Chronic lymphocytic leukemia (CLL) is a cancer of the immune system. It’s a type of non-Hodgkin lymphoma that starts in the body's infection-fighting white blood cells, called B cells. This cancer produces lots of abnormal white blood cells in the bone marrow and blood that can't fight infection.

Because CLL is a slow-growing cancer, some people won’t need to start treatment for many years. In people whose cancer does spread, treatments can help them achieve long-term periods when there is no sign of cancer in their body. This is called remission. So far, no drug or other therapy has been able to cure CLL.

One challenge is that a small number of cancer cells often remain in the body after treatment. This is called minimal residual disease (MRD). A treatment that can cure CLL will have to wipe out all of the cancer cells and prevent the cancer from ever coming back or relapsing.

New combinations of chemotherapy and immunotherapy have already helped people with CLL live longer in remission. The hope is that one or more of the new drugs in development might provide the cure that researchers and people with CLL have been hoping to achieve.

Before a few years ago, people with CLL had no treatment options beyond chemotherapy. Then, new treatments like immunotherapy and targeted therapy began to change the outlook and dramatically extend survival times for people with this cancer.

Immunotherapy is a treatment that helps your body’s immune system find and kill cancer cells. Researchers have been experimenting with new combinations of chemotherapy and immunotherapy that work better than either treatment alone.

Some of these combinations – like FCR — are helping people live disease-free for much longer than ever before. FCR is a combination of the chemotherapy drugs fludarabine (Fludara) and cyclophosphamide (Cytoxan), plus the monoclonal antibody rituximab (Rituxan).

So far, it seems to work best in young, healthier people who have a mutation in their IGHV gene. In a of 300 people with CLL and the gene mutation, more than half survived for 13 years disease-free on FCR.

CAR T-cell therapy is a special kind of immune therapy that uses your own modified immune cells to fight cancer.

First, immune cells called T cells are collected from your blood. Those T cells are genetically modified in a lab to produce chimeric antigen receptors (CARs) — special receptors that bind to proteins on the surface of cancer cells.

When the modified T cells are placed back into your body, they seek out and destroy cancer cells.

Right now, CAR T-cell therapy is approved for a few other types of non-Hodgkin lymphoma, but not for CLL. This treatment is being studied to see whether it could produce longer remissions or even a cure for CLL.

Targeted drugs like idelalisib (Zydelig), ibrutinib (Imbruvica), and venetoclax (Venclexta) go after substances that help cancer cells grow and survive. Even if these drugs can’t cure the disease, they may help people live much longer in remission.

Allogenic stem cell transplantation is currently the only treatment that offers the possibility of a cure for CLL. With this treatment, you get very high doses of chemotherapy to kill as many cancer cells as possible.

Chemo also destroys the healthy blood-forming cells in your bone marrow. Afterward, you get a transplant of stem cells from a healthy donor to replenish the cells that were destroyed.

The problem with stem cell transplants is they’re risky. The donor cells could attack your healthy cells. This is a serious condition called graft-versus-host disease.

Having a transplant also increases your risk of infection. Also, it doesn’t work for everybody with CLL. Stem cell transplants improve long-term disease-free survival in about 40 percent of people who get them.

As of now, no treatment can cure CLL. The closest thing we have to a cure is a stem cell transplant, which is risky and only helps some people survive longer.

New treatments in development could change the future for people with CLL. Immunotherapies and other new drugs are already extending survival. In the near future, new combinations of drugs may help people live longer.

The hope is that one day, treatments will become so effective that people will be able to stop taking their medicine and live a full, cancer-free life. When that happens, researchers will finally be able to say that they’ve cured CLL.