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BESREMi® (Ropeginterferon alfa-2b) deemed safe and efficacious by the US FDA

March 15th 2021
The US Food & Drug Administration (FDA) issued a complete response letter for the drug BESREMi® with the active pharmaceutical ingredient Ropeginterferon alfa-2b, in which the FDA confirms the efficacy and safety of the drug. This assessment was based on the clinical development program by the European rare disease company AOP Orphan.

Vienna, 15.03.2021. On March 12, 2021, according to PharmaEssentia Corp., the FDA in the United States issued a so-called Complete Response Letter in respect to the submission of BESREMi® (Ropeginterferon alfa-2b) for the treatment of polycythaemia vera, a rare form of blood cancer. The Complete Response Letter confirms the safety and efficacy of BESREMi® in compliance with FDA regulations. The Complete Response Letter comes almost a year after PharmaEssentia's application to the FDA and is based on a clinical study program by AOP Orphan, which started in Europe in 2010. AOP Orphan congratulates PharmaEssentia on achieving this important milestone.

“Today’s FDA confirmation of BESREMi®’s safety and efficacy, based on AOP Orphan’s clinical study program and scientific knowledge, attests to the quality of work at our company." says Dr. Rudolf Widmann, Chief Therapeutics Development Officer and Member of the Board of the Vienna-based company AOP Orphan. This is the first of AOP Orphan’s ambitious US registration projects. This achievement speaks not only to the scientific expertise and clinical development know-how of AOP Orphan, but also to the efficacy of the product. 

Final approval of BESREMi® in the US can take place after successful inspection of the manufacturing facilities of PharmaEssentia by the FDA officials. Due to the COVID-19 pandemic, they were as of yet unable to travel to Taiwan to inspect the manufacturing facilities, a requirement for any new drug approval by the FDA. 

Clinical studies conducted by AOP Orphan

Ropeginterferon alfa-2b is a specifically modified pegylated Interferon alpha 2b invented by PharmaEssentia’s CEO KC Lin. In 2009, AOP Orphan in-licensed the exclusive rights for the clinical development and commercialization of Ropeginterferon alfa-2b in polycythaemia vera and other myeloproliferative neoplasms (MPNs) for Europe, the Commonwealth of Independent States (CIS), and Middle Eastern markets. Ever since, AOP Orphan has continually invested its hematology and drug development know-how along with considerable funds into development of an injection pen for patients’ at-home self-administration. Several clinical studies have been conducted by the company leading to a successful marketing authorization of BESREMi® for the treatment of polycythaemia vera: in the EU in February 2019, in Switzerland in 2020, and in Israel in 2021. 

Besides achieving high rates of complete hematologic responses including freedom of phlebotomy in 8 out of 10 patients, BESREMi® offers the possibility of disease modification and eventually operational cure in a subset of patients. This is exemplified by a decrease of mutant JAK2 allele burden (the disease-causing oncogene) from 37.3% at baseline to 7.3% in patients receiving Ropeginterferon alfa-2b, while an increase from 38.1% to 42.6% in the control group receiving hydroxyurea/best available therapy was observed (p<0.0001).

Polycythaemia vera patients in approximately 20 European countries are already being treated with Ropeginterferon alfa-2b. AOP Orphan is continuously working on increasing access to this life-saving drug for many more patients and continues the clinical development of BESREMi®. 

About BESREMi® 

BESREMi® is a long-acting, mono-pegylated proline interferon (ATC L03AB15). Its unique pharmacokinetic properties offer a new level of tolerability. BESREMi® is designed to be conveniently self-administered subcutaneously with a pen once every two weeks, or monthly after stabilization of hematological parameters. This treatment schedule is expected to lead to overall better safety, tolerability and adherence compared to conventional pegylated interferons. Ropeginterferon alfa-2b was discovered by PharmaEssentia, a long-term partner of AOP Orphan. In 2009, AOP Orphan in-licensed the exclusive rights for clinical development and commercialization of Ropeginterferon alfa-2b in PV and other MPNs for European, Commonwealth of Independent States (CIS), and Middle Eastern markets. 

For the EMA Summary of Product Characteristics please visit:

About AOP Health

The brand AOP Health incorporates several companies: The international Healthcare Group is the European pioneer for integrated therapies for rare diseases and in critical care. Over the past 25 years, the company has become an established provider of integrated therapy solutions from its headquarters in Vienna, its subsidiaries and representative offices throughout Europe and the Middle East, as well as through partners worldwide. This development has been made possible by a continually high level of investment in research and development on the one hand and a highly consistent and pragmatic orientation towards the needs of all our stakeholders on the other - especially the patients and their families as well as also the doctors and care professionals treating them. 

Press Contact.

Mag. Nina Roth, MAS

Head of Corporate Communications


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