Bone marrow hypoplasia and lymphocyte depletion (spleen, thymus, lymph nodes) in all species; immunosuppressive
“In conclusion, fedratinib-related effects on the bone marrow (hypoplasia) and lymphoid tissues (lymphocyte depletion in the spleen, thymus and lymph nodes) in all three species are likely symptoms of exaggerated pharmacology and indicate clear immunosuppressive properties of fedratinib”
Whole-body distribution in rats incl. melanin-containing skin and eyes; ocular elimination ~40 days
“Radiolabeled [14C]‐fedratinib was distributed throughout the whole body of the rat, including to the skin and eyes (i.e. melanin‐containing tissues). Elimination from the eyes was approximately 40 days.”
✓ VerifiedFDA multi-discipline review, p. 58Source ↗
Modality-specific risk
Thiamine transporter (ThTr-1/ThTr-2) inhibition and thiamine levels, assessed in vitro and in rats
“The ability of fedratinib to inhibit human thiamine transporters ThTr‐1 and ThTr‐2 was evaluated using biochemical assays, and to change thiamine levels was assessed in a GLP‐ compliant 28‐day repeat‐dose pharmacodynamic study in rats.”
✓ VerifiedFDA multi-discipline review, p. 60Source ↗