FDA Approves PharmaEssentia’s Besremi for Adults with Rare Blood Cancer

Editor’s Take: The approval is both a milestone for patients with ET and a label expansion on a previous indication.

The U.S. FDA approved PharmaEssentia’s Besremi (ropeginterferon alfa-2b-njft) for treatment of adults with essential thrombocythemia (ET). This makes Besremi the first new and approved treatment for ET available in the United States in nearly three decades.

The approval applies to patients regardless of genotype or disease status, plus those newly diagnosed and naïve to cytoreductive therapy.

ET is a rare and chronic blood cancer characterized by overproduction of platelets. Patients may require years’ worth of continual disease management, while remaining at risk for serious complications. These include heart attack, stroke, and pulmonary embolism.

Besremi Differs from Standard of Care

Besremi, a long-acting, interferon-based therapy, is already commercially available for treatment of adults with polycythemia vera (PV). The drug uses novel monopegylation technology and an extended half-life to target disease-driving cells in bone marrow. This differs from current therapies that focus primarily on controlling platelet counts and symptoms.

However, PharmaEssentia does say, Besremi is also designed to reduce elevated platelet counts, as well as disease burden.

In June, PharmaEssentia acquired Canadian specialty pharmaceutical company Forus Therapeutics for $36.5 million. This deal had its roots in PharmaEssentia’s 2024 commercial agreement with Forus to license Besremi.

FDA Follows Other Approvals

PharmaEssentia called the FDA approval a “major milestone.” Besremi was previously approved in Japan and Taiwan for ET.

“[This approval] reflects PharmaEssentia’s longstanding commitment to advancing innovative therapies,” PharmaEssentia Founder and CEO Ko-Chung Lin, PhD, said. “We have been working closely with the FDA, healthcare providers, advocacy organizations and payers [on] this important treatment option.”

The FDA’s approval was based on results from a Phase III clinical trial (SURPASS ET). Over a 12-month period, Besremi showed superiority over anagrelide, and reduced occurrence of thromboembolic events.