The U.S. Food and Drug Administration (FDA) has approved the medicine Keytruda for the treatment of adult and pediatric patients with refractory primary mediastinal large B-cell lymphoma, that have relapsed after two or more previous lines of therapy.
This approval was granted by accelerated approval regulations, which means that further evidence of the drug’s clinical benefit may be needed for continued approval. The full article can be read here, at Business Wire. For more detailed information about the drug, click here to see the Keytruda prescribing information.
Primary mediastinal large B-cell lymphoma (PMBCL) is cancer that is a form of non-Hodgkin lymphoma. It is caused when the body produces abnormal B-cells, which are a type of white blood cell lymphocyte that is involved in stopping infections. In people who have PMBCL, these lymphocytes accumulate in areas of the body, such as in the lungs or mediastinum. As a result, people can experience symptoms such as coughing, chest pain, swelling (usually in the upper body), breathlessness, or hoarseness. Keytruda has been approved by the FDA for the treatment of refractory PMBCL. Refractory means that the cancer is unresponsive to or resistant to a cancer treatment.
Keytruda, developed by Merck (known as MSD outside the US and Canada), is an anti-PD-1 therapy. It functions by activating T lymphocytes (immune cells) and helping the body’s immune system to identify and fight tumour cells. The FDA’s approval of the drug followed supporting results from a trial called Keynote-170. Fifty-three patients with refractory or relapsed PMBCL took part in the open-label trial. They were treated with 200mg Keytruda at three-week intervals, and the treatment ended after 24 months or when their disease progressed or they reached unacceptable toxicity.
This study found that the overall response rate (tumour reduction rate) was 45%, and 11% of patients had a complete response (absence of detectable cancer). 26% of patients had serious adverse reactions, and 8% stopped using Keytruda following adverse reactions.
