Single Dose Injectafer May Avoid Health Risks Linked to Iron Deficiency Treatment When Multiple Doses Are Injected

A new study indicates the recently approved single dose version of the iron infusion Injectafer may be effective at preventing anemia for six months, without the need for additional injections, which may help avoid severe injuries that have been linked to multiple courses of the iron deficiency anemia (IDA) treatment.

Injectafer (ferric carboxymaltose) was first introduced in 2013, as a two-dose iron infusion for adults with anemia, who are not able to be treated with an oral iron supplement and have non-dialysis dependent chronic kidney disease. Patients have typically been given at least two 750 mg infusions, spaced at least seven days apart. However, many individuals have required multiple iron infusion courses if symptoms of the anemia persisted.

After case reports and independent studies confirmed that some users were experiencing severe and potentially life-threatening drops in blood phosphate levels due to Injectafer side effects, the FDA required a label update in February 2020, warning about the risk of a medical condition known as hypophosphatemia (HPP), and urging doctors to monitor serum phosphate levels, especially among patients who required repeat courses of the treatment.

In May, the drug maker Daichi Sankyo announced the FDA had granted approval for a 1,000 mg single-dose Injectafer treatment, avoiding the need for repeat courses of the infusions as part of the standard treatment.

According to findings of new research published in the July 2021 issue of the medical journal Current Developments in Nutrition, researchers from India report that nearly 70% of women who received a single intravenous dose of Injectafer went without anemia for six months, suggesting far less doses of Injectafer may be needed to manage anemia than the drug maker originally recommended when the treatment was introduced.

The study involved 100 women from northern India, who were given a single dose Injectafer infusion of about 900 mg between August 2018 and February 2019. Participants were then evaluated for mean hemoglobin levels at six weeks and six months.

Researchers were able to follow up with 57 of the 100 women, and their findings indicate that 69.4% were still non-anemic after six months.

If the single dose Injectafer infusion proves successful at treating iron deficiency anemia without the need for repeated courses, it may help users avoid the risk of hypophosphatemia (HPP), which can cause symptoms like severe fatigue, muscle weakness, bone and joint pain, mental confusion, repeated hospitalizations and other complications. In cases of persistent or severe HPP, the drops on blood phosphorous levels may cause other serious conditions like osteomalacia, bone fractures, cardiac arrhythmias, cardiac arrest, respiratory failure, kidney failure, rhabdomyolysis, seizures or death.

Daiichi Sankyo and its American Regent subsidiary currently face several hundred Injectafer lawsuits filed by individuals who have experienced these problems, alleging that the drug makers knew about the HPP risk before the iron infusion was ever introduced, yet it waited years before disclosing the risk to patients and the medical community.

Plaintiffs allege that if the Injectafer FDA label warnings had been updated earlier, many severe injuries could have been avoided by monitoring blood phosphate levels or limiting the courses of the iron infusion treatment.