Plantibodies

Drugs based on antibodies have been in use for a long time now. So far, almost all these antibody-based drugs have been derived from animal sources -- usually mammalian cells from hamsters -- and then grown in large stainless steel vats. US-FDA has approved around 30 such drugs, including blockbuster cancer therapies such as Avastin and Rituxan (Roche).

The ongoing Ebola epidemic has brought into focus antibodies derived from plants (aka Plantibodies!). In the absence of any credible therapies, Mapp Pharmaceuticals (San Diego, USA) has been permitted to produce experimental 'Plantibodies' to treat two infected medical workers. Despite lower costs of plant-based production (~1/10th!) not many companies are into this area. The only such FDA approved drug is Elelyso, an enzyme produced from genetically engineered carrots, manufactured by Israel's Protalix Biotherapies, and marketed by Pfizer.

Which are the ~30 animal-derived drugs currently in the market? Why is it that major pharma companies are shying away from plant-based production lines that is supposed to be cheaper?

..........................................................................................................
REFERENCES /LINKS

* Plantibodies (Reuters, 18Aug14) --  http://www.reuters.com/article/2014/08/17/us-health-ebola-plants-analysis-idUSKBN0GH0DU20140817

* Ebola puts focus on drugs made in Tobacco plants -- http://www.jamaicaobserver.com/latestnews/Ebola-puts-focus-on-drugs-made-in-tobacco-plants