Small clinical trial led by Dana-Farber Cancer Institute builds on Salk’s foundational research on vitamin D receptor and tumor microenvironment
- Highlights
- Preclinical studies at the Salk Institute laid the foundation for a question now being tested in patients: Can a vitamin D-based therapy “reprogram” a pancreatic tumor’s protective microenvironment, making tumors more vulnerable to therapeutic treatments?
- A clinical trial led by the Dana-Farber Cancer Institute now demonstrates that a synthetic vitamin D analog can be administered safely in combination with standard-of-care chemotherapy and effectively reprogram the supporting pancreatic tumor microenvironment.
- This work also provides early evidence that vitamin D analogs can enhance chemotherapy response and improve survival, especially in patients with high tumor vitamin D receptor expression.
A small clinical trial led by Dana-Farber Cancer Institute researchers put a Salk Institute idea to the test in patients: that activating the vitamin D receptor can help reshape the protective environment surrounding pancreatic tumors in ways that could make the notoriously difficult-to-treat cancer more vulnerable to therapeutic treatments.
In the study, published May 25, 2026, in Nature Cancer, patients with previously untreated metastatic pancreatic cancer received standard chemotherapy with or without paricalcitol, a vitamin D analog that is already FDA-approved for other uses. In patients who received paricalcitol orally or intravenously, the combination was found to be safe and to reduce activation of fibroblasts in the tumor microenvironment, validating Salk’s preclinical findings.
The trial was not intended to measure how well the approach works in treating pancreatic cancer, yet the researchers noted improved chemotherapy responses and increased progression-free survival at one year among patients who received paricalcitol plus chemotherapy. In addition, they found that patients with high vitamin D receptor expression and who received paricalcitol had the longest overall survival.
“By using vitamin D analogs to engage the body’s own natural system for dampening fibrotic and inflammatory responses, we can enable other therapies to do their job.”