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FDA Approves Keytruda for Refractory or Relapsed Primary Mediastinal Large B-Cell Lymphoma

The U.S. Food and Drug Administration (FDA) has recently given accelerated approval for Keytruda® (pembrolizumab) to treat adult and pediatric patients with refractory primary mediastinal large B-cell lymphoma (PMBCL) or relapsed PMBCL after using two or more lines of therapy. Keytruda® is not recommended for individuals that require urgent cytoreductive therapy, which used to reduce tumor size.1

The approval was based on the results of the KEYNOTE-170 study, which looked at 53 people with relapsed or refractory PMBCL. The overall response rate at median follow-up was 45%, including an 11% complete response rate and 34% partial response rate. 1

What is Keytruda?

Keytruda® is a monoclonal antibody, which is a type of immunotherapy. Monoclonal antibodies are created in the lab to mimic the antibodies that are produced by the body. They target specific areas of cancer cells to block cancer growth or kill cancer cells.2 Keytruda targets the PD-1 receptor and is the first anti-PD-1 therapy to be approved for treatment of PMBCL.3

Primary mediastinal large B-cell lymphoma (PMBCL)

PMBCL is a subtype of diffuse large B-cell lymphoma, the most common type of non-Hodgkin lymphoma. It is a fast-growing lymphoma that begins in the upper chest behind the breastbone, which is the area called the mediastinum. PMBCL most commonly occurs in young women. Since PMBCL begins in the chest and can form sizeable tumors, common symptoms can include difficulty breathing due to pressure on the windpipe or swelling of the face and neck due to pressure on large veins. PMBCL accounts for about 2-3% of all non-Hodgkin lymphomas.4,5

  1. FDA approves pembrolizumab for treatment of relapsed or refractory PMBCL. U.S. Food & Drug Administration. Available at Accessed 6/14/18.
  2. Immune checkpoint inhibitors to treat cancer. American Cancer Society. Available at Accessed 6/14/18.
  3. FDA approves Keytruda for primary mediastinal large B-cell lymphoma. Healio. Available at. Accessed 6/15/18.
  4. Types of non-Hodgkin lymphoma. American Cancer Society. Available at Accessed 6/14/18.
  5. Mediastinal lymphoma. Medscape. Available at Accessed 6/14/18.