TG Therapeutics (NASDAQ:TGTX) received the FDA’s orphan drug designation for its phosphoinositide-3-kinase delta inhibitor, umbralisib, for the treatment of patients with marginal zone lymphoma (MZL).
MZL is a slow-growing, B-cell non-Hodgkin lymphoma that originates in the marginal zone of lymphoid tissue. Umbralisib’s orphan drug designation applies to all three types of MZL: nodal, extranodal, and splenic.
TG Therapeutics is currently evaluating the safety and efficacy of umbralisib in a Phase 2b trial in MZL patients who have previously received at least one anti-CD20 regimen. The trial’s primary endpoint is overall response rate (ORR), and secondary endpoints are safety, duration of response, and progression-free survival.
“Receiving orphan drug designation for umbralisib in patients with MZL is another important milestone in our commitment to developing novel treatment options for patients with B-cell malignancies, including orphan diseases such as MZL,” Michael Weiss, TG Therapeutics’ executive chairman and CEO, said in a statement.
Interim results from the Phase 2b study have been positive, with the first 42 patients enrolled demonstrating a 52% ORR. TG Therapeutics expects to present final data later in 2019, with the potential to file for accelerated approval by year-end.
