For more than three decades, care for small-cell lung cancer (SCLC) remained mostly the same. That’s changing now -- doctors have a new option called immunotherapy. This line of treatment uses your body’s own immune system to fight cancer.
Immunotherapy for SCLC is still in the early stages. Scientists are studying the medicines. But doctors are prescribing a few of them to patients who stop responding to other treatments.
What Is Immunotherapy?
The immune system is your body’s defense against harmful substances. It attacks foreign particles, like germs and viruses. But cancer can confuse your body. As cells change and grow out of control, your immune system may not think them as a threat.
Scientists have developed drugs to help your immune system target and destroy cancerous cells. They include:
Immune checkpoint inhibitors: Some immune cells have proteins that act as off switches. These “checkpoints” prevent them from killing cancer cells. Immune checkpoint inhibitors target these proteins and allow immune cells to attack the cancer. These types of drugs are the most promising for SCLC.
Monoclonal antibodies: These man-made immune system proteins can attack certain parts of cancer cells. They’re also used as checkpoint inhibitors.
Cancer vaccines: These substances kick-start an immune system response. They can prevent or treat certain cancers. Scientists are beginning to study vaccines for SCLC.
Which Drugs Treat SCLC?
Right now, there aren’t any FDA-approved immunotherapy drugs for SCLC. To receive this green light, drugs have to go through four phases of clinical trials. These studies decide if a treatment is safe and if it works.
Most immunotherapy drugs for SCLC are in the first or second phase. That means researchers still need to do trials on larger groups for longer periods of time. That’s how they figure out what the long-term side effects of the drugs might be.
Doctors can still prescribe certain immunotherapies for SCLC. This practice is called off-label use. You might also get one if you join a clinical trial for a treatment.
The following immunotherapies for SCLC are in different stages of development:
Nivolumab (Opdivo): You might take this checkpoint inhibitor on its own, or in combination with another drug called ipilimumab (Yervoy). These drugs can shrink tumors and help people with SCLC live longer. The National Comprehensive Cancer Network, a nonprofit organization of 27 cancer centers, recognizes nivolumab and ipilimumab as an SCLC treatment.
Pembrolizumab (Keytruda): This checkpoint inhibitor works on a certain type of SCLC called PD-L1-positive. Your doctor will test to see if you fall into this group. You can get the drug through a clinical trial. Or your doctor can request it from the maker. This “expanded access program” allows people with serious diseases get the treatment.
Rovalpituzumab tesirine: This treatment uses cancer drugs attached to a protein in your immune cells that targets specific proteins on cancer cells. Once they’re inside the cancer cell, they release the medication and destroy it. This drug is in phase II of clinical trials. You’ll have to join a trial to receive the drug.
Tarextumab: Known as a monoclonal antibody, it works to prevent certain cancer molecules from talking to each other. This may keep cancerous cells from spreading. Tarextumab is in phase II of clinical trials. To receive it, you’ll need to enroll in a trial.
When Do You Get Immunotherapy?
Depending on how much your cancer has spread, your cancer doctor will usually recommend treatment with surgery, chemotherapy, or radiation. But SCLC is an aggressive disease that grows quickly. It often becomes resistant to the chemotherapy drugs. Most of the time, the cancer returns.
That’s when it’s time to try immunotherapy. Because scientists are still studying the drugs, doctors are careful about when to prescribe them. They can cause serious side effects, like inflammation of the organs. Your doctor will weigh the pros and cons. Most people get immunotherapy after two or more rounds of chemotherapy.
Many of these drugs target certain proteins on cancer cells. Your doctor may test your for high levels of these proteins. This can help her figure out which treatment is best for you.
How Do You Get the Treatment?
You go to your doctor’s office, a clinic, or the outpatient unit of a hospital. An IV will deliver the immunotherapy into your vein. The process usually takes around an hour. Depending on the drug, you’ll receive treatment every few weeks.
Your doctor will decide how long you’ll get this medication. Usually the goal of is to prevent the cancer from getting worse instead of curing the disease.