Association of concurrent acid-suppression therapy with survival outcomes and adverse event incidence in oncology patients receiving erlotinib.

PURPOSE

Acid-suppression therapy is known to decrease the systemic exposure of erlotinib. The erlotinib prescribing information recommends staggering dosing with a histamine-2 receptor antagonist (H2RA) and avoiding concurrent use of a proton pump inhibitor (PPI). This retrospective analysis evaluated the frequency of concurrent acid-suppression therapy in oncology patients receiving erlotinib and its association with outcomes.

METHODS

All patients prescribed erlotinib within UC San Diego Health System between February 26, 2011, and February 28, 2014, were assessed for eligibility, survival outcomes and adverse events.

RESULTS

Of the 76 patients in the analysis, 24 were prescribed both a PPI and an H2RA with erlotinib therapy (31.6 %). The two patient groups, with (n = 24) and without PPI/H2RA (n = 52), were similar in clinical characteristics and erlotinib dose. One patient received an H2RA therapy alone and was excluded from the analysis; no one received PPI therapy alone. Patients receiving erlotinib alone had a longer median progression-free survival (PFS) compared to patients with concurrent PPI/H2RA therapy (11.0 months vs. 5.3 months; P = 0.029). Overall survival (OS) and incidence of rash and/or diarrhea did not correlate with use of acid-suppression therapy.

CONCLUSION

Nearly one-third of patients received acid-suppression therapy. Patients treated with erlotinib and PPI/H2RA therapy had shorter PFS, but similar OS and adverse event profile compared to those who did not receive acid-suppression.