Prophylactic doxycycline (doxy) lessens rash from dacomitinib (D) an EGFR inhibitor with no rash or diarrhea improvement from corticosteroids or probiotics.

e19049 Background: ARCHER 1042 (NCT01465802) was a randomized patient (pt) blinded trial that explored prophylactic interventions to minimize select dermatologic adverse events of interest (SDAEI) and diarrhea toxicities associated with D, an irreversible small molecule PanHER. Methods: In Cohorts I (CI) and II (CII) pts with advanced NSCLC, ≥ 1 prior chemo, ECOG 0–2, were randomized (pt blinded) in CI to (a) D 45 mg daily (QD) plus placebo...