The investigational therapy GB2064 reduced fibrosis in the bone marrow of patients with myelofibrosis, according to results of a phase 2A study released by the agent’s manufacturer.
Four of five patients treated with GB2064 (Galecto Inc.) — an inhibitor of lysyl oxidase-like 2 (LOXL2) — for at least 6 months experienced a grade 1 or greater reduction in collagen fibrosis of the bone marrow. All four of those patients showed stable hematologic parameters — such as white blood cell count, hemoglobin and thrombocytes — and stable spleen volume. None required transfusion.
The findings — reported from a planned intermediate assessment of the open-label, single-arm MYLOX-1 trial — suggest GB2064 may affect disease progression and be disease modifying, according to investigators.
“It is wholly unprecedented and very encouraging to observe a reduction in collagen fibrosis in this patient population,” researcher Srdan Verstovsek, MD, PhD, professor in the department of leukemia at The University of Texas MD Anderson Cancer Center and a HemOnc Today Editorial Board member, said in a Galecto-issued press release. “It is exciting to see the first clinical validation of LOXL2 as a fibrosis target. I very much look forward to additional developments from this ongoing study in the near future.”
The ongoing MYLOX-1 trial includes patients with myelofibrosis who are ineligible for, refractory to or intolerant of JAK inhibitor therapy. These patients typically have limited treatment options, poor quality of life and a high risk for mortality.
Sixteen patients in the MYLOX-1 trial have received oral GB2064 dosed at 1,000 mg twice daily. Trial protocol specifies patients receive treatment for up to 9 months, undergoing bone marrow biopsies at baseline and at 3 months, 6 months and 9 months.
Safety and tolerability are the primary endpoints. Secondary endpoints include measurements of bone marrow fibrosis and hematologic parameters.
Eight trial participants discontinued treatment due to disease progression or adverse events.
The most common treatment-related adverse events have been gastrointestinal in nature, which researchers characterized as manageable in most cases with standard therapy.
Investigators reported no serious treatment-related adverse events among the five patients who completed at least 6 months of therapy. The only possibly treatment-related serious event reported in the 16-person trial cohort was a fall.