What is a Complete Response Letter or CRL?

What is a Complete Response Letter or CRL?

A sponsor of a drug receives a CRL or Complete Response Letter from the FDA when the FDA needs to tell the sponsor that the NDA has been reviewed and cannot be accepted in its current form. The CRL replaces the old FDA “approvable” and “non approvable” letter formats. The CRL essentially tells the sponsor what to do to make the NDA acceptable to the FDA. It might discuss specific issues with the NDA, and sometimes recommend actions necessary for approval.

Sometimes, the CRL is easily resolvable, as is often the case with manufacturing or production issues, or when no new trials are asked for, but simple responses from existing data. Sometimes, however, the CRL may actually require a new trial, as we have seen recently in the case of Cempra's solithromycin.

Such a new trial is often difficult for a pre-approval stage company to perform, effectively amounting to a rejection of the drug. As investors, we would like to see the text of such CRLs from the FDA so we can form our own conclusions. However, CRLs are not made public by the FDA, but privately communicated to the sponsor who is free to disclose as much or as little of it as it wants.

What is a monoclonal antibody?

A monoclonal antibody or mAb is an antibody produced in the laboratory from a single ancestral plasma cell

What Is Non-Hodgkin Lymphoma?

Non-Hodgkin lymphoma (also known as non-Hodgkin’s lymphoma or NHL) is a cancer of the lymphocytes, a type of white blood cells and an important part of the immune system.

What is INI1 and SMARCA4?

INI1 and SMARCA4 are subunits of SWI/SNF, a chromatin modifying protein complex, which opposes the activity of PRC2, the complex within which EZH2 resides.