The US Food and Drug Administration (FDA) has approved an antibody-drug conjugate to treat people with diffuse large B-cell lymphoma (DLBCL), the most common type of non-Hodgkin lymphoma in the US. The new drug, Polivy (polatuzumab vedotin-piiq), is approved to be used along with the chemotherapy drug bendamustine and a rituximab product (a combination known as “BR”) to treat adults whose DLBCL has gotten worse or come back after at least 2 previous therapies.
An antibody-drug conjugate is a targeted drug combined with chemotherapy. The targeted drug finds the cancer cell and then delivers the chemo to destroy it. In this case, Polivy attaches to a specific protein found on B cells in people with lymphoma, then releases its chemotherapy into those cells to kill the cancer.
“Antibody-drug conjugates are an emerging class of targeted immunotherapies for cancer. This type of therapy, unlike traditional chemotherapy, is intended to target specific cells,” said Richard Pazdur, MD, director of the FDA’s Oncology Center of Excellence and acting director of the Office of Hematology and Oncology Products, Center for Drug Evaluation and Research, in a statement.
Polivy was approved under the FDA’s accelerated approval program for drugs that show promise against a serious disease. The company that makes the drug must submit additional clinical information after approval, to demonstrate its benefit.
The FDA granted the approval based on complete response rates observed in a randomized controlled clinical trial. Complete response means the cancer can no longer be detected in a person’s body.
The trial involved 80 people with DLBCL that had gotten worse or come back after an average of 2 previous therapies. They were randomly assigned to receive either Polivy with BR or BR alone. At the end of treatment, 40% of the Polivy+BR group had a complete response compared with 18% of the BR alone group. Of the 25 patients treated with Polivy+BR who saw a complete or partial response, 16 (64%) had a response lasting at least 6 months and 12 (48%) had a response lasting at least 1 year.
The most common side effects of Polivy plus BR include low blood counts, peripheral neuropathy (nerve damage), fatigue, diarrhea, fever, low appetite, and pneumonia.
Health care providers should watch patients closely for infusion-related reactions, low blood counts serious infections, tumor lysis syndrome (a complication from many tumor cells being killed off at the same time), liver damage, and progressive multifocal leukoencephalopathy (a fatal or life-threatening infection of the brain). Women who are pregnant or breastfeeding should not take Polivy because it may cause harm to a developing fetus or newborn baby. Women should not become pregnant while taking Polivy, and for 3 months after the last dose.
Polivy is marketed by Genentech.