Swiss researchers may have finally found an effective second-line treatment for mesothelioma.
Scientists with the Swiss Group for Clinical Cancer Research presented their findings at the recent European Society for Medical Oncology conference in Barcelona.
Mesothelioma patients who fail after first-line therapy have few options. The new study focused on lurbinectedin, a drug that impacts cancer cells at the DNA level. Early studies suggest lurbinectedin might make a good second-line treatment for small cell lung cancer.
According to the Swiss team, more than half of patients in their study responded to lurbinectedin as a second-line treatment for mesothelioma.
In Search of a Second-Line Mesothelioma Treatment
Malignant mesothelioma is notoriously difficult to diagnose and even harder to treat. It is usually caused by occupational exposure to asbestos. Once asbestos fibers enter the lungs, they stay there indefinitely. Patients can develop mesothelioma even decades after they are exposed.
Once the symptoms of mesothelioma develop, even the best standard treatments may not help much. Only about 40 percent of patients respond to chemotherapy. Those who do usually see a return of their cancer within a few months.
After patients have exhausted first-line therapies, there is no standard second-line treatment for mesothelioma. Some studies show retreatment with chemotherapy can slow the disease down. But researchers around the world are trying to find other, more effective ways to improve mesothelioma survival.
Lurbinectedin Could be the Next Step for Some
Lurbinectedin is an oncogenic transcription inhibitor. According to the National Cancer Institute drug dictionary, it “binds to residue lying in the minor groove of DNA”. This keeps cancer cells from progressing through their normal life phases and may cause them to die early.
The Swiss study of lurbinectedin as a second-line treatment for mesothelioma involved 42 patients. The patients previously received either chemotherapy alone or chemotherapy with immunotherapy. Every patient had eventually relapsed.
Study subjects received 3.2 mg/m2 of lurbinectedin every 3 weeks until their cancer progressed. Researchers had a goal to stop mesothelioma progression for at least 12 weeks in at least 21 patients.
Promising Results for Second-Line Treatment for Mesothelioma
“At cut-off date, progression free survival was met by 22/42 patients,” reported presenter Yannis Metaxas. “One patient had complete, one patient partial response, and 20 patients stable disease as best response.”
Among the patients who responded to lurbinectedin as a second-line treatment for mesothelioma, it took a median of four months for their tumors to grow again. Overall survival in the group was about a year.
Other second- and third-line mesothelioma treatments are not as effective. Median progression-free survival with other options is less than two months. Overall survival with every other second-line treatment for mesothelioma is six to nine months.
But lurbinectedin is not problem-free. Most patients had some complications. A drop in white blood cells and fatigue were the most common issues.
The researchers say the study is a good start, but more work is needed. “Respective patient numbers are small for definitive conclusions,” writes Dr. Metaxas. “Further evaluation of lurbinectedin in a large randomized trial is warranted.”
Metaxas, Y, et al, “SAKK 17/16: Lurbinectedin as second or third line palliative chemotherapy in malignant pleural mesothelioma (MPM): A multi-center, single-arm Phase…”, ESMO 2019 Congress, Annals of Oncology, 2019, https://oncologypro.esmo.org/Meeting-Resources/ESMO-2019-Congress/SAKK-17-16-Lurbinectedin-as-second-or-third-line-palliative-chemotherapy-in-malignant-pleural-mesothelioma-MPM-A-multi-center-single-arm-Phase-II-trial