TDXD is highly emetogenic. Adding low-dose olanzapine to the standard three-drug antiemetic prophylaxis regimen is a transformative strategy that significantly reduces both acute and delayed nausea, making the potent therapy much more tolerable for patients.

A practice gap exists in managing side effects of Trastuzumab-Deruxtecan (TDXD) between specialties. Breast oncologists, with more experience, are far more aggressive with prophylactic anti-emetics and frequent imaging to detect asymptomatic ILD. This proactive approach is a key lesson for lung cancer specialists and others now adopting the drug.

Drawing lessons from T-DXD, experts treat newer exatecan-payload ADCs like RDXD as highly emetogenic from the first dose. Instead of a 'wait and see' approach, they recommend aggressive premedication with a triple-drug antiemetic regimen to prevent nausea and maintain quality of life.

In the DESTINY LUNG-02 trial for HER2-mutant NSCLC, the lower 5.4 mg/kg dose of Trastuzumab-Deruxtecan (TDXD) yielded a 51% response rate, compared to 28% for the higher 6.4 mg/kg dose. This paradoxical outcome was driven by significantly higher toxicity, particularly interstitial lung disease (ILD), at the higher dose, which limited patients' ability to stay on treatment.

To manage the acute GI toxicity of T-DXd, a preemptive three-drug antiemetic combination is recommended. Completely preventing nausea and vomiting is crucial not just for comfort, but for mitigating patient anxiety around chemotherapy and ensuring they can remain on this long-term treatment.

Nausea with TDXD is severe enough that the drug is now considered highly emetogenic. The standard of care is a prophylactic three-drug antiemetic regimen (NK1 antagonist, 5HT3 antagonist, and dexamethasone). Waiting for nausea to occur before treating is a clinical error; prevention is paramount.

New targeted therapies like Zanidatamab and Zolbetuximab show great promise but cause significant side effects like diarrhea and nausea. Their successful clinical adoption hinges on proactive management using detailed guidelines and prophylactic medications, as toxicity can be severe enough to force treatment discontinuation despite the drug's efficacy.

For managing nausea from ADCs like TDXD, a three-drug prophylactic regimen (steroid, 5-HT3 antagonist, NK1 inhibitor) is recommended. For delayed nausea, continuing the 5-HT3 antagonist on days two and three is often effective before needing to add agents like olanzapine.

For nausea associated with the ADC TDXD, clinicians find adding low-dose olanzapine (2.5mg at bedtime) is a highly effective strategy for both acute and delayed nausea. This practical tip improves tolerability beyond standard three-drug prophylaxis.