History
Results of a Phase I clinical trial were reported in 2016.In December 2019, enfortumab vedotin was approved in the United States for the treatment of adult patients with locally advanced or metastatic urothelial cancer who had previously received a programmed cell death receptor-1 (PD-1) or programmed death ligand 1 (PD-L1) inhibitor and a platinum-containing chemotherapy.Enfortumab vedotin was approved based on the results of a clinical trial that enrolled 125 patients with locally advanced or metastatic urothelial cancer who received prior treatment with a PD-1 or PD-L1 inhibitor and platinum-based chemotherapy. The overall response rate, reflecting the percentage of patients who had a certain amount of tumor shrinkage, was 44%, with 12% having a complete response and 32% having a partial response. The median duration of response was 7.6 months.The U.S. Food and Drug Administration (FDA) granted the application for enfortumab vedotin accelerated approval, priority review designation, and breakthrough therapy designation. The FDA granted the approval of Padcev to Astellas Pharma US Inc.In July 2021, the FDA approved enfortumab vedotin for adults with locally advanced or metastatic urothelial cancer who have previously received a programmed death receptor-1 (PD-1) or programmed death-ligand (PD-L1) inhibitor and platinum-containing chemotherapy, or; are ineligible for cisplatin-containing chemotherapy and have previously received one or more prior lines of therapy.
Christianson syndrome is an X linked syndrome associated with intellectual disability, microcephaly, seizures, ataxia and absent speech. Presentation
Onset of symptoms is normally within the first year of life with truncal ataxia and seizures. The head is small (microcephaly). Common facial abnormalities include:
Long narrow face
Prominent nose
Prominent jaw
Large ears
Open mouth
Thick eyebrowsOther common features include:
Uncontrolled drooling
Abnormal eye movementsThe associated intellectual disability is usually in the profound range. Those affected often have a happy demeanor with frequent smiling and spontaneous laughter. Genetics
This condition is caused by mutations in the SLC9A6 gene. This gene is located on the long arm of the X chromosome (Xq26.3). The gene encodes a sodium/hydrogen exchanger located in the endosomes. Mutations in this gene cause a rise in the pH of the endosomes.How this causes the clinical features is not known presently. The inheritance of this condition is X-linked dominant. Diagnosis
The diagnosis may be suspected on clinical grounds.It is made by sequencing the SLC9A6 gene. Differential diagnosis
Angelman syndrome
Spinocerebellar ataxia type 29

Management
There is presently no curative treatment. Management is supportive. Epidemiology
The prevalence is not known but this is considered to be a rare disease. History
This condition was first described in 1999. The causative mutation was discovered in 2008. == References ==