Figure 2. Tumor stromal depletion of hyaluronan by PEGPH20 in combination with GVAX enhances CD8⁺ T-cell infiltration in PDAC and improves survival compared to single agent therapies.

Following the inoculation of KPC tumor cells by either orthotopic implantation or the hemispleen procedure, mice were treated with Cy (100 mg/kg) on Day 6, PEGPH20 (40μg/kg) on Day 6 and GVAX on Day 7. Flow cytometry was performed on tumor infiltrating lymphocytes (TIL) isolated from processed dissected orthotopic tumor or diffusely metastatic liver respectively. Each experimental group consisted of 3 or 4 mice analyzed individually. Relative percentage and total number of live CD3⁺CD8⁺ TIL in the combination PEPGH20/GVAX treatment group compared to single agent treatment groups in the (A) orthotopic model and (B) hemispleen model respectively. Relative percentage and total number of live CD3⁺CD4⁺ TIL in the combination PEGPH20/GVAX treatment group compared to single agent treatment groups in the (C) orthotopic model and (D) hemispleen model respectively. Data represent mean ± SEM from one representative experiment that was repeated three times. ns not significant, * p<0.05,** p<0.01, ***p<0.001. (E) Kaplan Meier survival curves of mice implanted with PDAC cells in untreated mice (n=22), mice treated with Cy/GVAX alone (n=18), PEGPH20 alone (n=18), or the combination PEGPH20/GVAX treatment (n=18). Data represent the combined data of two consecutive experiments. ns not significant, * p<0.05. (F) Kaplan Meier survival curves of mice implanted with PDAC cells in untreated mice (n=10) or mice treated with the combination PEGPH20/GVAX treatment with CD8⁺ T-cell depletion (n=10) and without CD8⁺ T-cell depletion (n=10). ns not significant,** p<0.01.