Final findings from the CONTROL trial: Strategies to reduce the incidence and severity of neratinib-associated diarrhea in patients with HER2-positive early-stage breast cancer

BackgroundNeratinib is an irreversible pan-HER tyrosine kinase inhibitor approved for HER2-positive early-stage and metastatic breast cancer. Diarrhea is the most frequent side effect and the most common reason for early discontinuation. The phase II CONTROL trial investigated antidiarrheal prophylaxis or neratinib dose escalation (DE) for prevention of diarrhea. We present complete study results including final data for two DE strategies.MethodsPatients who completed trastuzumab-based adjuvant therapy received neratinib 240mg/day for 1 year. Early cohorts investigated mandatory prophylaxis with loperamide, then additional budesonide or colestipol. Final cohorts assessed neratinib DE over the first 2 (DE1) or 4 weeks (DE2). The primary endpoint was incidence of grade ≥3 diarrhea. Health-related quality of life (HRQoL) was assessed using FACT-B and EQ-5D-5L.Results563 patients were enrolled into six cohorts. All strategies reduced grade ≥3 diarrhea with the lowest incidence in DE1 (DE1 13%; colestipol+loperamide [CL] 21%, DE2 27%; budesonide+loperamide [BL] 28%; loperamide [L] 31%; colestipol+loperamide as needed [CL-PRN] 33%). Diarrhea-related discontinuations occurred early and were lowest in DE1 (DE1 3%; CL 4%; DE2 6%; CL-PRN 8%; BL 11%; L 20%). More patients stayed on neratinib for the prescribed period versus historical controls. Prior pertuzumab use did not affect rates of grade ≥3 diarrhea, diarrhea-related discontinuations, or treatment duration. Early transient reductions in HRQoL scores were observed.ConclusionsThese complete results from CONTROL show improved neratinib tolerability with proactive management at the start of therapy. Two-week neratinib DE with loperamide as needed was particularly effective.ClinicaltrialsGov registration numberNCT02400476.