The impact of drug-drug interactions between palbociclib and proton pump inhibitors (PPI) on clinical outcomes of patients with HR+, HER2- early breast cancer: an exploratory analysis of the PALLAS study

Dr Elisa Agostinetto reports whether concomitant use of PPIs could have affected clinical outcomes in patients treated with palbociclib in PALLAS. The PALLAS study randomised 5796 patients to receive either 2 years of palbociclib with adjuvant ET or ET alone and it is known that the addition of palbociclib did not improve invasive disease-free survival compared to adjuvant ET alone.

Of 2840 patients treated with palbociclib + ET, 533 (18.8%) had concomitant PPI and palbociclib intake. This exploratory analysis did not demonstrate a statistically significant relationship between concomitant use of PPIs and palbociclib and survival outcomes of patients in the PALLAS trial. Nonetheless, careful consideration of concomitant medications and of drug-drug interactions is important when studying novel agents in the adjuvant breast cancer setting.

Reference:

Agostinetto E, SABCS 2023, # PO1-01-08