PHOSPHARE study program shows a safety advantage of Monofer in relation to hypophosphatemia and other FGF23-mediated effects

The first results from the PHOSPHARE program from Pharmacosmos A/S were presented at the annual meeting of the Endocrinology Society [https://www.abstractsonline.com/pp8/#!/5752/presentation/16504]. The studies enrolled 245 patients and investigated the incidence, severity and duration of hypophosphatemia. Both studies met their primary endpoints individually, each showing that iron isomaltoside causes significantly less hypophosphatemia than ferric carboxymaltose. In pooled analyses of both trials, the incidence of severe hypophosphatemia (s-phosphate ?1 mg/dL (0.32 mmol/l)) occurred in 11.3% of ferric carboxymaltose-treated patients compared to 0.0% of iron isomaltoside-treated patients (p<0.0001) and hypophosphatemia defined as serum phosphate <2 mg/dL (0.65 mmol/l), occurred in 74.4% in the ferric carboxymaltose group vs 8.0% in the iron isomaltoside group (p<0.0001). At day 35 when follow-up ended hypophosphatemia persisted in 43.0% of ferric carboxymaltose-treated patients compared to 0.9% of iron isomaltoside-treated patients (p<0.0001). Compared to iron isomaltoside, ferric carboxymaltose also induced changes in FGF23, vitamin D and calcium homeostasis that triggered secondary hyperparathyroidism and appeared to induce elevations in biomarkers of bone turnover that are associated with osteomalacia.

Correction of iron deficiency anaemia was comparable between the two IV irons, as was the incidence of serious or severe hypersensitivity reactions, which was low for both compounds (0.8 % for iron isomaltoside, 1.7% for ferric carboxymaltose)..