FDA rejects rare disease drug, asks for prefilled syringe info

FDA Building 2
PharmaEssentia is confident it can resubmit "in an expeditious manner." (FDA)

The FDA has rejected PharmaEssentia’s request for approval of a treatment for a rare blood cancer. PharmaEssentia needs to provide more information about the instructions for the prefilled syringes used to administer the pegylated interferon.

Ropeginterferon alfa-2b, which is sold in the EU as Besremi, comes in prefilled syringes for injection under the skin. The drug is designed to bind to interferon-alpha/beta receptors, thereby triggering processes that drive a reduction in red blood cell production in the bone marrow. As the rare disease polycythaemia vera is defined by excess red blood cells, PharmaEssentia sought to win FDA approval in the indication.

The FDA knocked back the approval request in a complete response letter. In disclosing the setback, PharmaEssentia cited two explanations for the rejection, including a FDA request for additional data about the administration format.

A PharmaEssentia spokesperson provided more details. “The FDA has asked for more information about how the provided Instructions For Use for our prefilled syringe will help patients and healthcare providers administer the treatment. Importantly, no new data was requested about the clinical profile of the product,” the spokesperson wrote in an emailed statement.

PharmaEssentia also attributed the rejection to a delay to a planned FDA preapproval inspection of its manufacturing plant in Taiwan due to travel restrictions imposed to curb the spread of COVID-19. 

Shares in PharmaEssentia, which trades on the Taipei Exchange, fell after the news, but U.S. General Manager Meredith Manning is still optimistic. “We are confident that we can work with the Agency to address the requests highlighted in the response letter and resubmit in an expeditious manner,” Manning said in a statement.

PharmaEssentia won approval for the drug in the EU in 2019. Manning said PharmaEssentia remains “fully committed” to making ropeginterferon alfa-2b available to polycythaemia vera patients in the U.S., where the disease affects 44 to 57 per 100,000 people, according to the National Organization for Rare Disorders.