Dive Brief:
- An injectable drug developed by Protagonist Therapeutics and Takeda Pharmaceutical met the goals of a Phase 3 study testing it in a rare blood disorder, likely setting up the companies to discuss an approval application with regulators.
- Results released by the companies Monday showed that significantly more participants in the study responded to the companies’ drug, called rusfertide, than did placebo. Specifically, researchers measured the proportion of patients who no longer needed phlebotomy, a procedure done to remove excess red blood cells.
- Rusfertide is designed to treat polycythemia vera, a cancer in which red blood cells proliferate and cause blood clots and other cardiovascular problems. Nearly 300 patients with uncontrolled polycythemia vera were enrolled in the companies’ trial, called Verify. Patients in both groups continued to receive standard therapy.
Dive Insight:
The positive results for rusfertide are the second Phase 3 success for a drug developed by Protagonist, which in November reported a psoriasis pill it’s developing with Johnson & Johnson also met its trial goals. Protagonist shares rose by as much as 13% Monday before falling back to trade up 3% by mid-morning.
Takeda paid Protagonist $300 million one year ago to gain rights outside the U.S. to rusfertide. Protagonist retained an option to co-promote rusfertide within the U.S. and share profits, should it win regulatory approval. Under the deal, Takeda owes Protagonist a $25 million milestone payment upon completion of the Phase 3 study report.
“We look forward to working with our partner, Takeda, to submit our findings to the regulatory agencies,” said Protagonist CEO Dinesh Patel, in a statement. “Today’s study results also mark a critical inflection point in Protagonist’s decade long journey in the hepcidin program,” he added, referring to the mechanism by which rusfertide is thought to work.
According to the companies, 77% of study participants treated with rusfertide met the trial’s definition for clinical response during weeks 20 to 32, versus just 33% of those on placebo. Treatment was also associated with improved hematocrit control and better patient-reported outcomes.
No new safety findings were reported, with most adverse events mild injection site reactions. Investigators found no evidence of an increased risk of cancer in rusfertide-treated participants, the companies said.
Protagonist and Takeda will report these data in detail at an upcoming medical meeting and submit them to regulatory agencies.
Some 100,000 to 160,000 people are estimated to have polycythemia vera in the U.S. Marked by an elevated proportion of red blood cells, the disease is often treated with the drug hydroxyurea and with phlebotomy. A few other drugs can be used, but don’t specifically address this elevated “hematocrit,” according to Protagonist.
