A Multicenter, Multinational, Extension Study to Evaluate the Long-Term Efficacy and Safety of BMN 190 in Patients With CLN2 Disease

BMN 190 is a recombinant form of human tripeptidyl peptidase 1 (TPP1), the enzyme deficient
in patients with CLN2 disease (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, and improve the symptoms
of disease. The Phase 1/2 study (190-201) evaluated the efficacy and safety of doses up to
300 mg/every other week (qow) BMN 190 in patients with CLN2. The dose and regimen for this
study (190-202) are based on the results of the 190-201 study. The rationale for this phase 2
extension study is to provide patients who complete the 190-201 study with the option to
continue BMN 190 treatment. The 190-202 study is an open label extension protocol to assess
long-term safety and efficacy.

Inclusion Criteria:

- Must have completed 48 weeks in Study 190-201.

- Is willing and able to provide written, signed informed consent. Or, in the case of
patients under the age of 18 (or other age as defined by regional law or regulation),
provide written assent (if required) and have written informed consent, signed by a
legally authorized representative, after the nature of the study has been explained,
and prior to performance of research-related procedures.

- 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.

- If female, of childbearing potential, must have a negative pregnancy test at the
Screening Visit and be willing to have additional pregnancy tests done during the
study.

Exclusion Criteria:

- Has had a loss of 3 or more points in the combined motor and language components of
the Hamburg CLN2 rating scale between Baseline of Study 190-201 and the Study
Completion visit in Study 190-201 and would not benefit from enrolling in the study in
the Investigator's discretion.

- Has a score of 0 points on the combined motor and language components of the Hamburg
CLN2 rating scale.

- Is pregnant or breastfeeding, at Baseline, or planning to become pregnant (self or
partner) at any time during the study.

- Has used any investigational product (other than BMN 190 in 190-201), or
investigational medical device, within 30 days prior to Baseline; or is required to
use any investigational agent prior to completion of all scheduled study assessments.

- Has a concurrent disease or condition that would interfere with study participation,
or pose a safety risk, as determined by the Investigator.

- Has any condition that, in the view of the Investigator, places the patient at high
risk of poor treatment compliance or of not completing the study.