Participants must:

• Provide written or electronic consent after the nature of the study has been explained, and prior to any research-related procedures
• Be diagnosed with ENPP1 Deficiency supported by prior genetic identification of biallelic ENPP1 mutations
• Be male or female, 18 to < 65 years old at screening
• Have a PPi level at screening that meets the requirement
• Be willing and able to complete all aspects of the study in the opinion of the researcher
• Agree to provide access to relevant medical records

People being treated with statins or proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors must:

• Be on stable doses for 6 months prior to enrollment through end of study unless previously cleared

Women of child-bearing potential must:

• Have a negative serum pregnancy test at screening

Women of child-bearing potential and partners of fertile males who are of child-bearing potential must agree to:

• Use 1 highly effective form of contraception and a barrier method from at least 1 month before the first dose through 30 days after last dose of treatment
• Not donate ova from the period following the first dose through 30 days after last dose of treatment

Males who are sexually active must agree to:

• Use condoms from the period following first dose through 30 days after the last dose of treatment
• Not donate sperm from the period following the first dose through 30 days after last dose of treatment