Clinical potential of inhaled tauractant in patients with progressive pulmonary fibroses

Introduction. Progressive pulmonary fibrosis (PPF) is characterized by relentless decline in lung function, poor prognosis, and limited therapeutic options. Exogenous surfactant is considered a potential pathogenetic agent.

Aim. To evaluate the efficacy and safety of inhaled Surfactant-BL (INN: tauractant, a natural surfactant from bovine lungs) as an add-on to standard therapy in patients with PPF.

Materials and methods. A single-center prospective randomized open-label controlled trial was conducted. 71 patients with PPF were assigned to three groups: surfactant 75 mg (n = 21), 150 mg (n = 19) or control (n = 31). Inhalations were administered twice daily for 10 days.

Results. In the pooled surfactant group, by day 10 respiratory rate decreased from 22 (19–22) to 20 (18–21) breaths/min (p = 0.03) and SpO₂ increased from 93 (85–94)% to 94 (92–96)% (p = 0.028); by day 30, forced vital capacity (FVC) increased from 65 (45–77)% to 73 (64–83)% of predicted (p = 0.05). No dose-dependent differences were observed. In the 150 mg group, transient cough worsening occurred by day 10 (p = 0.013) followed by improvement by day 30 (p = 0.021). In patients with PaO₂/FiO₂ < 300 mmHg, PaO₂ increased by day 30 (p = 0.042), while those with PaO2/FiO2 > 300 mmHg showed increased SpO₂ by day 10 (p = 0.0006). A baseline FVC predicted response (SpO₂ increase ≥ 4%; OR 1.08, 95% CI 1.03–1.14; p = 0.003) with an optimal threshold of 70% predicted (AUC 0.787). In patients with FVC > 70% predicted, surfactant demonstrated advantages over control at day 30 for SpO₂ (95% vs. 93%, p = 0.052) and DLco (52.5% vs. 40.0%, p = 0.046).

Conclusions. Inhaled surfactant represents a pathogenetically justified and effective add-on to standard therapy for PPF. The greatest benefit is achieved in patients with FVC > 70% predicted, hypoxemic respiratory failure, and refractory cough.

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