S*BIO to initiate global phase 3 clinical trials of its novel JAK2 inhibitor

S*BIO Pte Ltd announced plans to initiate a global phase 3 clinical program of its novel JAK2 inhibitor pacritinib (SB1518), in the first half of 2012 to further demonstrate its activity and tolerability for the treatment of myelofibrosis (MF). The company is actively exploring partnering opportunities for the advancement of its leading JAK2 program.

“Data from phase 1 and 2 clinical studies have demonstrated that pacritinib is well tolerated and active in the treatment of myelofibrosis, an orphan disease with a high unmet medical need,” said Tamar Howson, interim CEO and board member of S*BIO. “We are moving forward with an aggressive and focused development plan with global phase 3 trials for pacritinib to further demonstrate its clinical benefits in MF patients and to maximise the value of our JAK2 program. We are currently in the process of identifying a suitable partner for the phase 3 studies and pacritinib’s subsequent commercialization.”

The primary objective of the double-blind, placebo-controlled phase 3 studies is to compare the efficacy of pacritinib versus placebo in achieving clinically significant reduction in spleen size in MF patients with splenomegaly. Secondary outcomes of both studies include patient-reported change in the most bothersome symptom identified at baseline, duration of response, as well as overall survival. The trials will enrol up to 500 MF patients.

In phase 2 studies, treatment with pacritinib resulted in sustained reduction in MF-associated splenomegaly with no evidence of myelosuppression and no exacerbation of cytopenias. Pacritinib is a small molecule JAK2-selective kinase inhibitor that demonstrated high potency in preclinical models against both the wild type JAK2 kinase and the JAK2 kinase with the V617F mutation. The V617F mutation is found in high frequency in myeloproliferative disorders such as MF. More than 50 percent of patients with MF possess the JAK2 mutation.