Continuation Protocol to Protocol BBCO-001

This will be a multi-center, randomized withdrawal, open-label, non-treatment concurrent control, parallel group study. Patients completing protocol BBCO-001 will be offered the opportunity to enter into this 12-month randomized withdrawal protocol.

This will be a multi-center, randomized withdrawal, open-label, non-treatment concurrent control, parallel group study. Patients completing protocol BBCO-001 will be offered the opportunity to enter into this 12-month randomized withdrawal protocol. Eligible patients will be randomized to one of the following treatment arms: * Treatment Arm 1: active treatment; continuation of 30 g IV Cabaletta once a week over an additional 52 weeks. * Treatment Arm 2: no-treatment concurrent control; discontinuation of IV Cabaletta and follow-up over 52 weeks. IV Cabaletta will be administered once a week to patients in Treatment Arm 1. All patients, regardless of treatment arm allocation, will undergo the same safety and efficacy assessments during the monthly site visits.