TYPE: New Zealand Research Study
STATUS: In recruitment
GCF CONTRIBUTION: $15,000

Does the Gastric Acid Altering Effects of Proton Pump Inhibitors Effect Capecitabine Pharmacokinetics?

Capecitabine is a tablet form of chemotherapy commonly used to treat a variety of cancers affecting the gut and breast. Many patients who are on capecitabine are also on proton pump inhibitors (PPI) (examples include omeprazole/losec and pantoprazole/panzop-relief) for treatment of reflux and indigestion.

Recently, concerns have been raised that people who use PPIs while on capecitabine have poorer outcomes compared to those who were not on PPIs. One possible explanation for this observation is that reduced acidity in the stomach caused by PPIs may alter how the capecitabine tablet is absorbed into the body. At present, we do not know if this is true and there are no good-quality studies that can clarify this important question.

APEC is a simple study that could test the potential impact of pantoprazole (a common PPI prescribed in New Zealand) on capecitabine absorption among patients undergoing capecitabine treatment for gut and breast cancer. Capecitabine and PPI usage is particularly high in New Zealand, making this study both urgent and relevant.

This study seeks to answer a concern around day to day oncology practice that may have significant implications for thousands of patients with gut cancers across New Zealand and around the world. In the short term, this study will contribute to a pool of scientific evidence that would either support or refute the concerns raised about the effects of PPI on the pharmacokinetics of capecitabine. This may also provide direction for future research into the question. In the long term, this study, alongside other related studies, will hopefully provide definitive answers on whether to permit or discourage the concurrent use of proton pump inhibitors and capecitabine.

GCF is grateful to the Estate of Ernest Davis & The Ted and Mollie Carr Endowment Trust proudly managed by Perpetual Guardian, for their support of this research.