Two concepts associated with economics, historical materialism and alienated labor, may have been new with Marx.
Jonathan Wolff describes historical materialism as follows:
Historical materialism — Marx’s theory of history — is centered around the idea that forms of society rise and fall as they further and then impede the development of human productive power. Marx sees the historical process as proceeding through a necessary series of modes of production, characterized by class struggle, culminating in communism.
Wolff describes alienated labor as follows:
Here Marx famously depicts the worker under capitalism as suffering from four types of alienated labour. First, from the product, which as soon as it is created is taken away from its producer. Second, in productive activity (work) which is experienced as a torment. Third, from species-being, for humans produce blindly and not in accordance with their truly human powers. Finally, from other human beings, where the relation of exchange replaces the satisfaction of mutual need.
Wolff, Jonathan, "Karl Marx", The Stanford Encyclopedia of Philosophy (Winter 2017 Edition), Edward N. Zalta (ed.), URL = https://plato.stanford.edu/archives/win2017/entries/marx/.