The Chinese medicinal herb you're thinking about is sweet wormwood, from which we isolated artemisinin. Artemisinin isn't a suppressed secret. It's one of the major treatments for malaria and it netted its discoverer a Nobel prize.
The drug the article is talking about contains artemisinin in combination with another substance.
We know how to deal with malaria, so this isn't some story of Big Pharma hiding the truth. The disease used to be endemic in the US and in Europe. Better treatments save lives, but eradication hinges on economic and political factors... which are in turn not helped by malaria.