The Baylor College of Medicine in Houston has begun exploring the effectiveness of specific immunotherapy drugs in combination with aggressive surgery for patients with malignant pleural mesothelioma.
The single-center, clinical trial has the potential to extend lives and alter the current multidisciplinary approach to treatment.
“It will allow us to gain a much deeper understanding for how these drugs work with mesothelioma,” Dr. Bryan Burt, thoracic surgical oncologist at Baylor and primary trial investigator, told Asbestos.com. “There definitely could be a benefit [for the patients]. These drugs have proven very effective in solid tumors.”
The trial, which officially began the patient enrollment process last week, will determine if durvalumab (MED14736) or durvalumab plus tremelimumab is a more effective drug combination with aggressive surgery.
The clinical trial’s control group will include four patients who will undergo the same surgeries but without the drugs.
Both immunotherapy agents are known as checkpoint inhibitors.
These are drugs created with human antibodies that theoretically unmask the cancer cells and unleash a patient’s own immune system to attack.
To remain hidden from the immune system, cancer cells make proteins that indicate they’re healthy, normal cells. Checkpoint inhibitors track down those proteins, allowing the immune system to recognize the cells as cancerous.
The inhibitors are administered via intravenous infusion two to three weeks before surgery, prompting the immune system to mount an attack before operation.
After surgical removal of the tumors, the patients will receive intraoperative chemotherapy using cisplatin, a standard of care at Baylor Medical Center.
Renowned mesothelioma specialist Dr. David Sugarbaker will head the thoracic surgical team. Sugarbaker also serves as director of the Lung Institute at Baylor.
Sugarbaker joined Baylor in 2014 after spending more than two decades at Brigham and Women’s Hospital in Boston, where he built his reputation and pioneered some surgical advancements used today at most specialty centers. He also founded the world-famous International Mesothelioma Program.
One of his goals at Baylor: Utilize the center’s vast resources to build the best mesothelioma program in the world.
Patients with any mesothelioma histology (sarcomatoid, epithelial, or mixed) can participate in this trial, which is expected to end in early 2018.
The recent success of immunotherapy in many cancer studies, and particularly the combination of durvalumab and tremelimumab in lung cancer, fuels the optimism surrounding this trial.
A recent Moffitt Cancer Center study of non-small cell lung cancer showed the same immunotherapy combination achieved stable disease in 11 of 31 patients. And another eight patients achieved a partial response from the treatment. The therapy showed acceptable safety and efficacy.
The theory in using it as a pre-surgery treatment is to achieve more favorable alterations of the intratumoral immune system environment. It could make the surgery more complete and possibly reduce the rate of recurrence, which is a real problem with this disease.
Tremelimumab, an effective drug when used alone for some cancers, failed an efficacy test in a recent clinical trial for mesothelioma. Although the trial was stopped, researchers still believed it could play a positive role when combined with other immunotherapy drugs.
“In previous trials, and pre-clinical models, there was a synergy between two different checkpoint inhibitors,” Burt said. “A lot of clinical trials have suggested that mesothelioma will respond [to this combination].”
Mesothelioma is a relatively rare and aggressive cancer caused by exposure to asbestos. It typically starts in the thin lining surrounding the lungs, but it often has metastasized before doctors identify it.
The U.S. Food and Drug Administration has not approved a second-line therapy for mesothelioma, making recurrence difficult to treat.