Guidelines Issued for Zanidatamab Diarrhea Management
Medical professionals have released new clinical guidance to address diarrhea in patients receiving zanidatamab-based regimens.
Updated on Oct. 12, 2026 in Cancer
Clinical experts have published new management strategies for patients experiencing diarrhea while undergoing zanidatamab-based treatment. The guidelines aim to assist care teams in distinguishing treatment-related side effects from other gastrointestinal issues.
Why it matters
Managing gastrointestinal toxicity is essential for patient adherence during cancer treatment, particularly as zanidatamab regimens become more common. These protocols help medical providers distinguish early-onset treatment diarrhea from immune-mediated colitis.
Clinical protocols indicate that diarrhea most frequently occurs within the first week of zanidatamab-based treatment. These guidelines emphasize that loperamide prophylaxis allows for the de-escalation of antidiarrheal therapy.
The details
The guidance addresses the complexities of treating patients in the United States, where FOLFOX chemotherapy is the standard, compared to the capecitabine-based regimens common in the HERIZON-GEA-01 trial. Care teams are now advised to contact patients within the initial days of treatment to monitor symptoms closely.
Timeline
Diarrhea associated with zanidatamab-based regimens typically manifests during the first week of treatment.
The Big Picture
This guidance reflects the maturation of treatment protocols derived from the HERIZON-GEA-01 trial. It marks a shift toward standardized supportive care as experimental regimens move into broader clinical practice.
Patients undergoing these treatments should coordinate with their care teams to manage symptoms early in the first week of their regimen. Understanding these guidelines can help individuals better communicate side effects and avoid unnecessary therapy adjustments.
The takeaway
Proactive communication with a clinical team during the first week of treatment is the most effective way to manage potential gastrointestinal side effects. Patients should ask their providers about loperamide protocols before beginning new regimens.
Further reading
For more information on oncology supportive care, visit the Cancer section.
Source note: This article includes information reported by OncLive.
