Paricalcitol Boosts Pancreatic Cancer Chemo Response in Trial — SkimNews
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- Dana-Farber Cancer Institute researchers led a 36-patient randomized trial combining paricalcitol — a vitamin D analog already FDA-approved for kidney disease — with gemcitabine and nab-paclitaxel in previously untreated metastatic pancreatic cancer, finding the combination tolerable though five of 12 oral-dose patients developed elevated blood calcium that was managed by dose reduction.
- Ronald Evans at the Salk Institute discovered the nuclear receptor superfamily that paricalcitol targets, and earlier lab work from his group showed vitamin D analogs could reverse the activation of cancer-associated fibroblasts around pancreatic tumors, the preclinical foundation for the clinical trial.
- Paricalcitol with chemotherapy produced a partial response in 10 of 24 patients (42%) versus 1 of 12 (9%) on placebo, and five paricalcitol patients remained progression-free at one year compared with none in the placebo group — signals the researchers caution were not the trial's primary endpoint.
- Paired tumor biopsies analyzed with multiplex immunofluorescence and spatial transcriptomics showed paricalcitol reduced fibroblast activation inside tumors and increased T cell infiltration, evidence the drug actually remodeled the protective microenvironment in patients rather than acting only in the lab.
- Patients with high vitamin D receptor levels in their tumors who received paricalcitol showed the longest overall survival, a biomarker clue the team says must be validated in larger studies designed to test survival and patient selection.
- The findings were published in Nature Cancer on October 3, 2026, with the authors framing the work as a road map for larger trials that could establish a new stromal-remodeling treatment standard for one of the deadliest cancers.
Why it matters: Pancreatic cancer wraps its tumors in a dense fibrotic shield that blocks chemo and immune attack, and standard therapy leaves roughly half of metastatic patients progressing within months — paricalcitol is already FDA-approved, cheap to repurpose, and here showed a 42% vs 9% response gap with a survival signal in receptor-high tumors, meaning a confirmatory trial could quickly identify a subgroup who finally respond to treatment.
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