The invention relates to a blade of a low-pressure compressor of an axial turbine engine. The blade comprises a vane in which a cavity is formed. The vane has a leading edge and a trailing edge, an intrados surface and an extrados surface which extend from the leading edge to the trailing edge, an outer casing which forms the intrados surface and the extrados surface and which delimits the cavity. The blade further comprises closed foam, such as a polymethacrylic foam, which blocks the cavity in order to isolate it from the environment of the blade. The blade further has a three-dimensional lattice which is formed in the cavity and which is integral with the vane of the blade. This barrier protects from chemical attacks and the introduction of impurities. The invention also relates to a production method for a hollow turbine engine blade which is filled with foam.