A Study of DS-1211b in Individuals With PseudoXanthoma Elasticum

Key Inclusion Criteria: * Signed and dated informed consent * Male or female participants aged 18 to 75 years at screening * Have an established diagnosis of PXE * Fully vaccinated for coronavirus disease 2019 (COVID-19) per current Center for Disease Control and Prevention guidelines Key Exclusion Criteria: * Have a history of bone fracture in the past 6 months * Have a history of active metabolic bone disease, excluding osteopenia or osteoporosis without fragility fracture * Have a history of calcium pyrophosphate deposit disease * Have a history of hypophosphatasia * Have a history of untreated hyperparathyroidism * Participated in another interventional research study in the past 60 days. * Used bisphosphonate in the preceding 12 months or had plans to use bisphosphonate during the study. * Received Vitamin B6 supplementation \>5 mg/day in the month prior to screening and during the study * Initiated or changed dose of Vitamin D in the preceding month prior to screening * Have an alkaline phosphatase \<lower limit of normal (LLN) range * Have a QTcF interval duration \>450 ms at screening * Have moderate to severe renal insufficiency * Are pregnant or breast-feeding women * Are female participants unwilling to use contraceptive methods * Have any elective surgery planned during the study period * Have any other significant condition (medical, psychiatric, social, or medication) that, in the judgment of the Investigator, would prevent full participation or would be inappropriate for the study