Clinical trials with Staphylococcus aureus and protein A in the treatment of malignant disease

Perfusion of plasma from tumor-bearing animals over Staphylococcus aureus with membrane-bound protein A has resulted in significant tumor shrinkage. Similar therapy has now been given to 16 patients by three methods. No tumor responses have been observed. Five patients were treated with perfusion over fixed and killed S. aureus Cowan I. Cardiovascular and respiratory toxicity was excessive and appeared to be related to volume and rate of plasma infused. Eight patients were treated with perfusion of autologous plasmas over protein A-collodion-charcoal. Doses of plasma ranged from 50 to 450 ml. No toxicity was noted. Three patients have been treated with perfusion over protein A-silica. Toxicity in two resembled that seen in the S. aureus trials, although it was not as severe. We conclude that the toxicity of this therapy can be life-threatening, and human trials should be undertaken with caution.