In the United States, Orphan Drug designation is granted to drugs or biologics intending to treat, prevent, or diagnose rare diseases or conditions. A rare condition is one affecting fewer than 200,000 Americans. Drug developers also benefit from this status. With Orphan Drug designation comes fee waivers, tax credits, and seven years of market exclusivity upon drug approval. According to CGT Live, the FDA granted Orphan Drug designation to MB-106, a CAR T-cell therapy for Waldenstrom macroglobulinemia, at the end of June 2022.
MB-106 is a 3rd generation, CD20-targeted autologous CAR T-cell therapy. It is currently being evaluated for a range of indications, such as diffuse large B-cell lymphoma (DLBCL), chronic lymphocytic leukemia (CLL), and Waldenstrom macroglobulinemia. Study data so far has found MB-106 to be safe, effectively, and well-tolerated. In one study, researchers saw a 96% overall response rate, with a 100% complete response for Waldenstrom macroglobulinemia.
Currently, researchers are evaluating MB-106 in a Phase 1/2 study with another Phase 1/2 study in the works.
About Waldenstrom Macroglobulinemia (WM)
Waldenstrom macroglobulinemia (WM) is a rare form of lymphoma which begins in B lymphocytes, a type of white blood cell. Normally, B lymphocytes help play a role in immune response and protection. However, in Waldenstrom macroglobulinemia, the cancerous cells overproduce abnormal protein antibodies called immunoglobulin M (IgM). The cancer cells accumulate, crowding out healthy red blood cells and leading to hyperviscous (overly thick) blood. This cancer is 2x more common in males than females. It also more heavily affects Caucasians and those older in age compared to other groups. Symptoms may not appear until later stages. When symptoms do appear, they can (but do not always) include:
- Enlarged lymph nodes of the spleen
- Unintended weight loss
- Raised pink or flesh-colored skin lesions
- Easy bruising and bleeding
- Headaches and/or dizziness
- Poor concentration
- Blurred vision
- Thrombocytopenia (low platelet counts)
- Neutropenia (low white blood cell counts)
- Frequent or recurrent infections
- Anemia (low red blood cell count)
- Fatigue and overall weakness
- Shortness of breath
- Diarrhea
- Abdominal swelling
- Bleeding from the nose or gums
