Professional · Issue 4 · 2026-10-15
ETI-Era Therapy De-escalation: Real-World Data Suggest Short-Term Safety, But Important Gaps Remain
Editorially reviewed research summaries, context, and limitations.
Cynthia D Brown, Kevin J Psoter, Kathryn A Sabadosa, et al.
Summary: The HERO-2 study is a 12-month prospective observational study of 709 people with CF (age ≥12) taking elexacaftor/tezacaftor/ivacaftor (ETI), examining whether self-reported discontinuation of one or more chronic daily therapies (CDTs) is associated with worse pulmonary outcomes. Using inverse probability weighting to adjust for baseline differences, the study found no statistically significant association between CDT discontinuation and increased pulmonary exacerbations or lung function decline over 12 months. Notably, 41.5% of participants reported having discontinued at least one CDT at baseline, underscoring how common this practice already is in the real world.
Why it matters: As ETI has dramatically improved symptoms and lung function for many people with CF, patients and clinicians are naturally questioning whether the full burden of chronic airway clearance, inhaled antibiotics, mucolytics, and other therapies remains necessary. This study provides the first prospective observational data on outcomes associated with CDT discontinuation in the ETI era, directly addressing a question that registries and cross-sectional surveys cannot answer well. The finding that de-escalation was not detectably harmful over 12 months is clinically meaningful and may help inform shared decision-making conversations, even if it cannot definitively endorse discontinuation.
Expert perspective: The study is methodologically thoughtful for real-world research: prospective design, registry-linked outcomes, remote enrollment broadening geographic reach, and inverse probability weighting to address confounding. However, several limitations deserve careful attention. CDT discontinuation was self-reported at baseline through a patient-facing app, meaning the specific therapies discontinued, the timing, and adherence patterns are incompletely characterized. Twelve months may be insufficient to detect slow lung function trajectories or infrequent exacerbations in a relatively well population on ETI. Selection bias is a genuine concern: patients who feel well enough to stop therapies may differ systematically from those who do not, and inverse probability weighting adjusts only for measured confounders. The study population is self-selected through a remote app-based platform, which may over-represent engaged, health-literate patients with milder disease or stronger disease control on ETI. The confidence intervals around both primary outcomes, while including zero, are wide enough that clinically meaningful harms cannot be excluded. This study does not establish safety of CDT discontinuation; it establishes that in this sample, over this timeframe, no detectable harm was observed. That is a meaningful and useful finding, but it should be communicated with appropriate nuance. Longer follow-up, better characterization of which CDTs are stopped, and more diverse enrollment are needed before de-escalation can be broadly recommended.
Relevance: Cystic Fibrosis
Source: https://pubmed.ncbi.nlm.nih.gov/42554296/
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