Interstitial Lung Disease (ILD) and Pneumonitis

ILD and pneumonitis, including Grade 5 cases, have been reported with ENHERTU 5.4 mg/kg (pooled clinical studies; N=491)1,2,a,b

The majority were Grade 1 or 2 (n=52/62)

  • In pooled clinical studies in HER2+ mBC, ILD/pneumonitis occurred in 13% of patients (n=62/491); fatal events occurred in 1.4% of patients (n=7/491)
  • Median time to first onset was 5.5 months (range: 1.1-20.8) with ENHERTU

In DESTINY-Breast03, no Grade 4 or 5 adjudicated drug-related ILD/pneumonitis events were observed

Adjudicated as drug-related ILD, n (%) ENHERTU
5.4 mg/kg (n=257)
3.6 mg/kg (n=261)
Grade 1 7 (2.7) 4 (1.5)
Grade 2 18 (7.0) 1 (0.4)
Grade 3 2 (0.8) 0
Grade 4 0 0
Grade 5 0 0
All Grades 27 (10.5) 5 (1.9)

aILD includes events that were adjudicated as ILD for ENHERTU: pneumonitis, interstitial lung disease, organizing pneumonia, pneumonia, and pulmonary mass. For T-DM1: pneumonitis, interstitial lung disease, organizing pneumonia, and pulmonary embolism.1

bGrade 5=fatal cases.2

Symptom identification and investigation at the first sign of ILD/pneumonitis are key to diagnosis and monitoring

Signs and symptoms of ILD/pneumonitis1

  • Cough
  • Dyspnea
  • Fever
  • New or worsening respiratory symptoms

Promptly investigate evidence of ILD/pneumonitis3

  • Diagnosis of ILD/pneumonitis requires exclusion of other causes
  • Evaluation may include:
    • High-resolution CT
    • Pulmonologist consultation
    • Blood culture and CBC
  • All events of ILD/pneumonitis, regardless of severity or seriousness, should be followed until resolution including after drug discontinuation
  • Advise patients of the potential benefits and risks of treatment and to contact HCP immediately to report any of these symptoms

Investigation may be prompted by incidental findings on routine scans when checking for progression or symptomatic findings

For asymptomatic ILD (Grade 1)1

  • Consider corticosteroid treatment (eg, ≥0.5 mg/kg/day prednisolone or equivalent)
  • Interrupt ENHERTU until resolved to Grade 0, then:

For symptomatic ILD (Grade 2 or greater)1

  • Promptly initiate systemic corticosteroid treatment (eg, ≥1 mg/kg/day prednisolone or equivalent)
    • Continue for at least 14 days followed by gradual taper for at least 4 weeks
  • Permanently discontinue ENHERTU in patients who are diagnosed with any symptomatic ILD/pneumonitis

Talk to your patients to raise awareness and help identify symptoms1

  • Advise patients to contact their healthcare provider immediately for any of the symptoms shown above
  • Inform patients of the risks of severe, life-threatening, or fatal ILD
  • Advise patients to read the FDA-approved patient labeling: Download the Medication Guide

Potential questions to ask your patients to help with identification of ILD4,5

  • Have you been coughing recently? Is it a dry cough?
  • Have you had any shortness of breath, especially during or after physical activity?
  • Have you experienced any new breathing or respiratory problems?
  • If you already have respiratory problems, have they gotten worse?
  • Have you had a fever?
  • Have you been feeling tired?
  • Have you lost weight?

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CBC, complete blood count; CT, computed tomography; FDA, Food and Drug Administration; HCP, healthcare professional; HER2, human epidermal growth factor receptor 2; mBC, metastatic breast cancer; T-DM1, ado-trastuzumab emtansine.