A lyophilized formulation containing cultures of a low-virulent strain of Streptococcus pyogenes, treated and killed with pencillin G, with potential sclerosing, immunostimulating and antineoplastic activities. Besides its activity as a sclerosing agent, picibanil appears to have multiple effects on the immune system as a non-specific immunostimulant. This agent activates the host immune system by stimulating the activity of natural killer (NK) cells, macrophages and lymphocytes, and by enhancing the production of several key immune mediators, including interleukins (ILs) and tumor necrosis factor (TNF). Check foractive clinical trials using this agent.