Preferred Systemic Glucocorticoid for Deruxtecan-Induced ILD
For trastuzumab deruxtecan-induced interstitial lung disease, systemic corticosteroids (typically oral or intravenous prednisolone/methylprednisolone at 1-2 mg/kg/day) should be initiated promptly for grade ≥2 ILD, with the specific steroid type being less critical than rapid initiation and appropriate dosing based on severity. 1, 2
Evidence-Based Approach
The available evidence does not specify superiority of one particular glucocorticoid formulation over another for T-DXd-induced ILD. However, the management framework is clear:
Grade-Based Steroid Dosing
- Grade 1 ILD: Drug interruption with close monitoring; oral corticosteroids may be considered 3
- Grade 2 ILD: Permanent discontinuation of T-DXd with oral corticosteroids (typically prednisolone 0.5-1 mg/kg/day) 1, 2
- Grade 3-4 ILD: Permanent discontinuation with high-dose intravenous corticosteroids (methylprednisolone 1-2 mg/kg/day or equivalent) 4, 1
Practical Steroid Selection
While the evidence doesn't mandate a specific glucocorticoid, clinical practice typically employs:
- Oral therapy: Prednisone or prednisolone for outpatient management of lower-grade ILD
- Intravenous therapy: Methylprednisolone for hospitalized patients with severe (grade 3-4) ILD requiring more aggressive intervention
The choice between oral versus IV administration depends on severity and clinical setting rather than inherent superiority of one glucocorticoid molecule over another.
Critical Management Considerations
Timing is more important than steroid type. The multidisciplinary guidance emphasizes that prompt initiation of corticosteroids upon ILD diagnosis is crucial for preventing progression to fatal outcomes 1, 2. The fatal-event rate for T-DXd-related ILD is approximately 2.2%, making early intervention essential 5.
Steroid-Refractory Cases
If patients fail to improve after 48 hours of corticosteroid therapy, escalation to second-line immunosuppression should be considered, including infliximab, mycophenolate mofetil, or IV immunoglobulin 4.
Important Caveats
Glucocorticoid use carries inherent risks in ILD patients. Recent data suggests that while corticosteroids are standard treatment for drug-related pneumonitis, they may paradoxically be associated with decreased lung function parameters and potentially accelerated ILD progression in certain contexts 6. This underscores the importance of:
- Using the lowest effective dose
- Tapering appropriately once improvement occurs
- Balancing infection risk (which increases with prolonged high-dose steroids) against disease control 7
The evidence base for glucocorticoid efficacy in drug-related pneumonitis relies primarily on retrospective studies and expert consensus rather than randomized controlled trials 4, but this remains the standard of care given the lack of superior alternatives and clinical experience supporting benefit in most cases.