Malaria is a
Bill Gates on the Goal of 300m Malaria Cures
© 2013 Amyris
mosquito-borne infectious disease by parasitic single-celled
The most effective treatment for malaria infection is the use of artemisinins
, which is mostly extracted from plants. China and Vietnam provide 70% and East Africa 20% of the raw plant material. Seedlings are grown in nurseries and then transplanted into fields. It takes about 8 months for them to reach full size. The plants are harvested, the leaves are dried and sent to facilities where the artemisinin is extracted using solvent, typically hexane. The market price for artemisinin has fluctuated widely, between $120 and $1200 per kilogram from 2005 to 2008.
Now there is a modified, biosynthetic process for artemisinic acid, initially designed by Jay Keasling at the University of California, Berkeley and optimized by Amyris. They had engineered yeast to produce small amount of the precursor artemisinic acid. The synthesized artemisinic acid can then be transported out, purified and chemically converted into artemisinin that they claim will cost roughly $0.25 per dose.The research started in 2004 and in April 2013, Sanofi announced the launch of a production facility in Italy to manufacture the drug on a large scale. The partnership to create a new pharmaceutical manufacturing process was led by PATH’s Drug Development program (through an affiliation with OneWorld Health), with funding from the Bill & Melinda Gates Foundation. Sanofi expects to produce 25 tons of artemisinin in 2013, ramping up the production to 55–60 tons in 2014, supplying approximately 1/3 of the global annual need for artemisinin. The price per kg will be $350–400, roughly the same as the botanical source.
The chemical background explained
The green pathway was added to the general yeast pathway
is a compound naturally found in the Chinese Sweet Wormwood plant effective in the treatment of malaria. Its production is hampered by difficult climate and agricultural conditions. The green pathway on the right was added to the DNA of baker's yeast in order to produce artemisinic acid, which can easily be turned into Artemisinin.