Injectafer Double Dose—Double Profit and Double Risk, and Dosage Discrepancy

Santa Clara, CAHypophosphatemia, an abnormally low level of phosphate in the blood, may be due to longer term use or excess of certain drugs such as bisphosphonates, including Injectafer, but that may depend upon researchers conducting the clinical trials and the amount of the iron-deficiency drug treatment.

The FDA approved Injectafer in July 2013 after a number of submissions by Luitpold Pharmaceuticals, the U.S. partner of Vifor Pharma, the Swiss drug manufacturer. The approval was based on two large clinical trials conducted by Luitpold, which studied more than 3,500 patients, of which 1,800 were treated with Injectafer.

Right on the heels of its approval, the following “new drug” information was published (July 25) in PubMedCentral (more below) by Luitpold:

Injectafer… is the first high-dose, non-dextran IV iron indicated for a broad patient population. Approximately 7.5 million people in the U.S. have iron-deficiency anemia. Current therapies are limited to treating the condition in patients with chronic kidney disease, those who require infusions over the course of several hours, or those who need multiple dosing sessions.

A single dose of up to 750 mg of ferric carboxymaltose can be administered undiluted as an IV push injection at a rate of 100 mg/minute, or it may be given as an IV infusion in up to 250 mL of 0.9% sodium chloride injection over the course of at least 15 minutes.

(PubMed Central is a “ repository of content primarily from two sources: peer reviewed journals that overall have met the National Library of Medicine’s standards for PMC and peer reviewed author manuscripts deposited in compliance with the public access policy of NIH or other collaborating funders. )

Injectafer Overdose Danger

According to Medscape.com, only two doses of Injectafer should be administered. But plaintiffs in a number of lawsuits claim they had multiple doses of the drug to treat iron deficiency. For example, Celeste White, who filed her complaint in the U.S. District Court for the Eastern District of Pennsylvania, claims she received six injections and developed severe HPP. 

According to Infusion Associates, Injectafer restores iron levels in two administrations of 750 mg — although dosage may vary according to the patient’s weight. Each therapy should be scheduled seven days apart. But iron overload is possible: a condition that could increase the risk of liver disease, diabetes mellitus, hypothyroidism, osteoarthritis, osteoporosis, heart attack, and/or heart failure.

(On its website, Infusion Associates states it is a highly skilled team of healthcare professionals” with a “research department, including physicians, certified nurse coordinators, nurse practitioners, and pharmacists who collaborate with pharmaceutical companies and local specialists to offer new treatment opportunities and aide in the understanding of various illnesses and treatment options through clinical trials.)

Clinical Trial Conflict of Interest and Dosing Discrepancy

Drug companies are typically reluctant to fund studies unless they are sure of an outcome, and that can be biased. For instance, in a lengthy article penned by Iain Macdougall and other researchers, he received consultancy fees, lecture fees, honoraria, and research grant funding from Vifor Pharma, the Injectafer maker. The July 2014 article “Safety of intravenous iron formulations: facts and folklore” concluded that several studies “report the safety, ease, convenience and efficacy of complete or near-complete replacement doses of IV iron administered in a single setting (total dose infusion over 15–60 minutes)”. In other words, one dose.

JAMA in July 2020 published the results of clinical trials that were favorable to Injectafer, finding a lower incidence of hypophosphatemia over 35 of the random trials. At least four researchers reported receiving personal fees during the study and personal fees paid by Luitpold Inc outside their submitted work. 

But other researchers (for example, studies conducted in Norway and Austria) found that the benefits of Injectafer can be outweighed by the serious side effect of severely low phosphorus levels known as hypophosphatemia (HPP).

Drug Maker Profits

In a BusinessWire press release, MarketWatch noted that growing awareness of iron drugs in North America is the major cause for the growth of global iron drugs market. The global Iron Drugs market size is projected to skyrocket by 2026. Vifor claims that Injectafer hit Blockbuster status one year earlier than anticipated. Could double dosages be key in such profits?