FDA Approves First Interferon Therapy for Rare Blood Cancer

Early this March, the FDA had rejected Taiwan-based PharmaEssentia’s treatment for rare blood cancer.  In a complete response letter issued to the company, the agency asked for additional data about the administration format of Besremi, an engineered interferon treatment.

The reason for the CRL was attributed to COVID-related travel restrictions, which halted the agency a pre-approval inspection of the company’s manufacturing facility in Taiwan. After eight months, the company has eventually bagged the FDA’s nod.

On November 12th, the FDA approved Besremi (ropeginterferon alfa-2b-njft) for the treatment of adults with polycythemia vera (PV). The rare cancer originates from a disease-initiating stem cell in the bone marrow resulting in a chronic increase of red blood cells, white blood cells, and platelets. The excess cells thicken the blood, slowing blood flow and increasing the chance of blood clots.

“We are incredibly proud to deliver on our goal of bringing treatments like BESREMi to the polycythemia vera community where there is clear unmet need for more effective, tolerable and durable treatments to preserve patients’ health and well-being,” said Ko-Chung Lin, Ph.D., Co-Founder, and CEO of PharmaEssentia and inventor of the treatment.

“As we begin working closely with the community to integrate this important treatment into clinical practice, we also continue to expand our scientific efforts to unlock the full potential of our pioneering molecule.”

First Approved Tretament for PV

Besremi was greenlit by the EMA in 2019 and has also notched regulatory approvals in Taiwan and South Korea. In the US, the drug had earlier received the orphan drug designation. With the latest approval, the drug becomes the first FDA-approved medication for PV that patients can take regardless of their treatment history, and the first interferon therapy specifically approved for PV.

“Over 7,000 rare diseases affect more than 30 million people in the US. Polycythemia vera affects approximately 6,200 Americans each year,” said Ann Farrell, M.D., Director of the Division of Non-Malignant Hematology in the FDA’s Center for Drug Evaluation and Research. “This action highlights the FDA’s commitment to helping make new treatments available to patients with rare diseases.”

“The reality of living with a rare and chronic cancer like polycythemia vera is that it is often underrecognized, and the limited treatments available cannot properly address the disease beyond the symptoms. Our community welcomes the FDA approval of a new treatment that has the potential to deliver what has been unavailable for so many patients hoping for a better outlook,” said Ann Brazeau, CEO of MPN Advocacy and Education International.

Innovative, Engineered Interferon Treatment

Besremi is an innovative monopegylated, long-acting interferon. With its unique pegylation technology, the drug has a long duration of activity in the body and is aimed to be administered once every two weeks or longer until hematologic parameters are stabilized, allowing flexible dosing that helps meet the individual needs of patients.

The approval was based on the evaluation of the safety and efficacy of Besremi in a multicenter, single-arm trial that lasted 7.5 years. The efficacy was measured by evaluating the number of patients who achieved a complete hematological response, registering a red blood cell volume of less than 45% without recent phlebotomy, normal white cell counts, and platelet counts, a normal spleen size, and no blood clots.

Results showed that around 61% of patients with PV experienced a complete hematological response. Importantly, 80% of patients achieved a hematological response (based on objective laboratory parameters only, with the exclusion of normal spleen size and thrombosis).

The most common adverse reactions (incidence >40%) were influenza-like illness, arthralgia, fatigue, pruritis, nasopharyngitis, and musculoskeletal pain. Serious adverse reactions (incidence > 4%) were urinary tract infection, transient ischemic attack, and depression.

Author

Rajaneesh K. Gopinath