PharmaEssentia Announces Japan Approval of High-Dose Dosing Regimen for BESREMi®
Tuesday, March 03, 2026
PharmaEssentia has announced that Japan’s Ministry of Health, Labour and Welfare (MHLW) has approved a high-dose dosing regimen for ropeginterferon alfa-2b, marketed as BESREMi®, as an alternative schedule in the product label.
BESREMi® received approval in Japan in March 2023 for the treatment of adult patients with PV who are resistant to or intolerant of existing therapies. Under the earlier recommended schedule, treatment started at 100 mcg, with increases of 50 mcg every two weeks up to a maximum of 500 mcg. The newly approved regimen enables patients to achieve the clinical maintenance dose more rapidly, which may support earlier disease control.
It holds orphan drug designation in the United States for the treatment of adult patients with PV. It has received regulatory approval in more than 40 countries, including from the European Medicines Agency in 2019, the US Food and Drug Administration in 2021, and Japan’s Pharmaceuticals and Medical Devices Agency in 2023. The product was developed by PharmaEssentia, which retains global intellectual property rights across all approved and investigational indications.
Ropeginterferon alfa-2b-njft is approved by the U.S. Food and Drug Administration for the treatment of adults with PV and is marketed as BESREMi®. The company has submitted a supplemental biologics licence application to the US regulator seeking to expand the label to include essential thrombocythaemia (ET).
Clinical findings indicate that the high-dose regimen enables patients to reach the target maintenance dose more quickly, supporting earlier therapeutic benefit. The approval is based on data from the domestic Phase III A23-301 trial, an open-label and uncontrolled study conducted in Japanese patients with polycythaemia vera (PV). Treatment began at 250 mcg and, if tolerated, was increased to 350 mcg at two weeks and 500 mcg at four weeks. Thereafter, the medicine was administered subcutaneously every two weeks for up to 24 weeks. At Week 24, the complete haematologic response rate was 57.1%.
The decision was supported by strong complete haematologic response results achieved with the optimised one-month dosing schedule. This approach allows patients to reach the 500 mcg target dose significantly faster than under the previously approved regimen, which required gradual dose escalation over approximately four to four and a half months.
The safety profile, including serious adverse events, was consistent with earlier experience and comparable between dosing strategies.
Source: pharmaessentia.com
