Mesothelioma specialists have become increasingly optimistic about immunotherapy treatments, and the one that seems to be taking center stage is tremelimumab. Doctors recently released results from a Phase 2 study of the drug, and the results were promising. Tremelimumab is only available through clinical trials.
Doctors and scientists have studied the effects of tremelimumab for years, and they have been particularly hopeful about it as a treatment for advanced mesothelioma patients. Dr. Lee Krug, a specialist at Memorial Sloan-Kettering, has long promoted further research into these types of drugs because of their potential benefit.
“Immunotherapy drugs such as tremelimumab have garnered tremendous excitement in the oncology field due to their promising results in numerous cancers such as melanoma skin cancer and lung cancer,” Dr. Krug said to the Meso Foundation in 2014.
How Does Tremelimumab Work?
Tremelimumab is a type of immunotherapy treatment known as a monoclonal antibody. This antibody is created in a lab by cloning other antibodies. In the lab, the antibodies are designed to recognize specific proteins on the surface of certain cells; in this case, mesothelioma cells. Once the antibodies detect these proteins, they bond with the mesothelioma cell. These antibodies alert the immune system to the presence of mesothelioma cells and destroy them.
Hope for Late Stage Patients
A Phase 2 clinical trial testing the efficacy of tremelimumab in late stage mesothelioma patients is underway at over 102 locations around the globe.
The greatest perceived benefit of tremelimumab is its potential to help chemotherapy-resistant mesothelioma patients. As mesothelioma progresses, there are fewer and fewer effective treatments available. And since chemotherapy is essentially the only real option for late stage patients, drugs like tremelimumab may be a saving grace for them.
A study released in March by Italian doctors corroborated the potential of tremelimumab as a viable treatment for mesothelioma. The study is titled “Efficacy and safety of an intensified schedule of tremelimumab for chemotherapy-resistant malignant mesothelioma: an open-label, single-arm, phase 2 study.”
“Our results suggest that the intensified schedule of tremelimumab investigated seems to have clinical and immunological activity in patients with advanced malignant mesothelioma, and a good safety profile,” the doctors reported.
The doctors also discovered that participants in the study may be able to handle higher doses and decided to explore “the efficacy and safety of an intensified schedule of tremelimumab in patients with advanced malignant mesothelioma.”
The participants in this study all had Stage 3 or 4 mesothelioma and over half of them achieved “disease control” for approximately 10 months, meaning their cancer did not spread during this time. Most of the patients had epithelioid pleural mesothelioma.
Part of the trouble with developing new treatments for mesothelioma is gaining support for meaningful research. Mesothelioma is such a rare disease that it’s hard to fund development that could lead to FDA approval. It’s also hard to fund large clinical trials of these drugs.
“Historically, drug companies have been reluctant to undertake large trials in mesothelioma due to concerns about feasibility and slow accrual,” Dr. Krug said last year.
The clinical trial of tremelimumab, however, is anything but the norm with over 560 participants enrolled. Amazingly, this enrollment took less than two years. To put this in perspective, it often takes more than five years to reach an enrollment like this. Part of this has to do with global collaboration, but it also has to do with promoting the drug in the right way.
Tremelimumab was granted orphan drug status on April 13th of this year. Orphan drug status is a designation given to drugs for rare diseases that allow pharmaceutical companies to market the drug before getting FDA approval. The pharmaceutical company that developed tremelimumab is AstraZeneca, which has developed drugs for many different diseases from Alzheimer’s to lung cancer.
“Our aim is to rapidly advance the development of tremelimumab as a potential new treatment option for these patients,” senior vice president of AstraZeneca Robert Iannone said in a press release.
Tremelimumab, therefore, seems to have all its chips in the right places for success. It has a large clinical trial, it has the support of mesothelioma specialists around the world and it has orphan drug status.