Bispecific Antibodies Deliver One-Two Punch to Non-Hodgkin Lymphoma

Antibodies are proteins that find and stick to another type of protein called an antigen on the surface of germs or abnormal cells. Rituxan is a monoclonal antibody. It’s a man-made version of the antibodies your immune system uses as scouts to circulate throughout your body and find foreign invaders. Rituxan sticks to a protein called CD20 on the surface of cancer cells. Then it helps your immune system destroy those cells.

Bispecific therapies are different, in that they can bind to two antigens at once. One arm of the treatment binds to the cancer cell and attacks it directly. Meanwhile, the other arm attaches to a “killer” immune cell called a T-cell, and pulls it toward the lymphoma cell. Ultimately, the cancer gets attacked on two fronts.

Bispecific antibody treatment has some advantages over chimeric antigen receptor (CAR) T-cell therapy. In CAR T-cell therapy, doctors re-engineer a person’s T-cells in a lab to help these cells find and attack the cancer. It’s a highly personalized treatment, which makes it both time consuming and expensive.

However, it also has some disadvantages compared to CAR T-cell therapy. For example, CAR T-cell therapy is a one-time treatment. You may need to be on the bispecific antibody treatment for a longer period of time until your disease no longer responds to it. Currently, only CAR T-cell therapy is FDA-approved for certain types of non-Hodgkin lymphoma. Bispecific antibodies are still under investigation in clinical trials.

Promising, But Not Ready for Primetime

“Right now, bispecific antibodies are not a standard of care therapy. They’re only available in investigational trials,” says Dr. Ahmed. Only certain people qualify to take part in these studies.

It may be worth asking your doctor about enrolling in a clinical trial of bispecific antibodies if you’ve already had a stem cell transplant and CAR T-cell therapy, but your cancer has continued to grow. Entering into a study might also be a possibility if you weren’t a good candidate for a transplant or CAR T-cell therapy, and you’ve already tried a few other treatments without success.

Clinical trials are not only evaluating how well bispecific antibodies work on their own, but also how they might work when combined with other cancer drugs — both ones that are currently on the market, and some that are still under investigation. “We are going to be moving forward in combination and seeing if we can improve the outcome by adding different agents together,” Dr. Ahmed tells SurvivorNet.

Can They Cause Side Effects?

Any drug you take to treat cancer can cause side effects, and bispecific antibodies are no exception. The side effects they can cause are similar to those of CAR T-cell therapy, including fever, chills, headache, nausea, vomiting, low blood cell counts, and diarrhea. However, they’re “much more mild,” Dr. Ahmed says.

Bispecific antibodies can also cause a more serious problem called cytokine release syndrome, or CRS. Cytokines are cells that send out signals to help coordinate the immune response. In CRS, these cells become overactivated by the immune therapy, leading to symptoms like headache, rash, fast heartbeat, and low blood pressure. In most people, CRS is mild, but it can sometimes become more serious.

Before you start taking bispecific antibodies or any other new treatment, your doctor should explain to you what side effects it can cause, and how to manage any problems that do arise.

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