Vonicog alfa, sold under the brand names Vonvendi and Veyvondi, is a medication used to control bleeding in adults with von Willebrand disease (an inherited bleeding disorder). It is a recombinant von Willebrand factor.The most common adverse reactions are generalized itching, vomiting, nausea, dizziness, and vertigo.Vonicog alfa should not be used in the treatment of Hemophilia A.In the UK it is available only via a named patient access program.Vonicog alfa was approved for medical use in the United States in December 2015, in the European Union in August 2018, and in Australia in April 2020. It was granted orphan drug designations in both the United States and the European Union. Medical uses
Vonicog alfa is indicated in adults with von Willebrand Disease (VWD), when desmopressin (DDAVP) treatment alone is ineffective or not indicated for the

Treatment of haemorrhage and surgical bleeding
Prevention of surgical bleeding. Adverse effects
The following side effects may occur during treatment with vonicog alfa: hypersensitivity (allergic) reactions, thromboembolic events (problems due to the formation of blood clots in the blood vessels), development of inhibitors (antibodies) against von Willebrand factor, causing the medicine to stop working and resulting in a loss of bleeding control.
The current gold standard for diagnosis is DNA sequence analysis, which can detect WAS and the related disorders XLT and XLN in 95% of patients and carriers. Classification
Jin et al. (2004) employ a numerical grading of severity: This score, which ranges from 0 to 5, may have clinical utility for predicting disease severity. Those with higher WAS scores (e.g., 5) at younger ages (e.g., age less than 5 years old), are thought to be at highest risk for increased morbidity and mortality related to their condition. As individuals can develop more WAS-related symptoms (e.g. autoimmune disease, malignancy) with age, ones WAS score can increase over time. A lower WAS score may be more compatible with conservative management versus higher WAS scores that may favor intervention with treatments such as hematopoietic stem cell transplant. Treatment
Hematopoietic stem cell transplant
Treatment of Wiskott–Aldrich syndrome depends on the severity of the disease. WAS is primarily a disorder of the blood-forming tissues, so in cases of severe disease (WAS score 3–5) the only widely available curative treatment currently available is a hematopoietic stem cell transplant (HCT). In this procedure stem cells are harvested from umbilical cord blood, bone marrow, or peripheral blood following treatment with medications that cause stem cells to leave the bone marrow and circulate systemically. The best outcomes are with HLA-identical or similar donors (often siblings).