Standard-of-care treatment for patients with pleural mesothelioma may soon include Tumor Treating Fields, a novel therapy involving electric fields that disrupt cancer cell division and inhibit tumor growth.
In the wake of recently released results from Novocure’s STELLAR phase II clinical trial, the U.S. Food and Drug Administration (FDA) is expected to approve the treatment within the next six months, giving mesothelioma patients another much-needed option.
“At this point, it should be a relatively rapid approval process,” Dr. Eilon Kirson, chief science officer at Novocure, the oncology company designing the therapy, told Asbestos.com. “We’ve been working with the FDA to make it happen. The data is approvable, from a clinical trial design point of view, a statistical point of view, and from a clinical benefit point of view.”
The FDA has not approved a new treatment option for pleural mesothelioma since 2004 when the chemotherapy drug Alimta (pemetrexed) was added.
A 50 Percent Improvement
In the STELLAR clinical trial, Tumor Treating Fields was combined with standard chemotherapy — Alimta and either cisplatin or carboplatin — and compared to a historical control model of standard chemotherapy alone.
The results include an 18.2-month median overall survival for the Tumor Treating Fields group, a significant improvement over the 12.1 months for those receiving only chemotherapy. There was no reported increase in systemic toxicity.
“It’s not the cure we’re all looking for, but it means that some patients are seeing a significant benefit,” Kirson said. “It’s a jump forward. If approved, it can change the outcome of this disease, make it that much less horrific.”
The clinical trial was held at multiple cancer centers across Europe and included 80 patients with unresectable, previously untreated, malignant pleural mesothelioma.
Of those patients, 66 percent had the epithelioid histology, 56 percent were smokers, and the median age was 67.
The final results of the trial will be presented later this month in Toronto at the 19th annual World Conference on Lung Cancer, hosted by the International Association for the Study of Lung Cancer.
Secondary endpoints in the trial also showed improvement over the historical controls, which were established in 2003 as part of the Alimta approval. The historical control included a similar percentage of patients with epithelioid histology.
The Tumor Treating Fields median progression-free survival was 7.6 months, compared to 5.7 months. A clinical benefit, which includes either partial response or stable disease, was found in 97.2 percent of patients.
Skin irritation was seen in 46 percent of the patients, but only 4 percent reported grade 3 skin irritation.
Already Approved for Brain Cancer
Tumor Treating Fields was first approved by the FDA in 2011 for use with glioblastoma, the type of brain cancer that recently killed U.S. Sen. John McCain from Arizona. McCain had not been treated with with novel therapy.
The FDA gave Tumor Treating Fields a Humanitarian Use Device designation for pleural mesothelioma in 2017, which provided an opportunity for limited use.
Novocure has been seeking a Humanitarian Device Exemption, which would allow a full, broader use of the therapy for mesothelioma when used with chemotherapy.
The company also is conducting clinical trials for its use with lung cancer, pancreatic cancer and ovarian cancer.
With FDA approval, Kirson said it should be available in 2019 for pleural mesothelioma patients.
“Our mission is to improve patients’ survival without the toxicity you get with systemic chemotherapy,” he said. “If we can move it from treating brain tumors to the chest, it would not only help mesothelioma patients, but it would open the door for treating other cancers, too.”