B41-26 Impact of Transbronchial Lung Cryobiopsy on Early Treatment Initiation in Idiopathic Pulmonary Fibrosis

Abstract Rationale Idiopathic pulmonary fibrosis (IPF) requires timely diagnosis and treatment, yet diagnostic confidence based on clinical-radiological assessment alone is often suboptimal, potentially delaying treatment initiation. Transbronchial lung cryobiopsy (TBLC) is a less invasive alternative to surgical lung biopsy (SLB) that may raise diagnostic confidence and facilitate treatment initiation. Nevertheless, its impact on early treatment initiation in clinical practice remains uncertain. Methods We conducted a retrospective single-center cohort study including consecutive patients with IPF who underwent initial evaluation between January 2014 and December 2024 and initiated pirfenidone or nintedanib by November 2025. Diagnoses were reconfirmed according to contemporary international guidelines. The index date was the first pulmonary function test (PFT). Patients with forced vital capacity (FVC) 50% predicted, acute exacerbation of IPF, lung cancer, or significant infection at baseline were excluded. At our institution, TBLC was introduced in 2021; therefore, patients were classified according to the initial evaluation date into the pre-TBLC era (2014-2020) and the post-TBLC era (2021-2024). The co-primary outcomes were between-era differences in (i) time from initial evaluation to antifibrotic initiation and (ii) change in FVC (ΔFVC), calculated as the difference between the FVC at the PFT closest to antifibrotic initiation and that at initial evaluation. The secondary endpoint was the between-era difference in the proportion of patients with an absolute decline in %FVC ≥5% before treatment. Given the shorter follow-up duration in the post-TBLC era, we performed sensitivity analyses excluding patients initiating therapy 1 year and 1.5 years after the initial evaluation. Furthermore, to address potential secular trends (e.g. updated guidelines, increasing experience), outcomes were summarized by calendar periods (2014-2016, 2017-2018, 2019-2020, 2021-2022, 2023-2024). Results We analyzed 220 patients (pre-TBLC era n = 114; post-TBLC era n = 106). In the pre-TBLC era, 15% underwent SLB, whereas in the post-TBLC era, 61% underwent TBLC, enabling histopathological evaluation in a greater proportion of patients. Time to antifibrotic initiation was shorter in the post-TBLC era: median 110 days (IQR 47-386) versus 560 days (176-1334) in the pre-TBLC era (p 0.01). ΔFVC was smaller in the post-TBLC: median 0 mL (IQR −150 to 23) versus −270 mL (−560 to − 63) (p 0.01). The proportion with ≥5% absolute %FVC decline before treatment was lower post-TBLC era (20% vs 56%, p 0.01). Sensitivity analyses and calendar-period analyses were directionally consistent. Conclusion The availability of TBLC was associated with earlier treatment initiation in IPF,owing to its greater feasibility. This abstract is funded by: None