Open-label Study of VTS-270 in Participants With Neurologic Manifestations of Niemann-Pick Type C1

Exclusion Criteria

• •A participant is ineligible for study participation if, at the Baseline Visit:
• •1. Participants discontinued from Study VTS301 for AEs.
• •2. Participant has an unresolved serious adverse event (SAE) for which treatment with VTS-270 has been halted.
• •3. Female participants who are pregnant or nursing.
• •4. Participants with suspected infection of the central nervous system or any systemic infection.
• •5. Participants with a spinal deformity that could impact the ability to perform a LP.
• •6. Participants with a skin infection in the lumbar region within 2 months of study entry.
• •7. Any of the following laboratory abnormalities at the Baseline Visit:
• •1. Neutropenia, defined as an absolute neutrophil count of less than 1.5 × 10\^9/liter (L).
• •2. Thrombocytopenia (platelet count of less than 75 × 10\^9/L).
• •3. Activated partial thromboplastin time or prothrombin time prolonged by greater than 1.5 × the upper limit of normal (ULN) or known history of a bleeding disorder.
• •4. Aspartate aminotransferase or alanine aminotransferase (ALT) greater than 4 × ULN.
• •5. Anemia: hemoglobin greater than 2 standard deviations below normal for age and gender.
• •6. Estimated glomerular filtration rate less than 60 milliliters (mL)/minute/1.73 square meter (m\^2) calculated using the modified Schwartz formula (Schwartz et al., 2009) for participants aged 4 through 17 years old or using the Chronic Kidney Disease Epidemiology Collaboration equation formula for participants aged 18 years or older.
• •8. Evidence of obstructive hydrocephalus or normal pressure hydrocephalus.
• •9. Recent use of anticoagulants (in past 2 weeks prior to first dose \[Study Day 0\]).
• •10. Active pulmonary disease, oxygen requirement, or clinically significant history of decreased blood oxygen saturation, pulmonary therapy, or requiring active suction.
• •11. Participants who, in the opinion of the investigator, are unable to comply with the protocol or have medical conditions that would potentially increase the risk of participation.