Vitamin D analog may weaken pancreatic cancer's protective shield

A Dana Farber and Salk Institute trial of 36 patients with metastatic pancreatic cancer found paricalcitol, a vitamin D analog, can be safely combined with chemotherapy and reduces fibroblast activation in the tumor microenvironment. Partial responses occurred in 42% of those receiving the drug, with the longest survival among patients whose tumors had high vitamin D receptor levels.

• 36 patients received gemcitabine plus nab-paclitaxel with paricalcitol or placebo
• 10 of 24 patients (42%) on paricalcitol had a partial response
• 5 of 12 on oral paricalcitol had elevated blood calcium, managed by dose cuts
• Paricalcitol reduced fibroblast activation and increased T-cell infiltration