Umbralisib can revitalize ruxolitinib in MF

Efficacy

Two patients could not be assessed for efficacy, and 8 had stable disease on umbralisib and ruxolitinib.

The combination produced clinical improvement—reduction in spleen volume, increase in hemoglobin, and improvement in MF-related symptoms—in 11 patients (48%).

And 2 patients (9%) achieved a CR. Dr Moyo said there were “few commonalities” between these 2 patients.

Both had intermediate-1-risk disease as well as persistent or progressive MF-related symptoms and thrombocytosis at baseline. However, 1 patient had post-ET MF, and 1 had post-PV MF.

The post-ET MF patient had an MPL driver mutation. She received ruxolitinib at 20 mg twice daily and umbralisib at 400 mg daily. The patient achieved a CR at cycle 15 and remained on study 2 years before proceeding to transplant. The patient is now about 1 year from her transplant with no evidence of disease.

The post-PV patient had a JAK2 V617F driver mutation. She received ruxolitinib at 15 mg twice daily and umbralisib at 600 mg daily. The patient achieved a CR at cycle 5 and remains on study, currently receiving cycle 12 of treatment.

Dr Moyo said these results suggest “the addition of umbralisib to ruxolitinib can augment or resurrect a response in MF patients who have had suboptimal or lost response to ruxolitinib alone, and this treatment combination warrants further investigation.”