The FDA approval of the siRNA drug Redemplo caps off a tumultuous 12 months for Arrowhead, whose partnership with Sarepta caused its own stock to drop during the gene therapy maker’s safety troubles this summer.
The downdrift in which Arrowhead Pharmaceuticals found itself this summer as a result of its association with Sarepta Therapeutics reversed direction Tuesday as the company announced the FDA approval of plozasiran—now Redemplo—to reduce triglycerides in adults with familial chylomicronemia syndrome.
Redemplo, a small interfering RNA (siRNA) therapy, is the first FDA-approved drug in its class for patients with the rare metabolic disease. Familial chylomicronemia syndrome (FCS) is characterized by triglyceride levels that can reach 10 to 100 times higher than normal range, putting patients at high risk of acute, recurrent and potentially fatal pancreatitis, according to the company’s press release. Redemplo is approved as an adjunct to diet.
Redemplo is also Arrowhead’s first FDA-approved medicine. “The FDA approval of REDEMPLO is a transformational milestone for Arrowhead,” CEO Chris Anzalone said in a prepared statement. “This is a proud moment for all those involved in the discovery and development process and represents new hope for the estimated 6,500 people in the U.S. living with genetic or clinical FCS.”
The drug’s approval and subsequent launch also “marks the beginning of a new chapter in our journey—one rooted in unwavering commitment to delivering life-changing therapies to patients with serious diseases,” Anzalone continued.
Redemplo’s approval in FCS is based on the Phase III PALISADE study, which met its primary endpoint and key secondary endpoints, including reductions in triglycerides and APOC3, a key regulator of triglyceride metabolism. In PALISADE, a 25-mg dose of Redemplo elicited “deep and durable” reductions in triglycerides—a median drop from baseline of 80% compared to 17% in a pooled placebo group, according to Arrowhead. The treatment group also experienced fewer cases of acute pancreatitis than the placebo arm.
Arrowhead has set a price of $60,000 per year and committed to a pricing model “that creates one consistent price across current and future indications,” executives said on the company’s investor call Tuesday afternoon. Redemplo is currently being studied in Phase III for severe hypertriglyceridemia and Phase II for dyslipidemia.
It’s been an active 12 months for Arrowhead. Last November, the company licensed multiple clinical and preclinical siRNA programs to Sarepta in a deal worth $825 million upfront, as well as a potential $10 billion in a series of consistent payments tied to enrollment and other clinical development milestones. In July, Sarepta announced a strategic restructuring and pipeline pivot away from its legacy gene therapies and toward these assets.
Then, the safety saga around Sarepta’s gene therapy Elevidys exploded, and Arrowhead’s shares fell 12% in the course of about a month.
“We have been caught in that downdraft as well, unfortunately,” Anzalone told BioSpace in August. “And it’s not unreasonable. I think that people were curious about Sarepta’s ability to perform on the partnership.”
With its first FDA approval in the books—and some stability on the Sarepta front with an updated label for Elevidys—the winds appear to be blowing in the right direction for Arrowhead.
