Interstitial Lung Disease (ILD) and Pneumonitis

ILD and pneumonitis were reported in DESTINY-Breast03; the majority of events were Grade 1 or 2 in the ENHERTU arm (n=25/27)1,2

No Grade 4 or 5 adjudicated drug-related ILD/pneumonitis events were observeda

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)

aGrade 5=fatal cases.2

Updated analysis (July 2022)
  • Overall incidence of ILD was 15% in the ENHERTU arm and 3% in the T-DM1 arm
  • No Grade 4 or 5 adjudicated drug-related ILD/pneumonitis events were observed

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/pneumonitis4

  • 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

Monitor patients with moderate renal impairment more frequently; a higher incidence of Grade 1 and 2 ILD/pneumonitis has been observed in these patients1

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 ILD5,6

  • 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.