We then evaluated the therapeutic potential of a combined trAb/anti-CTLA-4 treatment in vivo in comparison to monotherapy. Based on previous experiments , the tumor models were adjusted to suboptimal antibody doses to secure detection of any synergisms of the combination approach. Therapy started 2 days after a lethal challenge with B78-D14 melanoma. Treatment with the anti-CTLA-4 mAb HB304 alone had only a marginal effect (Figure 3A), while monotherapy with Surek rescued up to 60% of mice bearing an established B78-D14 burden (Figure 3B). When both antibodies were combined, however, the overall survival of mice increased to 90% (Figure 3B). The data indicate that the approach combining both antibodies has a beneficial effect as compared to Surek monotherapy albeit with a significance of P = 0.08 (logrank).