Evaluation of 92.1's proliferative potential was done with RT-CES (A and B). Each experimental condition was repeated eight times. This technology yielded kinetic growth data which showed combination treatment with lenalidomide and sorafenib (1:1) to have an anti-proliferative effect, which is first apparent at 0.001 μM and most profoundly independent from either single agent's effect at 0.01 μM (A). Lenalidomide alone showed no appreciable activity against proliferation regardless of concentration. Sorafenib alone exhibited anti-proliferative activity which was initially evident at 0.1 μM (B), 10–100× more concentrate than when a similar effect is produced by combination therapy. When therapy was evaluated with the xenograft model, the combination treatment cohort showed the most tumor growth delay Each treatment group represents eight animals. (C). Lenalidomide and sorafenib both displayed tumor growth stasis which was significantly different from carrier treated animals and equivocal from each other. Combinatory therapy showed significant growth retardation relative to either monotherapy. This pattern of anti-tumor efficacy was also seen in the analysis of metastatic frequency. Each treatment group represents eight animals (D).