The U.S. Food and Drug Administration has designed the combination of TG-1101 and TGR-1202 an Orphan Drug as a potential treatment for people with chronic lymphocytic leukemia (CLL). The therapy, developed by TG Therapeutics, is currently being evaluated in a Phase 3 clinical trial now enrolling patients.
Orphan Drug status is given by the FDA to therapies intended to treat diseases affecting fewer than 200,000 people in the U.S., and involves financial incentives, among others, that encourage and accelerate their development.
“Receiving orphan drug designation for our proprietary combination of TG-1101 and TGR-1202 provides another layer of exclusivity protection on top of the composition of matter patents,” Michael S. Weiss, executive chairman and chief executive officer of TG Therapeutics, said in a news release. “[W]ith enrollment into our UNITY-CLL Phase 3 trial currently exceeding our expectations, we expect to be able to commence a regulatory filing for the combination in 2018 and having orphan drug designation will provide certain cost saving advantages.”
In that clinical study (NCT02612311), the TG-1101 and TGR-1202 combination is being evaluated both in treatment-naive patients as a first-line therapy and in previously treated CLL patients. The trial plans to enroll some 450 patients at multiple sites across the U.S. and Poland; more information is available on its clinical trials.gov webpage. A Phase 2b trial, called UNITY-DLBCL (NCT02793583), is also testing the combination in people with relapsed of refractory diffuse large B-cell lymphoma (DLBCL). It is recruiting about 200 patients at its 35 U.S. test sites.
TGR-1202, an orally available PI3K delta inhibitor, is also being evaluated in combination with Imbruvica (ibrutinib) in relapsed or refractory DLBCL patients. PI3K is highly expressed in cells of hematopoietic (blood cell) origin, and is believed to be important in the proliferation and survival of B-cell lymphocytes.
TG-1101 (ublituximab), in contrast, is a monoclonal antibody that targets the CD20 protein — found at the surface of most leukemia and lymphoma cells — to induce strong immune responses against these cells. It has shown promise in patients with relapsed and refractory CLL and previously treated mantle cell lymphoma, both alone and in combination with other agents.
TG-1101 is also in early clinical development as a possible treatment for autoimmune diseases, including multiple sclerosis.