Inhibition of head and neck metastatic and/or recurrent cancer by local administration of multi-cytokine inducer OK-432.

The multi-cytokine inducer OK-432 is a pulverized preparation of the low-virulence SU strain of Streptococcus pyogenes of human origin. A reduction of the tumour mass in the OK-432-injected areas was observed in 11 out of 13 patients with metastatic and/or recurrent head and neck cancer. Complete response (CR), partial response (PR) and minor response (MR) were noted in six, three and two cases respectively. OK-432 local administration therapy could create a new strategy for cancer therapy.