Soluble ferric pyrophosphate (SFP), a late-stage investigational iron-delivery drug, reduced the use of erythropoietin-stimulating agents (ESAs) by 37% in hemodialysis (HD) patients while maintaining target hemoglobin levels and decreasing iron stores, new data show.
The data are from the PRIME study, a nine-month, prospective, randomized, placebo-controlled, double-blind trial that randomized 108 patients to dialysate containing SFP or conventional dialysate (placebo group). In all study subjects, ESA doses were titrated to maintain hemoglobin (Hb) in a target range of 9.5-11.5 g/dL. The baseline ESA dose was similar for the SFP and placebo groups (9,483 and 9,206 U/week, respectively). Hb values were 10.9 and 11.1 g/dL in the SFP and placebo arms, respectively. The placebo group required 37% more ESA than the SFP group to maintain hemoglobin in a target range of 9.5-11.5 g/dL.
According to the drug developer, Rockwell Medical, Inc. of Wixom, Mich., the results support the company’s belief that SFP will demonstrate efficacy in its Phase 3 efficacy studies, called CRUISE-1 and CRUISE- 2.
SFP is a unique iron compound that is administered to the HD patient via dialysate, replacing the 5-7 mg of iron lost during a dialysis treatment. SFP is introduced into the sodium bicarbonate concentrate that subsequently is mixed into dialysate. Once in the dialysate, SFP crosses the dialyzer membrane and enters the bloodstream where it immediately binds to transferrin and is delivered to the bone marrow, similar to the way dietary iron is processed in the human body. This is in contrast to IV iron products indicated for the treatment of iron-deficiency anemia. IV iron is sequestered in the liver due to the anemia of inflammation, before releasing gradually into the bloodstream, explained SFP inventor Ajay Gupta, MD, Chief Scientific Officer for Rockwell Medical.
All FDA approved IV iron products for the treatment of iron deficiency anemia are iron-carbohydrate complexes, and it is the carbohydrate moiety that triggers the anaphylactoid or hypersensitivity reactions, Dr. Gupta said. SFP does not contain carbohydrate, he said, pointing out that not a single anaphylactoid reaction has occurred in patients being given SFP, even after approximately 60,000 human doses administered in clinical trials. With IV iron products, these anaphylactoid reactions do occur, and in one called ferumoxytol, patients have to remain under observation for at least 30 minutes after administration, leading to significant inconvenience and restrictions as to where the drug can be given.