Dutch researchers say administering maintenance therapy with gemcitabine after chemotherapy may help mesothelioma patients live longer than supportive care alone.
Gemcitabine is an antimetabolite sold under the brand name Gemzar. Oncologists use it to treat several other types of cancer. When cancer cells absorb gemcitabine, they can no longer divide into new cancer cells.
Most mesothelioma patients have chemotherapy as their first-line treatment. If they are healthy enough, they may also have mesothelioma surgery. A maintenance therapy is a treatment that follows the main treatment. It is an effort to maintain the effects of the treatment.
The new Dutch study shows gemcitabine may be a safe and effective choice for maintenance therapy.
What Does Maintenance Therapy Mean?
Right now, there is no cure for mesothelioma. Patients who receive a mesothelioma diagnosis do not have many treatment options. Chemotherapy with Alimta is the primary or first-line mesothelioma treatment for most patients. It is usually combined with another drug called cisplatin.
Unfortunately, this ‘gold standard’ mesothelioma therapy does not work for everyone. Previous studies suggest that chemotherapy alone extends mesothelioma survival by an average of four months.
Maintenance therapy is a second-line treatment that is ongoing. Patients come back to the hospital at regular intervals to get the treatment. An effective maintenance therapy could prolong the effects of chemotherapy and extend mesothelioma survival.
Testing Gemcitabine After Standard Chemotherapy
The new study was conducted by researchers at the Netherlands Cancer Institute in Amsterdam. It included 130 mesothelioma patients from 18 Dutch hospitals. Patients were diagnosed between 2014 and 2019 with unresectable mesothelioma. They had at least four rounds of chemotherapy with no additional mesothelioma progression.
Doctors randomly assigned each patient to one of two groups. The first group received maintenance therapy with gemcitabine along with standard supportive care. The second group had only supportive care.
Patients on the maintenance therapy received 1250 mg/m2 of gemcitabine on days 1 and 8 in 21-day cycles. The treatment stopped if the patient had a severe reaction or if another serious illness came up. Patients could also request to stop.
Promising Results of the Gemcitabine Study
Researchers tracked both groups of mesothelioma patients for a median of three years. Across the board, those on maintenance therapy with gemcitabine had better survival.
“Progression-free survival was significantly longer in the gemcitabine group (median 6·2 months) than in the supportive care group (3·2 months),” writes lead author Cornedine J de Gooijer.
But the treatment was not without complications. More than half of the patients on the maintenance therapy had serious (Grade 3 – 4) adverse events. Only 16 percent of the supportive care group had these kinds of problems. The most common problems were anemia, low white blood cells, fatigue, pain, or infection. One of the 65 mesothelioma patients in the gemcitabine group died.
Still, researchers say the study is proof that Gemzar may help some mesothelioma patients live longer after chemotherapy. “This study confirms the activity of gemcitabine in treating malignant mesothelioma,” says Dr. de Gooijer.
Other drugs and combinations that have been tested as second-line or maintenance therapy for mesothelioma include:
- Additional rounds of pemetrexed
- Taxane and gemcitabine
- Imatinib and gemcitabine
To date, none of these treatments has been shown to extend mesothelioma survival by more than eight months.
De Gooijer, C, et al, “Switch-maintenance gemcitabine after first-line chemotherapy in patients with malignant mesothelioma (NVALT19): an investigator-initiated, randomised, open-label, phase 2 trial”, January 2021, Lancet Respiratory Medicine, Online ahead of print, https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(20)30362-3/fulltext