Phase 2 Trial Shows Fibrosis Reduction in Some With Myelofibrosis

A phase 2a trial of novel monotherapy GB2064 demonstrated a reduction of fibrosis in the bone marrow, which helps slow down cancer progression, in patients with myelofibrosis who had been previously treated with Jakafi (ruxolitinib), according to a news release.

The MYLOX-1 trial administered doses of GB2064 to 18 total patients with myelofibrosis who previously received Jakafi, a type of janus kinase inhibitor. Eight of the 18 patients were unable to respond to treatment and three patients were intolerant to treatment with Jakafi.

The news release stated that six out of 10 evaluable patients had a one or more-grade reduction in collagen fibrosis (growth of fibrous tissue) of the bone marrow after receiving the novel GB2064 monotherapy for six months.

In the six patients who had a fibrosis reduction, the researchers reported that the levels of hemoglobin, platelets and white blood cell count were stable.

After six months of treatment, the news release noted, one patient showed a 35% or more reduction in spleen volume. Researchers found that two patients were able to reduce their amount of symptoms by more than 50%, although one other patient experienced an anemia response.

The researchers stated that four of the six patients who had a fibrosis reduction entered the extension phase of the trial, as they demonstrated a clinical benefit after receiving GB2064. Notably, one patient exceeded the six months of treatment and received treatment for more than 30 months, according to the news release.

The trial’s researchers determined that treatment with GB2064 could potentially have benefits for this patient population, particularly regarding disease progression, and also noted that it could be disease-modifying.

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“It is exciting and encouraging to see that the data from the MYLOX-1 trial affirms the safety and effectiveness of LOXL-2 inhibition in the challenging landscape of myelofibrosis,” Claire Harrison, clinical director of Guy’s and St Thomas’ NHS Foundation Trust and chair of the safety review committee for the MYLOX-1 trial, said in the news release. “I am especially intrigued by the unique observed improvements in bone marrow collagen fibrosis, showcasing the targeted impact on a crucial aspect of this relentless disease.”

In terms of safety, the news release stated that treatment with GB2064 in the trial demonstrated a “generally acceptable tolerability profile.” The researchers established that eight patients completed treatment in the core phase of the trial, but 10 patients had to discontinue the treatment after experiencing side effects or disease progression.

The most common treatment-related side effects patients in the trial experienced were gastrointestinal-related, which were manageable in most of the patients with standard therapy, according to the news release. Researchers reported that one patient had fallen as a possible result of the GB2064 treatment, noting it as the only serious side effect.

“We believe that the topline results from the MYLOX-1 trial reaffirm the anti-fibrotic activity observed in the intermediate assessment of the trial announced in September 2022,” Dr. Hans Schambye, president and chief executive officer of Galecto, the manufacturer of GB2064, said in the release.

“We are very excited with the proof of principle achieved with GB2064, showcasing its strong anti-fibrotic impact in a very challenging patient population,” Schambye continued. “The encouraging topline results from the MYLOX-1 trial reinforce our confidence in GB2064's potential as a transformative therapy for various cancers and a range of fibrotic diseases, but we will not make any decisions relating to funding additional trials with GB2064 until we complete our previously announced strategic alternative process.”

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