FDA Grants Fast Track Designation to Diffuse Large B-Cell Lymphoma Drug Candidate

According to a press release from the New Jersey-based biotechnology company Cellectar Biosciences, the Food and Drug Administration (FDA) has granted “Fast Track” designation to the Company’s experimental diffuse large B-cell lymphoma drug, CLR 131.

Fast track designation, like many of the other designations distributed by the FDA, is designed to expedite the development and review of experimental drugs that fulfill “unmet medical need.”

About Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common form of non-Hodgkin’s lymphoma (NHL) in the world. Estimates vary, but DLBCL accounts for between nearly one-fourth and one-third of all newly diagnosed cases of NHL.

Non-Hodgkin’s lymphomas are cancers that originate in the lymphocytes of your lymphatic system. Lymphocytes are a type of white blood cell that plays an important part in your immune response, and there are two subtypes — B and T lymphocytes. T lymphocytes attack and help destroy tumors and other hostile bodies the immune system targets. B lymphocytes, on the other hand, produce antibodies.

NHL cases are classified according to the lymphoma’s origin — B-cell and T-cell lymphomas, as logic would dictate. These types are further subcategorized into numerous unique conditions, such as diffuse large B-cell lymphoma.

DLBCL is the most common type of NHL in the world, and unfortunately, also one of the most aggressive. It grows quickly, especially in those it most commonly affects — patients over the age of 60. Although it originates in the lymphatic system, DLBCL can occur throughout the body at “extranodal” sites including the brain, testes, skin, and pretty much any other organ you can imagine.

Despite the aggression and prevalence of DLBCL, the prognosis for patients is highly dependent on the particular DLBCL in question (yes — there are subtypes of this, too) and how far it has progressed. Some estimates suggest as many as half of all DLBCL cases are curable.

Chemotherapy is the primary method of treatment, though radiation or stem cell therapies may also be employed in certain cases. Typically, chemotherapy for DLBCL involves the administration of four-to-five anti-cancer drugs for up to four months. However, purpose-made drug is still lacking.

About CLR 131 and Fast Track Designation

CLR 131 is a small-molecule radiotherapeutic drug and Phospholipid Drug Conjugate (PDC) – a class of drug that is able to target cancer cells more selectively by zeroing in on unique molecular targets that are found in tumors.

In theory, CLR 131 delivers small amounts of the radioactive isotope iodine-131 to tumor cells only. Like most anti-cancer drugs, the radioactive isotope is cytotoxic — but the “highly selective uptake and retention” of PDCs suggests that, unlike other cancer drugs, CLR 131 may not damage otherwise healthy cells.

A phase II study of CLR 131 is currently recruiting up to 80 DLBCL patients at 10 cancer centers around the country. Participants will receive one of two possible doses of CLR 131, and their responses will be evaluated. Phase II trials are the first step in clinical testing concerned with establishing efficacy — earlier trials exist chiefly to confirm that the drug being studied is itself not a risk to human health. Though early trials of CLR 131 have shown to be promising, the drug doubtlessly has a long clinical road ahead of it.

Even with fast track designation, which exists to accelerate the development and review process, it could be years before CLR 131 is approved for marketing — if ever.


There are numerous FDA designations that drugs and drug manufacturers can earn to speed up the review process of their products. How should we determine what conditions gain government support? Share your thoughts with Patient Worthy!

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