A Safety, Tolerability, and Efficacy Study of Intracerebroventricular BMN 190 in Pediatric Patients < 18 Years of Age With CLN2 Disease

BMN 190 is a recombinant form of human tripeptidyl peptidase 1 (TPP1), the enzyme deficient
in patients with CLN2 diseases (also known as classical late-infantile CLN2, cLINCL, or
Jansky-Bielschowsky disease), a form of Batten Disease. As an enzyme replacement therapy
(ERT), BMN 190 is designed to restore TPP1 enzyme activity. BMN 190 is designed to reduce the
progressive, pathologic accumulation of lysosomal storage material. 190-203 is a Phase 2
open-label, multicenter study that will evaluate the safety, tolerability, and efficacy of
BMN 190 in pediatric patients < 18 years of age with CLN2 disease. Study drug dosing will be
determined by the patient's age and administered via intracerebroventricular (ICV) infusion
every other week (qow), for a duration of 144 weeks.

Enrollment over the age of 2 years is complete.

Inclusion Criteria:

- Diagnosis of CLN2 disease as determined by TPP1 enzyme activity (dried blood spot) in
the fibroblasts and leukocytes available at Screening

- Quantitative clinical assessment of the Hamburg motor-language aggregate score 3-6 at
Screening on CLN2 disease motor-language scale, as defined in the Ratings Assessment
Guideline

- < 18 years of age at the time of informed consent

- Written informed consent from parent or legal guardian and assent form subject, if
appropriate

- Males and females who are of reproductive age should practice true abstinence, defined
as no sexual activity, during the study and for 6 months after the study has been
completed (or withdrawal from the study). If sexually active and not practicing true
abstinence, males and females of reproductive age must use a highly effective method
of contraception while participating in the study.

- Ability to comply with protocol required assessments (ICV implantation, drug
administration, laboratory sample collection, EEG, ECG, MRI, etc.)

Exclusion Criteria:

- Presence of another inherited neurological disease, e.g., other forms of CLN or
seizures unrelated to CLN2 disease (patients with febrile seizures may be eligible)

- Presence of another neurological illness that may have caused cognitive decline (e.g.,
trauma, meningitis, hemorrhage) or interference with disease rating (autism) before
Screening

- Presence of percutaneous feeding tube placement prior to enrollment

- Has received stem cell, gene therapy, or ERT

- Presence of contraindications for neurosurgery (e.g., congenital heart disease, severe
respiratory impairment, or clotting abnormalities)

- Presence of contraindications for MRI scans (e.g., cardiac pacemaker, metal fragment
or chip in the eye, aneurysm clip in the brain)

- Episode of generalized motor status epilepticus within 4 weeks before the First Dose
visit

- Severe infection (e.g., pneumonia, pyelonephritis, or meningitis) within 4 weeks
before the First Dose visit (enrollment may be postponed)

- Presence of ventricular abnormality (hydrocephalus, malformation)

- Presence of ventricular shunt

- Has known hypersensitivity to any of the components of BMN 190

- Has received any investigational mediation within 30 days before the first infusion of
study drug or is scheduled to receive any investigational drug other than BMN 190
during the course of the study

- Has a medical condition or extenuating circumstance that, in the opinion of the
investigator, might compromise the subject's ability to comply with the protocol
required testing or procedures or compromise the subject's well being, safety, or
clinical interpretability

- Pregnancy any time during the study; a female subject judged by the investigator to be
of childbearing potential will be tested for pregnancy