Atezolizumab Clinical Trials

Atezolizumab (Tecentriq) is an immunotherapy drug that is currently only available to mesothelioma patients through clinical trials. Right now it is only approved for certain patients with advanced non-small cell lung cancer or bladder cancer. It is being tested in clinical trials for various types of cancer, including mesothelioma. If you are interested in getting involved in a trial with atezolizumab, talk to your specialists to find out if you qualify.

What is Atezolizumab?

Atezolizumab is the generic name for a drug with the brand name Tecentriq. It is an immunotherapy drug made by the biotech company Genentech. Atezolizumab was first approved by the U.S. Food and Drug Administration (FDA) to treat advanced and metastatic urothelial carcinoma, also known as bladder cancer.

The FDA gave accelerated approval of the drug for special cases of bladder cancer. These include patients who cannot be given platinum-based chemotherapy drugs or who were given chemotherapy but experienced progression of the tumors. This kind of approval from the FDA requires that clinical trials keep going and can be rescinded if results don’t show the expected benefits.

More recently the FDA approved atezolizumab for patients with non-small cell lung cancer in similar situations. Those who see their disease progress after treatment with platinum chemotherapy drugs can be given atezolizumab. It’s given to patients with this type of lung cancer along with carboplatin, paclitaxel, and another immunotherapy drug bevacizumab.

How Atezolizumab Works

Atezolizumab is an antibody that has been designed to target a specific protein on cancer cells. Immune system cells, known as T-cells, need to be able to recognize pathogens and distinguish them from healthy cells. Normal cells in the body have proteins on their surfaces known as immune checkpoints. When a T-cell binds to one of these it recognizes it as normal and not a threat.

Cancer cells have evolved to trick the immune system into thinking they are normal, healthy cells. They express checkpoint proteins that signal to the immune cells the same way healthy cells do. Different types of tumors and individuals with cancer have cancer cells that may express different types of these checkpoint proteins.

Atezolizumab was developed to inhibit the interaction between immune T-cells and a specific checkpoint protein on cancer cells known as PD-L1. It works by binding to PD-L1 and preventing T-cells from binding there. In this way the drug unmasks the cancer cells and the immune system is able to recognize they are unhealthy and should be targets for destruction.

Atezolizumab is specific to tumors whose cells have a lot of PD-L1. Some types of cancers express more of this protein than others, like bladder cancer. But there are also individual differences, so one person may have a cancer with more PD-L1 and may benefit from this treatment more than another.

Clinical Trials for Mesothelioma

Mesothelioma tumors often overexpress PD-L1, making the cancer a good candidate for trials using atezolizumab. One clinical trial that is currently ongoing is testing the 18-week non-progression rate in participants being given atezolizumab. This means that the researchers are determining how many participants see no progression, or growth, in their tumors after 18 weeks with the novel treatment. No progression is considered a success.

The trial is currently in phase II with 477 patients participating. The researchers have focused on patients with prostate cancer or pleural mesothelioma who have failed to get results from other types of treatment.

Another trial that is more recent and still in phase I is focusing only on pleural mesothelioma and is accepting patients diagnosed with the cancer in stages I, II, or III. The trial is using atezolizumab along with chemotherapy drugs cisplatin and pemetrexed. Patients are also undergoing surgery as part of treatment and may or may not be receiving radiation therapy. The hope is that the new drug along with chemotherapy drugs will shrink tumors, making surgery easier and more successful.

Potential Side Effects

Immunotherapy drugs typically cause milder and fewer side effects than chemotherapy because they are more targeted, but they can still have some undesirable consequences. The most common side effects and adverse events of atezolizumab are recorded for the types of cancer it is approved to treat. The potential problems that could arise in mesothelioma patients are not as well understood, but they could be similar.

For bladder cancer the most common side effects reported are fatigue, constipation, nausea, loss of appetite, diarrhea, fever, and urinary tract infections. Patients taking atezolizumab for non-small cell lung cancer may experience fatigue, loss of appetite, cough, or difficulty breathing.

Atezolizumab is not yet approved for treatment in patients with mesothelioma, but it is accessible through clinical trials. Researchers are hoping that it can help shrink tumors or slow the growth of cancer in mesothelioma. Results are not yet available and trials are ongoing. To find out if you qualify for a clinical trial, talk to your medical team.