No immunotoxicity studies; no immune-system findings in general toxicity studies
“Furthermore, there were no findings suggestive of effects on the immune system in general toxicity studies conducted in mice for up to 13 weeks, rats for up to 26 weeks, or monkeys for up to 39 weeks.”
✓ VerifiedFDA multi-discipline review, p. 65Source ↗
Biodistribution & persistence
Rat: highest in liver, intestine, thyroid, stomach, pituitary; radioactivity in melanin-rich eye tissues sustained up to 12 weeks
“Following a single oral dose of radiolabeled relugolix to rats, the highest radioactivity was observed in liver, intestine, thyroid, stomach and pituitary gland. Radioactivity in the eyes, mainly localized to the melanin rich tissues - anterior and posterior parts, was detected at 4 h and sustained for up to 12 weeks post-dose.”
✓ VerifiedFDA multi-discipline review, p. 33Source ↗
“In repeat-dose studies, phospholipidosis in multiple organs was observed in both rats (≥ 100 mg/kg) and monkeys (≥ 1.5 mg/kg) at exposures 18 times and 0.6 times, respectively, the clinical exposure at the human recommended dose based on AUC.”
✓ VerifiedFDA multi-discipline review, p. 33Source ↗