on the right.
Located in Camarillo, the biotech firm is tapping into the potential of a native tree from Chile's Mediterranean forest, a region that's already heavily impacted by global warming. Traditionally, these trees, ranging from 35 to 50 years old, are cut down to extract saponins from their inner bark, as Rocio explains. "Once a tree is harvested, it's gone forever, contributing to deforestation in one of the world's most vulnerable ecosystems."
Reinventing saponin extraction
AmerStem came to fruition when Rocio and her team were forced to revamp their business model during the pandemic after losing an exclusive contract with a crop protection company. They started experimenting with growing vaccines in soybean roots, but while that project was fascinating, it was too small to attract attention. "That's when we decided to turn to a more radical experiment, cultivating native Chilean trees."
"Instead of relying on destructive methods to source saponins, we came up with a modified aeroponic system." In this system, small, bonsai-like trees are grown long-term in nutrient-rich mist chambers where the saponins are produced continuously in the fresh growth, rather than in just the bark. "We listen to the plants," Rocio affirms, "as the whole process hinges on maintaining an intact, living plant."
This method allows for a more sustainable, and year-round harvesting of the saponin without damaging the native trees. "On top of that, this approach bypasses the limitations of traditional extraction methods, which are slow, expensive, and environmentally harmful."
AmerStem's growing facility
A highly wanted molecule
As Rocio explains, saponin QS-21 is in high demand, not only for its critical role as a potent adjuvant in vaccines like GlaxoSmithKline's Shingrix and Arexvy, but also for global vaccines still in development, including those targeting malaria and tuberculosis. The molecule itself is incredibly valuable, around $150,000 per gram, making it one of the most expensive molecules in the world. This value is driven by the molecule's complexity, its low abundance and the unsustainable methods used to source it.
"Saponin QS-21 has a unique structure, including eight sugar residues surrounding a core molecule. This complexity makes them incredibly difficult to replicate in bioreactors, a challenge that has stumped some of the largest pharmaceutical companies," Rocio points out. Yet, Rocio and her team have thus far succeeded 'where others have not', by developing a system that allows them to produce these saponins continuously and at a commercial scale.
The challenges of commercial production
While AmerStem has been able to figure out the science of growing and harvesting these saponins, funding this endeavor for large scale production has been challenging. As Rocio and her team have seen, vaccine development is a time-consuming, complex process that requires clinical trials, careful development, and thorough testing, steps that slow the go-to-market approach. "It's not as simple as selling the saponin tomorrow. Each vaccine has to go through extensive pre-clinical testing and clinical trials, and we're working with pharmaceutical companies to get there."
Expressing her frustration, Rocio explains that the need for these vaccine adjuvants is critical. "Malaria, for example, continues to kill one child in Africa every minute, and tuberculosis claims one life every 15 seconds. Yet, despite the urgent need, large pharmaceutical companies have been slow to invest in the production of vaccines that could target these diseases on a global scale," Rocio says. AmerStem prides itself to have developed a cost-effective and sustainable solution that could change the vaccine adjuvant landscape," says Rocio. However, the biggest barrier is price. Investors see the value, but they hesitate because it's a long-term play."
A simple, but highly efficient system
However, despite these hurdles, Rocio remains optimistic as the in-house developed aeroponic system AeroStemixTM is designed as a scalable and modular platform. The biotech is currently managing trees across 40 tanks, each housing 45 dwarf domesticated trees and is harvesting biomass containing saponins every 30 to 60 days. "Our system is simple but effective. It's not high-tech, but it's low-maintenance, low-cost, and sustainable. We are planning to scale up to a thousand tanks, producing several kilograms of saponin each year," Rocio gives away. Each kilo of dry biomass harvested can yield about 10 grams of the saponin, and with 3,000 plants already in production, AmerStem is on track to produce larger quantities to meet the increasing demand.
Beyond vaccines, Rocio and her team are exploring the potential of secondary products derived from these saponins, including their use as natural insecticides, fungicides, and even in animal feed to improve health outcomes for livestock. "There's no waste in our system," she emphasizes. Everything we grow can be used in some way, whether it's for vaccines, agriculture, or food production."
Licensing technology and search for investment
Looking ahead, the biotech aims to license its technology to grow other types of trees indoors, in particular, Mediterranean fruit trees like lemons, figs, and grapes. "We believe we can change how people think about growing trees indoors. It's not just about small-scale crops like berries or peppers." We already have a small "orchard" of lime and lemon trees indoors as proof of concept. Citrus trees thrive in AeroStemixTM
While the company is still in the initial commercialization phase, AmerStem is actively seeking investors and partners to help them expand its operations. "I'm confident that our IP-protected process will soon gain the traction it deserves. While there's a lot of money to be made, that's not the only goal. We want to make a difference. We want to provide solutions to the world's most pressing health challenges. Furthermore, we are committed to ensuring that the saponins we produce are used to make effective vaccines accessible, particularly in regions where diseases like malaria and tuberculosis continue to devastate populations."
For more information:
AmerStem Inc.
Dr.Rocio Honigmann, CEO
[email protected]
www.amerstem.com