Which of the following best describes the mechanism by which nintedanib slows progression in idiopathic pulmonary fibrosis (IPF)?
- A Selective inhibition of TGF-β1 signalling
- B Inhibition of multiple tyrosine kinase receptors (PDGFR, VEGFR, FGFR) reducing fibroblast proliferation and differentiation ✓
- C Anti-inflammatory effect via IL-13 pathway blockade
- D Lysyl oxidase inhibition preventing cross-linking of collagen
Correct answer: B. Inhibition of multiple tyrosine kinase receptors (PDGFR, VEGFR, FGFR) reducing fibroblast proliferation and differentiation
Explanation
Nintedanib is a multi-target tyrosine kinase inhibitor that blocks PDGF, VEGF, and FGF receptor signalling, thereby reducing fibroblast recruitment, proliferation, and transformation into myofibroblasts — the key cells driving fibrosis in IPF. The INPULSIS trial showed it reduced FVC decline by approximately 50% versus placebo. Pirfenidone acts through TGF-β pathway modulation and anti-fibrotic/anti-inflammatory effects. Lysyl oxidase inhibition is a target under investigation but not the nintedanib mechanism.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.