Treatment with momelotinib leads to clinically relevant symptom reduction in patients with myelofibrosis regardless of whether they have been treated with Janus kinase (JAK) inhibitors, according to a study published in Cancer Medicine.

Myelofibrosis clinical trials usually measure response to treatment as a landmark endpoint of a total symptom score reduction of 50% or more from baseline. However, this provides little information about any symptomatic changes that are clinically relevant.

Read more about the symptoms of myelofibrosis

Here, a team of researchers led by Srdan Verstovsek, MD, PhD, from MD Anderson Cancer Center in Houston, Texas assessed the longitudinal changes in total symptom score from baseline over 24 weeks as well as individual symptom scores to better understand the benefits of treatment in patients with myelofibrosis.

They found that patients treated with momelotinib and ruxolitinib as part of a phase 3 clinical trial called SIMPLIFY-1 had similar overall symptom improvements. The total symptom score difference between the 2 groups of patients was less than 1.5 points for each post-baseline visit. 

In a second trial called SIMPLIFY-2, the improvement in total symptom scores in patients treated with momelotinib was consistent with that seen in the SIMPLIFY-1 trial. However, there was progressive total symptom score deterioration compared to the control patients.

Item-level scores were heterogeneous in both the SIMPLIFY-1 and SIMPLIFY-2 studies. A larger proportion of patients treated with momelotinib showed improvements compared to the control group in the SIMPLIFY-1 trial or had stable disease compared to the control group in the SIMPLIFY-2 study. 

In SIMPLIFY-1, the likelihood of symptom improvement was similar, whereas in SIMPLIFY-2, the likelihood of symptom improvement was higher in patients treated with momelotinib.

“These findings suggest that momelotinib provides clinically relevant symptom benefits in the JAK inhibitor-naïve and JAK inhibitor-exposed settings,” the researchers concluded.


Mesa RA, Hudgens S, Floden L, et al. Symptomatic benefit of momelotinib in patients with myelofibrosis: results from the SIMPLIFY phase III studies. Cancer Med. Published online April 6, 2023. doi:10.1002/cam4.5799