FDA Grants Orphan Drug Designation to Cellectar’s CLR 131 for the Sixth Time


The biopharmaceutical company Cellectar Biosciences recently announced that the FDA granted its lead phospholipid drug conjugate, CLR 131, Orphan Drug Designation(ODD) for treatment of lymphoplasmacytic lymphoma.

ODD is granted by the FDA for treatments of disorders affecting less than two hundred thousand people living in the United States. ODD grants market exclusivity to the product for seven years if it is approved. There are other benefits including tax credits and grants for specific research.

CLR 131 Designations

To date, CLR 131 received the following designations:

What is  Lymphoplasmacytic Lymphoma?

Lymphoplasmacytic lymphoma (LPL), a form of non-Hodgkin’s lymphoma, is a slowly progressing cancer that is found mostly in older adults.

The body’s lymph system represents a portion of the immune system which fights infections. When lymphoma (cancer) strikes, the white blood cells (either T or B lymphocytes) reproduce uncontrollably due to mutations (cell abnormalities).

Typically, in LPL, the B lymphocytes multiply in the bone marrow, displacing normal blood cells. The immune system is compromised and the results may be a low white blood cell count (neutropenia), anemia, or low blood platelets (thrombocytopenia).

The CLOVER I Phase II Study

CLR 131 is being tested in Cellectar’s ongoing clinical study called CLOVER1. The subjects are patients with various select B-cell malignancies including lymphoplasmacytic lymphoma (LPL) who have either relapsed or who do not respond to treatment (refractory).

The CLOVER1 study is being conducted in ten cancer centers throughout the U.S. The cancers being studied are:

A total of eighty patients are to be enrolled. The primary endpoint will be the expectation of an improvement in at least one symptom that is a direct result of the treatment.

Additional endpoints include:

  • The length of time the patients live without any progression of the disease
  • The length of time for the patients’ initial response to treatment
  • Overall survival. This is a percentage of people alive after a specific period of time (usually measured in years)
  • Other endpoints may be included as deemed appropriate.

The National Cancer Institute awarded Cellectar over $2 million to assist in funding the trial.

About CLR 131

CLR 131 is a small molecule-based phospholipid-ether drug conjugate (PDC) that is designed for delivery of radiation to cancer cells. As a “targeted” drug, its exposure to normal cells is limited, while at the same time its potency is increased, even at lower concentrations.

CLR 131 is also being studied in two Phase I trials testing the drug for dose escalation. One study involves multiple myeloma patients and the second trial evaluates the drug’s potency in lymphoma and pediatric solid tumors.

The Company

Cellectar Biosciences’ primary objective is to develop drugs that efficiently and safely zero in on cancer cells with less off-targeting. Cellectar has exhibited the potential to discover and develop next generation cancer-targeting therapies.

Cellectar’s President and CEO confirmed that the company is focused on the development of therapies to treat rare cancers that have few treatment options.


Rose Duesterwald

Rose Duesterwald

Rose became acquainted with Patient Worthy after her husband was diagnosed with Acute Myeloid Leukemia (AML) six years ago. During this period of partial remission, Rose researched investigational drugs to be prepared in the event of a relapse. Her husband died February 12, 2021 with a rare and unexplained occurrence of liver cancer possibly unrelated to AML.

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