Disclosed are crystalline free base ansolvate forms of 2-hydroxy-6-((2-(1-isopropyl-1H-pyrazol-5-yl)pyridin-3-yl)methoxy)benzaldehyde (or Compound 1), such as the free base Form I, Form II and Material N. Also disclosed are crystalline free base solvates of 2-hydroxy-6-((2-(1-isopropyl-1H-pyrazol-5-yl)pyridin-3-yl)methoxy)benzaldehyde (or Compound 1).Linvention concerne des formes ansolvates de base libre cristallines de 2-hydroxy-6-((2-(1-isopropyl-1H-pyrazol-5-yl)pyridin-3-yl)méthoxy)benzaldéhyde (ou Composé1), notamment les forme I, forme II et matériau N de base libre. Linvention concerne également des solvates de base libre cristallins de 2-hydroxy-6-((2-(1-isopropyl-1H-pyrazol-5-yl)pyridin-3-yl)méthoxy) benzaldéhyde (ou Composé 1).
