OB756 in ET: Results from a phase II trial

Results from a phase II, open-label, multicenter trial evaluating OB756, a novel, oral selective Janus kinase (JAK) 2 inhibitor, in patients with essential thrombocythemia (ET) who were resistant to or intolerant of hydroxyurea, or intolerant of interferon (N = 50), were recently published in Cancer by Huang et al.

Key data: At Week 24, the complete hematologic response rate was 22%. Among evaluable patients at Week 24 (n = 38), the hematologic response rate reached 65.6% and 94.7% experienced spleen volume reduction. Most treatment-related adverse events were Grade 1–2, with Grade ≥3 hematologic events including anemia (10%) and neutropenia (6%). The incidence of Grade ≥3 infections was 16%.

Key learning: OB756, a novel JAK2 inhibitor, demonstrated acceptable efficacy and was well-tolerated in patients with ET who are resistant to or intolerant of hydroxyurea, or intolerant of interferon, offering a new therapeutic option for this patient population.