How effective is umbralisib as treatment for patients with relapsed or refractory low-grade lymphoma?

The authors assessed the safety and effectiveness of umbralisib (Ukoniq) in patients with relapsed or refractory (r/r) indolent (low-grade) non-Hodgkin lymphoma (iNHL).  

The study concluded that umbralisib was well tolerated and effective for patients with r/r iNHL.

iNHL is a slow-growing cancer of the lymphatic system. Standard treatments are available for patients with iNHL who have never had treatment before. However, treatment options are limited for those treated patients who relapse (cancer returns) or stop responding (refractory) to standard treatments.

Umbralisib is a targeted therapy that blocks two types of proteins called PI3K and CK1. These proteins help cancer cells to live and grow. By blocking them, umbralisib may kill cancer cells or stop them from growing. In a small study, umbralisib has proven to be effective in patients with r/r cancers of the lymphatic system. However, more data regarding the safety and effectiveness of umbralisib in patients with r/r iNHL is needed.

This study enrolled 208 patients with r/r iNHL. Patients had either marginal zone lymphoma (MZL; 69), follicular lymphoma (FL; 117), or small lymphocytic lymphoma (SLL; 22). All patients were given umbralisib 800 mg once a day. The average follow-up time was 27.7 months.  

The overall response rate was 47.1%. Tumor size reduced in 86.4% of patients. The average time the tumor continues to respond to treatment (duration of response or DOR) was 11.1 months for FL, and 18.3 months for SLL. In the MZL group, patients were still continuing to respond at follow-up.

After 2 years, 50.5% of the MZL group, 18.1% of the FL group, and 31.1% of the SLL group were alive without cancer worsening. 

Medium to severe side-effects were reported in 53.4% of patients. The most common side effects included low levels of white blood cells and diarrhea.

The authors concluded that umbralisib was a safe and effective treatment for patients with r/r iNHL.

This study was supported by TG Therapeutics, the manufacturer of umbralisib. The data is based on patients with different subtypes of r/r iNHL. The number of patients is small. Also, there was no comparison group. This study served as the basis for the FDA approval of umbralisib for the treatment of patients with r/r MZL and FL.