The HOW LONG trial is an international, multicenter, Phase IV randomized clinical trial evaluating the optimal duration of adjunctive systemic corticosteroids in immunocompromised adults with severe Pneumocystis jirovecii pneumonia (PCP) who demonstrate early clinical recovery. Participants who no longer require supplemental oxygen by day 10 of corticosteroid therapy are randomized to discontinue corticosteroids at day 10 (or hospital discharge, if earlier) versus continue corticosteroids for a total of 21 days. The trial assesses whether earlier discontinuation reduces steroid-related complications while maintaining clinical outcomes.
Age ≥18 years
Proven or probable Pneumocystis jirovecii pneumonia
Severe PCP requiring supplemental oxygen (e.g., ≥4 L/min or ≥35% FiO₂ to maintain SpO₂ ≥94%)
Planned or receiving adjunctive systemic corticosteroid therapy for severe PCP
Persistent hypoxemia or ongoing oxygen requirement at day 10
Clinical deterioration prior to randomization
Treating clinician determines steroids must be continued or stopped immediately for medical reasons
Anticipated death within 48 hours