• Posted February 26, 2024

New Drug Could Be Big Advance Against Rare Blood Cancer

Polycythemia vera is a rare form of blood cancer with few good treatment options, but that may soon change based on the results of a new clinical trial.

An injected experimental drug called rusfertide appears effective in reducing the excess production of red blood cells that's a hallmark of the disease.

“Rusfertide appears to represent a significant step forward in treating polycythemia vera through its unique approach of limiting the amount of iron available for blood cell production,” said study lead author Dr. Marina Kremyanskaya. She's an associate professor of medicine (hematology and medical oncology) at Icahn Mount Sinai in New York City.

The study was funded by the drug's maker, Protagonist Therapeutics, and published Feb 21 in the New England Journal of Medicine.

Polycythemia vera is very rare, affecting about one to three out of every 100,000 people. It's a chronic illness involving the overproduction of blood cells, and red blood cells in particular, by the bone marrow. People with polycythemia vera develop a thickening of the blood which ups their risk for clots, strokes and heart attack.

Current treatments include clot-preventing aspirin treatment, or drugs that reduce red blood cell counts such as hydroxyurea, interferon and ruxolitinib, the researchers explained in a Mount Sinai news release.

Patients are also often subjected to phlebotomy, a procedure where needles are used to withdraw blood to reduce overall blood volume.

Frequent phlebotomies can be tough on patients both mentally and physically, and can also lower their blood iron levels.

Despite these treatments, polycythemia vera patients can still experience dangerously high levels of red blood cells, upping their odds for complications.

As the researchers explained, rusfertide works by mimicking a liver hormone that helps regulate the amount of iron in blood. The drug helps lower iron levels and the overall production of red blood cells.

The new trial was conducted at 16 medical centers and involved 70 polycythemia vera patients. Patients are able to inject the drug on their own at home.

Over a seven-month treatment period, patients who received rusfertide injections benefited from "improved and sustained control" of their excess red blood cell production, according to the Mount Sinai news release.

Common symptoms of polycythemia vera -- itchy skin, night sweats, difficulty concentrating and fatigue -- were also eased in patients taking the therapy. The drug appeared to be well-tolerated, the study authors added.

Kremyanskaya said rusfertide shows "great promise" against the disease, reducing red blood cell concentrations.

"Just as importantly, it decreased the need for repeat phlebotomies, with some patients remaining virtually free of the procedure for more than two and a half years,” she noted.

A phase 3 clinical trial is planned, the researchers said.

More information

Find out more about polycythemia vera at Johns Hopkins Medicine.

SOURCE: Icahn Mount Sinai, news release, Feb. 21, 2024