Breakthrough in Myelofibrosis Treatment: Revolutionary Triple-Action Drug ‘Omjjara’ Now Available in Korea, Offering New Hope for Pernicious Anemia Sufferers

Can be used as first-line treatment for patients with anemia regardless of JAK inhibitor treatment history

input 2024.09.25 11:36

input 2024.09.25 11:36correction 2024.09.25 11:38
Views 20

[사진=뉴스원]

A new targeted treatment for myelofibrosis, a severe rare blood cancer, is coming to Korea. Unlike existing drugs that have a single target effect, it is a multi-target drug that blocks all three major signal pathways that cause the disease, and is expected to have a strong therapeutic effect.

On the 25th, global healthcare company GlaxoSmithKline Korea (GSK) announced that its myelofibrosis treatment drug ‘Omzzara (ingredient name: Momelotinib hydrochloride hydrate)’ received approval from the Ministry of Food and Drug Safety for the treatment of myelofibrosis in intermediate-risk or high-risk groups of adults with anemia. The indications for this approval include primary myelofibrosis, post-polycythemia vera myelofibrosis, or post-essential thrombocythemia myelofibrosis.

Omzzara is a drug that blocks three major signaling pathways, including ACVR1 (activin A receptor type 1), as well as JAK1 and JAK2 proteins that were blocked by existing treatments. The recommended dose is 200 mg orally once a day, and can be taken with or without meals.

Myelofibrosis is a rare blood cancer that causes symptoms such as anemia, thrombocytopenia, and spleen and liver enlargement as bone marrow fibrosis progresses. It occurs in 1 out of 100,000 people worldwide, and in Korea, approximately 2,292 patients were confirmed to have received hospitalization and outpatient treatment as of 2023. In particular, patients with anemia symptoms have a poor treatment prognosis, but the problem is that most patients experience anemia.

Studies have shown that 87% of patients with myelofibrosis are anemic at the time of referral, and another study found that 46% of patients still required blood transfusions more than a year after diagnosis. In general, the occurrence of anemia in patients with myelofibrosis increases the risk of death by two-fold compared to other prognostic factors such as age, leukocytosis, and systemic symptoms.

Through the global phase 3 clinical trials, the SIMPLIFY-1 study and the MOMENTUM study, Omzzara confirmed its clinical efficacy and safety profile in treating major symptoms such as improving splenomegaly in adult myelofibrosis patients and reducing the dependency on blood transfusions in anemia patients. This domestic approval was also based on the results of the two clinical trials.

First, the SIMPLIFY-1 study directly compared Omzara with ‘ruxolitinib’ in 432 adult patients with myelofibrosis who had not previously received JAK inhibitor treatment, and a post-hoc analysis was conducted in the subgroup with anemia. As a result, Omzara confirmed non-inferiority to ruxolitinib in the primary efficacy endpoint, spleen volume response (35% or more decrease) at 24 weeks of treatment, and did not show non-inferiority in the total symptom improvement score. As a result of checking the transfusion independence rate in each patient group, the transfusion independence rate of patients in the Omzara group was 66.5%, and in the ruxolitinib group was 49.3%, confirming that transfusion dependency was significantly lower in the Omzara group.

Another approved clinical trial, the MOMENTUM study, compared the efficacy and safety of Omzara versus danazol in 195 adults with symptomatic myelofibrosis who had previously received a JAK inhibitor and had anemia. All patients had previously received ruxolitinib, and 4.6% had previously received fedratinib. The co-primary efficacy endpoints were the proportion of patients with a ≥ 50% reduction in the Total Symptom Score (TSS) at Week 24 and transfusion independence. Key secondary endpoints included spleen volume response.

As a result of the study, the proportion of patients in the Omzara group whose TSS was reduced by more than 50% was 25% (32 out of 130 patients), which was a statistically significant improvement compared to 9% (6 out of 65 patients) in the Danazol group. In addition, the proportion of patients who maintained transfusion independence with a hemoglobin level of 8 g/dL or higher for the first 12 weeks after starting treatment was confirmed to be higher in the Omzara group. Furthermore, in terms of spleen volume response (more than 35% decrease in spleen volume) at 24 weeks of treatment, the Omzara group showed a difference of about 7 times (22%, 3% in the Danazol group), confirming the effect of symptom improvement.

Commonly reported non-hematologic adverse reactions in patients administered Omzzara included diarrhea (22.8%) and nausea (16.7%), and the most common grade 3 or higher adverse reaction was thrombocytopenia (10.7%).

“Myelofibrosis is a disease characterized by dysregulated JAK signaling, increased inflammation, and overactivation of ACVR1. Despite the development of treatments, there has been an ongoing medical need related to anemia,” explained Yang Yoo-jin, executive director and head of GSK Korea’s HIV/Oncology business unit.

In doing so, he said, “By blocking all three major signaling pathways that cause myelofibrosis, Omjja showed excellent therapeutic effects not only in improving major symptoms but also in improving major indicators related to anemia that impede the long-term treatment prognosis and survival of patients,” and expected that “it will be able to present a new turning point in the domestic treatment environment.”

Meanwhile, Omjja received its first approval from the U.S. Food and Drug Administration (FDA) in September 2023, and is currently approved in the U.S., Europe, and Japan.

Copyright ⓒ Honest knowledge for health. kormedi.com / Unauthorized reproduction and redistribution, AI learning and use prohibited