Targeting EGFR signaling to reduce mucus overproduction in lung diseases

Airway mucus is part of innate lung defense, but when production overwhelms clearance, it obstructs airflow and worsens disease. About half of people with chronic obstructive pulmonary disease (COPD) show mucus hypersecretion, and affected patients face a mortality risk about 3.5 times higher than those without it. In asthma, mucus plugs can contribute to fatal airway obstruction. Current options—bronchodilators, hypertonic saline, and mucolytics—mainly relieve symptoms and can cause cardiac, visual, urinary, and metabolic adverse effects. No specific therapy reliably controls mucus overproduction. The review therefore examines whether blocking a convergent inflammatory pathway can reduce mucus without merely treating cough and sputum. Given these challenges, deeper research into safer, more selective epidermal growth factor receptor (EGFR)-targeted approaches is needed.

The review, from researchers in the Department of Respiratory Medicine at Children's Hospital of Chongqing Medical University and affiliated laboratories in Chongqing, China, was accepted on 10 May 2025 and published (DOI: 10.1002/pdi3.70007) in Pediatric Discovery (2026 issue). It examines how EGFR signaling promotes goblet cell hyperplasia (GCH) and mucin production and reviews monoclonal antibodies (MABs), tyrosine kinase inhibitors (TKIs), and nanoparticle-based inhibitors in preclinical and clinical studies. The article is open access and synthesizes mechanistic, animal-model, and human trial evidence, with attention to asthma, COPD, cystic fibrosis (CF), and viral infection.

The review details how EGFR, a receptor tyrosine kinase also known as ErbB1/HER1, is activated by ligands such as epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-α), or by oxidative stress in a ligand-independent manner. Activation converges on Ras/Raf/mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling and the transcription factor Sp1, promoting mucin 5AC (MUC5AC) and mucin 2 (MUC2) transcription; EGFR activation can also suppress the transcription factor FOXA2 and drive GCH. Sp1 further boosts EGF and TGF-α, creating positive feedback. In preclinical models, an anti-EGFR single-chain antibody fragment displayed on ferritin nanoparticles eased asthma features and reduced GCH and mucus. TKIs including gefitinib, erlotinib, and afatinib reduced MUC5AC and mucus in asthma, COPD, acrolein, and viral-infection models; erlotinib restored claudin 1, a barrier protein whose loss accompanies GCH. MABs block the extracellular domain, whereas TKIs compete with adenosine triphosphate (ATP) at the receptor's tyrosine kinase site. A retrospective lung-cancer study suggested gefitinib and afatinib can inhibit mucus hypersecretion before tumor shrinkage. Human evidence remains limited: inhaled BIBW 2948 was poorly tolerated in COPD, while the downstream inhibitor Bio11006 reached phase IIb. The authors emphasize that efficacy must be balanced against skin, gastrointestinal, hepatic, and pulmonary toxicity.

The authors said the central opportunity is to turn a shared inflammatory convergence point into a selective airway therapy. They said EGFR blockade appears to reduce GCH and mucin production across diverse triggers, but they cautioned that existing TKIs carry off-target effects and that no successful EGFR-TKI trial has yet been reported in human asthma or COPD. They said future work should prioritize low off-target molecules, optimized delivery devices, and clinical trials that measure both mucus outcomes and systemic safety in patients.

Clinically, EGFR-targeted drugs could complement bronchodilators and mucolytics by reducing the source of excess mucus rather than only clearing it. The most plausible near-term path is inhaled or airway-selective delivery, which may limit skin, gastrointestinal, hepatic, and pulmonary toxicity associated with systemic TKIs. Patients with severe asthma, COPD with mucus plugs, CF, or virus-driven exacerbations might benefit most, but trials will need to measure mucin burden, lung function, exacerbations, and adverse events. Nanoparticle and antibody-fragment platforms could improve targeting, yet regulators and clinicians will need robust evidence that mucus reduction translates into fewer exacerbations and better survival. The review's implication is clear: EGFR is a promising target, not yet a proven routine treatment.