La Jolla Pharmaceutical Company announced that it has started a Phase 2 Extension study of GCS-100 in chronic kidney disease. The extension study was initiated at the request of the company's lead investigators, to study long-term safety and efficacy of GCS-100 in patients who completed the initial 12-week Phase 2 study. The Phase 2 Extension study (GCS-100-CS-4003) will enroll CKD patients who completed the 12-week Phase 2 study (GCS-100-CS-4002), including a maximum of 115 patients at 5 sites.

Subjects will be randomly assigned 1:1 to treatment with 1.5 mg/m(2) GCS-100 or 30 mg/m(2) GCS-100. All doses of study drug will be administered intravenously once weekly for up to 8 consecutive weeks with a 4 week follow-up period and then at least once a month for a total of 1 year. The primary objective of the Phase 2 Extension study is to determine the safety and tolerability of extended dosing with GCS-100.

The secondary objective will be to determine the efficacy as measured by eGFR of GCS-100 administered for 8 weeks relative to the effect of 8 weeks of treatment for the same patient on the GCS-100-CS-4002 study including those who were on placebo. This study also provides the opportunity to compare crossover data for individual patients from the initial Phase 2 study and this extension study. The initial 12 week Phase 2 study (GCS-100-CS-4002) enrolled 121 subjects, at least 18 years of age, with Stage 3b or 4 CKD across 6 sites.

In this study, subjects were randomly assigned 1:1:1 to treatment with placebo, 1.5 mg/m(2) GCS-100 or 30 mg/m(2) GCS-100. Randomization was stratified into two groups according to baseline renal function as defined by eGFR values of 15-29 and 30-44 mL/min/1.73m(2), respectively. Once randomized, subjects receive eight consecutive weekly doses of their assigned treatment with a follow-up four weeks after treatment.

Initial data from this study is expected to be available in March 2014. GCS-100 is a complex polysaccharide that has the ability to bind to and block the effects of galectin-3. Galectin-3 is a soluble protein, over-expression of which has been implicated in a number of human diseases including cancer and chronic organ failure. The unique ability of GCS-100 to bind and sequester galectin-3 makes it an ideal candidate to prevent and treat diseases in which galectin-3 plays an important role.