The Food and Drug Administration (FDA) has approved ropeginterferon alfa-2b-njft (Besremi) for the treatment of adults with polycythemia vera. Ropeginterferon alfa-2b-njft is the first interferon for treating polycythemia vera and the first FDA-approved medication for this condition that can be taken regardless of the patient's treatment history. It is uniquely formulated to be long lasting and is administered subcutaneously every two weeks.
Ropeginterferon alfa-2b-njft received orphan drug designation, as polycythemia vera is a rare disease. According to the National Organization for Rare Disorders, polycythemia vera is estimated to affect approximately 44 to 57 per 100,000 people in the United States. It occurs most often in individuals over the age of 60 years but can affect individuals of any age.
Polycythemia vera is one in a group of blood cancers known as myeloproliferative neoplasms, in which too many red blood cells are produced in the bone marrow. Often, white blood cells and platelets are also elevated. In polycythemia vera, the DNA of a developing stem cell in the bone marrow develops an acquired mutation, which leads to uncontrolled production of blood cells. The presence of excess blood cells increases the risk of abnormal clots and bleeding. Some patients with polycythemia vera may develop myelofibrosis, acute myeloid leukemia, or myelodysplastic syndromes.
Ropeginterferon alfa-2b-njft is thought to reduce blood cell production by attaching to interferon alfa receptors in the bone marrow, setting off a downstream signaling chain reaction through activating Janus kinase 1 and tyrosine kinase 2, as well as transcription proteins.
The drug's effectiveness and safety were evaluated in a multicenter, single-arm trial of 51 adults with polycythemia vera. The trial lasted 7.5 years, with an average length of treatment of five years. The outcome measure was achievement of a complete hematologic response (red blood cell volume less than 45% without a recent phlebotomy, normal white cell and platelet counts, normal spleen size, and no blood clots). Overall, 61% of patients had a complete hematologic response.
The labeling of ropeginterferon alfa-2b-njft, like that of other interferon alfa products, contains a boxed warning that it can cause or aggravate neuropsychiatric, autoimmune, ischemic, and infectious disorders, which can be life-threatening or fatal. Contraindications for use include the existence of, or history of, severe psychiatric disorders, particularly severe depression, suicidal ideation, or attempted suicide; hypersensitivity to interferons, including interferon alfa-2b or any inactive ingredients of ropeginterferon alfa-2b-njft; moderate or severe (Child-Pugh B or C) hepatic impairment; and history or presence of active serious or untreated autoimmune disease. The drug is also contraindicated in immunosuppressed transplant recipients.
Other warnings and precautions include depression and suicide; endocrine toxicity; cardiovascular toxicity; decreased peripheral blood counts; hypersensitivity reactions; pancreatitis; colitis; pulmonary toxicity; ophthalmologic toxicity; hyperlipidemia; hepatotoxicity; renal toxicity; dental and periodontal toxicity; dermatologic toxicity; and the need to avoid driving or operating machinery if experiencing dizziness, somnolence, or hallucinations. Ropeginterferon alfa-2b-njft may also cause fetal harm. The most common adverse effects are influenza-like illness, arthralgia, fatigue, pruritus, nasopharyngitis, and musculoskeletal pain.
Nurses should assess patients for potential drug interactions using a drug database. Other myelosuppressive drugs and narcotics, hypnotics, and sedatives should be avoided while taking ropeginterferon alfa-2b-njft because these drugs can produce additive adverse effects. Nurses should also assess if any coadministered drugs are substrates of cytochrome P-450 (CYP450) enzymes. Interferons can suppress these enzymes, resulting in elevated levels of the substrate. If the patient is receiving any CYP450 substrates, nurses should confirm that the substrate is not one with a narrow therapeutic index, where an elevated circulating level could produce serious adverse effects. Those drugs will likely need to have their doses decreased. Nurses should also check the patient's estimated glomerular filtration rate to confirm that it is greater than 30 mL/min to decrease the risk of renal toxicity. Both pregnancy testing to confirm the patient is not pregnant and use of an effective method of contraception are recommended in patients of reproductive age to prevent fetal harm.
Nurses should closely monitor patients receiving ropeginterferon alfa-2b-njft for any persistently severe or worsening signs or symptoms of neuropsychiatric, autoimmune, ischemic, and infectious disorders. Ropeginterferon alfa-2b-njft comes in a prefilled syringe with a separate needle. Nurses should teach patients how to store, prepare, and administer the drug subcutaneously. Patients should also review the instructions for use that come with each prescription. The package insert diagrams are also helpful.
For complete prescribing information for ropeginterferon alfa-2b-njft, go to http://www.accessdata.fda.gov/drugsatfda_docs/label/2021/761166s000lbl.pdf.