Background <p>We previously reported that mirogabalin, a selective voltage-gated calcium channel α2δ1/α2δ2 ligand, increases the proliferative potential of pancreatic cancer. However, the risk of pregabalin, a non-selective α2δ ligand, is unknown in pancreatic cancer. Therefore, the proliferation of murine pancreatic cancer cell lines was studied following treatment with pregabalin.</p> Methods <p>Six-week-old pancreatic cancer mouse model KPPC (LSL-Kras^G12D/+; Trp53^flox/flox; Pdx-1^cre/+) was orally administrated pregabalin 30 mg · kg⁻¹ · day⁻¹ (<i>n</i> = 10), or vehicle water (<i>n</i> = 14) until the humane endpoint (no activity, food intake of &lt;1 g · day⁻¹ or more than 20% body weight loss within several days). Cancer-related pain was assessed using the scores of the hunching and mouse grimace scale. Tumor status and plasma cytokine levels were determined using histopathological analysis and cytokine antibody arrays, respectively. Proliferative effect of pregabalin was investigated using mouse pancreatic ductal adenocarcinoma cell lines.</p> Results <p>The number of pancreatic cancer cells were increased by 100 and 300 μM pregabalin in vitro. The pain scores in KPPC mice were decreased by pregabalin, but there was no significant difference in the survival rate or tumor size. Interestingly, pregabalin increased the local infiltration of CD8⁺ and CD4⁺ lymphocytes, natural killer cells and CD8⁺ and CD4⁺ dendritic cells. In contrast, M2-like tumor-associated macrophages and cancer-associated fibroblasts were reduced. Similar to the results of immuno-inflammatory alterations, plasma cytokines such as tumor necrosis factor-α, interleukin (IL)-6, IL-10, IL-13, CC chemokine ligand (CCL)1, CCL2, CCL3, CCL5 and CCL17 decreased, while IL-2, IL-15, CCL19, CCL21, C-X-C motif ligand (CXCL)10, CXCL16 and XCL1 increased by pregabalin.</p> Conclusions <p>These findings suggest that pregabalin increases the proliferative ability of pancreatic cancer cells in vitro without promoting tumor growth in vivo. Additionally, it induces an alteration with an increase in tumor-infiltrating lymphocytes and dendritic cells, along with a decrease in M2-like tumor-associated macrophages and cancer-associated fibroblasts in vivo.</p>