BioMarin Pharmaceutical Inc. announced interim results from its Phase 1/2 pivotal study for BMN 190 or cerliponase alfa, a recombinant human tripeptidyl peptidase 1 (rhTPP1), to treat of patients with late infantile CLN2 disease, a form of Batten disease. Interim data indicates that in all nine of the BMN 190 patients who have been followed for at least six months and up to 15 months, the treatment appears to show stabilization of the disease compared to the natural history based on a standardized measure of motor and language function. The primary end point of the study is a standardized mobility and language score using a CLN2-specific rating scale.

The scale separately measures performance of mobility and language with normal function in each being a score of three and no function being a score of zero. The higher score possible is six. According to data from a natural history study of the disease, patients generally lose one point every six months and generally lose most language and mobility functioning over a two to four year period in this rapidly progressive disease.

In the nine BMN 190 patients treated for more than six months and up to 15 months, six patients showed no net change in their CLN2 rating scale score, while the other three showed a decline of one point. In addition, seven of the nine patients in the BMN 190 study for more than six months were matched to between one and 12 individuals from the natural history data set according to baseline age and disease severity. (For two of the BMN 190 patients, there is no matched patient in the natural history database based on age and disease severity.) All seven BMN 190 patients with six months of treatment and at least one control match had better walk/talk scores as of their last evaluation than their natural history counterparts.

There is no approved treatment that can prevent, stop, or reverse CLN2 disorder. Palliative care to reduce seizures and physical rehabilitative care to help children retain muscle function for as long as possible are currently the available treatment options for patients with this rare disease. The Phase 1/2 pivotal study is an open-label, dose-escalation study in patients with late infantile CLN2 disease, a form of Batten disease.

The primary objectives are to evaluate the safety and tolerability of BMN 190 or cerliponase alfa and to evaluate effectiveness using a CLN2 disorder-specific rating scale score in comparison with natural history data after 48 weeks of treatment. Secondary objectives are to evaluate the impact of treatment on brain atrophy in comparison with CLN2 natural history after 48 weeks of treatment and to characterize pharmacokinetics and immunogenicity. The study enrolled 24 subjects at five clinical sites for a planned treatment duration of 48 weeks.

Complete results are expected in the fourth quarter of 2015.